Antibacterials
INDIVIDUAL AGENTS
First-generation oral cephalosporin. Narrow spectrum relative to second-generation agents within this class.
Penicillin cross-reactivity: Aminocephalosporin — estimated cross-reactivity 16.45% in confirmed aminopenicillin allergy. 1
Microbiome impact: Low to moderate. 4
AAD risk: Moderate. Lower than cefuroxime within this class.
Form: Capsules and tablets. Oral suspension available.
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label.
SmPC: Cefalexin SmPC ↗
Dosing per SmPC and BNF.
Food: Can be taken with or without food. Taking with food is recommended to minimise GI side effects during training.
AAD risk: Moderate within class. Less strongly associated with C. difficile-associated diarrhoea than cefuroxime. 2
GI side effects: Nausea and diarrhoea reported. Taking with food reduces GI side effects and is recommended during training periods.
Photosensitivity: Not a concern with cefalexin. No outdoor training restrictions required.
GI tolerability: Generally well tolerated. GI side effects during a course may affect training nutrition and hydration targets.
Microbiome disruption: Low to moderate. Short-course impact likely limited and reversible. Probiotic consideration may be appropriate — see TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive — see SmPC for full interaction profile.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc: No clinically significant absorption interaction established for cefalexin.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.09 per 500mg capsule.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Second-generation oral cephalosporin. Broader spectrum than cefalexin.
Penicillin cross-reactivity: Aminocephalosporin — estimated cross-reactivity 16.45% in confirmed aminopenicillin allergy. 1
Microbiome impact: Low to moderate. Minor, reversible anaerobic flora changes documented in volunteer data. Normalisation within one week of stopping treatment. 3
AAD risk: Moderate. Class effect applies. Direct evidence for cefaclor-specific AAD risk is limited — risk inferred from cephalosporin class data. 3
Form: Capsules and tablets. Modified-release tablets and oral suspension available.
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label.
SmPC: Cefaclor SmPC ↗
Dosing per SmPC and BNF.
Food: Can be taken with or without food. Taking with food recommended to minimise GI side effects during training.
AAD risk: Moderate. Class effect applies. GI side effects may affect hydration, electrolyte balance, and training nutrition during treatment course.
GI side effects: Nausea and diarrhoea reported. Taking with food reduces GI side effects and is recommended during training periods.
Photosensitivity: Not a concern with cefaclor. No outdoor training restrictions required.
GI tolerability: Generally well tolerated. GI side effects during a course may affect training nutrition and hydration targets.
Microbiome disruption: Low to moderate. Short-course impact limited and reversible within one week of stopping treatment. Probiotic consideration may be appropriate — see TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive — see SmPC for full interaction profile.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc: No clinically significant absorption interaction established for cefaclor.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.36 per 500mg capsule.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Second-generation oral cephalosporin. Broader spectrum than cefalexin and cefaclor within this class.
Penicillin cross-reactivity: Intermediate R1 side-chain similarity to penicillins. Estimated cross-reactivity 5.6% in confirmed penicillin allergy. Lower risk than aminocephalosporins but not negligible. 1
Microbiome impact: Moderate. More noticeable dysbiosis than cefalexin or cefaclor consistent with broader spectrum. 5
AAD risk: Moderate to high. Cefuroxime associated with significantly elevated C. difficile-associated diarrhoea risk. 2
Form: Tablets.
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label.
SmPC: Cefuroxime axetil SmPC ↗
Dosing per SmPC and BNF.
Food: Absorption significantly enhanced when taken with or shortly after food. Taking with food is recommended and improves bioavailability as well as reducing GI side effects during training.
AAD risk: Moderate to high. Cefuroxime associated with significantly elevated C. difficile-associated diarrhoea risk. May affect hydration, electrolyte balance, and training nutrition during treatment course. 2
GI side effects: Nausea and diarrhoea reported. Taking with food reduces GI side effects and is recommended during training periods.
Photosensitivity: Not a concern with cefuroxime axetil. No outdoor training restrictions required.
GI tolerability: Higher GI risk within this class. AAD and GI side effects during a course may affect training nutrition and hydration targets more significantly than with cefalexin or cefaclor.
Microbiome disruption: Moderate. Broader spectrum associated with more noticeable dysbiosis than first-generation agents. Probiotic consideration may be appropriate — see TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive — see SmPC for full interaction profile.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc: No clinically significant absorption interaction established for cefuroxime axetil.
Antacids and acid-suppressing medicines (PPIs, H2 antagonists): Medicines that reduce gastric acidity may reduce cefuroxime axetil bioavailability and cancel the absorption benefit of taking with food. SmPC Concurrent PPI use also associated with increased CDAD risk where cefuroxime is prescribed. 2
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.65 per 250mg tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Systemic fluoroquinolones must only be prescribed when other commonly recommended antibiotics are inappropriate. Situations where use may be appropriate include resistance to first-line antibiotics, contraindication to first-line antibiotics, side effects requiring cessation of first-line treatment, or failure of first-line treatment.
Tendon damage: Risk of tendinitis and tendon rupture. Onset may occur within 48 hours of starting treatment or be delayed for months after stopping. Risk significantly increased by concurrent corticosteroid use — a common combination in elite sport.
Disabling and potentially irreversible side effects affecting musculoskeletal, neurological, psychiatric and sensory systems have been reported. Estimated minimum frequency 1 in 10,000 patients.
Stop immediately and seek medical review at first signs of tendon pain or swelling, joint pain or swelling, abnormal sensations, muscle weakness, severe fatigue, mood disturbance, sleep disorder, or changes in vision, taste, smell or hearing.
Source: MHRA Drug Safety Update. January 2024. Full guidance ↗
INDIVIDUAL AGENTS
Most widely prescribed fluoroquinolone in UK primary care. Broad-spectrum activity. Subject to MHRA 2024 prescribing restrictions — see class warning box.
Tendon risk: Applicable as per class. Achilles tendon most commonly reported. Risk increased with concurrent corticosteroid use, high training loads, and pre-existing tendon pathology.
Photosensitivity: Moderate. Relevant for outdoor athletes during treatment course.
QTc prolongation: Class effect. Lower QTc risk than moxifloxacin but not negligible. Relevant in athletes with unscreened cardiac status.
Microbiome impact: High. Significant reduction in gut microbial diversity reported, with some evidence of effects persisting up to one year after stopping treatment. 6
AAD risk: High.
Form: Tablets.
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label. Verify local regulatory status before international travel.
SmPC: Ciprofloxacin SmPC ↗
Dosing per SmPC and BNF.
Food: Can be taken with or without food. Taking with food recommended to minimise GI side effects. Avoid taking with dairy products or calcium-fortified foods and drinks as these reduce absorption. Where a meal contains dairy or fortified products, take at least two hours before or six hours after.
Supplement timing: Iron, calcium, magnesium, zinc, and multivitamin supplements significantly reduce ciprofloxacin absorption. Separate dosing by at least two hours before or six hours after ciprofloxacin dose.
Outdoor training and photosensitivity: Avoid prolonged sun exposure during treatment course. Additional sun protection measures recommended for outdoor training and competition.
Tendon risk: Applicable as per class warning. Stop immediately at first signs of tendon pain or swelling.
CNS effects: Insomnia, anxiety, and dizziness reported. May affect sleep quality and performance during treatment course.
Photosensitivity: Moderate. Sun protection required for outdoor training and competition.
AAD risk: High. GI side effects may affect hydration, electrolyte balance, and training nutrition.
GI side effects: Nausea and diarrhoea reported. Taking with food recommended during training periods. Avoid dairy and calcium-fortified foods at time of dosing.
Tendon and musculoskeletal: Delayed onset tendon symptoms possible months after completing a course. Clinical review warranted at first signs of tendon pain or swelling following recent ciprofloxacin use.
CNS and sleep: Insomnia and anxiety may affect recovery quality during treatment course.
Microbiome disruption: High. Significant gut microbial diversity reduction reported, with effects potentially persisting up to one year. Probiotic consideration appropriate — see TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive — see SmPC for full interaction profile.
Iron, calcium, magnesium, zinc, and multivitamins: Significantly reduce ciprofloxacin absorption. Separate dosing by at least two hours before or six hours after ciprofloxacin dose.
Dairy and calcium-fortified foods and drinks: Reduce absorption. Where a meal contains dairy or fortified products, take at least two hours before or six hours after.
Corticosteroids: Concurrent use significantly increases tendon rupture risk. Avoid co-administration where possible. [MHRA 2024]
NSAIDs: Concurrent use may increase risk of CNS side effects including seizures. Caution warranted given prevalence of NSAID use in elite sport.
Caffeine: Ciprofloxacin inhibits caffeine metabolism, increasing plasma caffeine levels. Athletes using caffeine as a performance supplement should be aware of potential for increased caffeine side effects during a ciprofloxacin course.
QTc-prolonging medicines: Additive QTc prolongation risk.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.39 per 500mg tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Fluoroquinolone with activity broadly similar to ciprofloxacin but with enhanced gram-positive and atypical organism coverage. Subject to MHRA 2024 prescribing restrictions — see class warning box.
Tendon risk: Applicable as per class. Achilles tendon most commonly reported. Risk increased with concurrent corticosteroid use, high training loads, and pre-existing tendon pathology.
Photosensitivity: Moderate to high. More significant photosensitivity signal than ciprofloxacin. Relevant for outdoor athletes during treatment course.
QTc prolongation: Class effect. Higher QTc risk than ciprofloxacin. Relevant in athletes with unscreened cardiac status.
Microbiome impact: High. Significant reduction in gut microbial diversity reported. 6
AAD risk: High.
Form: Tablets.
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label. Verify local regulatory status before international travel.
SmPC: Levofloxacin SmPC ↗
Dosing per SmPC and BNF.
Food: Can be taken with or without food. Taking with food recommended to minimise GI side effects. Avoid taking with dairy products or calcium-fortified foods and drinks as these reduce absorption. Where a meal contains dairy or fortified products, take at least two hours before or six hours after.
Supplement timing: Iron, calcium, magnesium, zinc, and multivitamin supplements significantly reduce levofloxacin absorption. Separate dosing by at least two hours before or six hours after levofloxacin dose.
Outdoor training and photosensitivity: Avoid prolonged sun exposure during treatment course. Additional sun protection measures recommended for outdoor training and competition. Photosensitivity risk higher than ciprofloxacin.
Tendon risk: Applicable as per class warning. Stop immediately at first signs of tendon pain or swelling.
CNS effects: Insomnia, anxiety, and dizziness reported. May affect sleep quality and performance during treatment course.
Photosensitivity: Moderate to high. More significant than ciprofloxacin. Sun protection required for all outdoor training and competition during treatment course.
AAD risk: High. GI side effects may affect hydration, electrolyte balance, and training nutrition.
GI side effects: Nausea and diarrhoea reported. Taking with food recommended during training periods. Avoid dairy and calcium-fortified foods at time of dosing.
Tendon and musculoskeletal: Delayed onset tendon symptoms possible months after completing a course. Clinical review warranted at first signs of tendon pain or swelling following recent levofloxacin use.
CNS and sleep: Insomnia and anxiety may affect recovery quality during treatment course.
Microbiome disruption: High. Significant gut microbial diversity reduction reported. Probiotic consideration appropriate — see TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive — see SmPC for full interaction profile.
Iron, calcium, magnesium, zinc, and multivitamins: Significantly reduce levofloxacin absorption. Separate dosing by at least two hours before or six hours after levofloxacin dose.
Dairy and calcium-fortified foods and drinks: Reduce absorption. Where a meal contains dairy or fortified products, take at least two hours before or six hours after.
Corticosteroids: Concurrent use significantly increases tendon rupture risk. Avoid co-administration where possible. [MHRA 2024]
NSAIDs: Concurrent use may increase risk of CNS side effects including seizures. Caution warranted given prevalence of NSAID use in elite sport.
QTc-prolonging medicines: Additive QTc prolongation risk. Higher QTc signal than ciprofloxacin — greater caution warranted.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £1.19 per 500mg tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
INDIVIDUAL AGENTS
Licensed indications include: Respiratory tract infections, skin and soft tissue infections, and some sexually transmitted infections.
QTc prolongation: Highest QTc risk within the macrolide class. Relevant in athletes with unscreened cardiac status. Clinical consideration warranted before prescribing in this population.
GI side effects: Moderate within the class. Better tolerated than erythromycin. Short course (typically 3 to 5 days) limits overall GI burden during treatment.
Microbiome impact: Low to moderate. Short course duration limits cumulative disruption relative to longer macrolide courses.
AAD risk: Low to moderate. Short course reduces overall risk relative to longer antibiotic courses.
Form: Tablets (250mg, 500mg). Oral suspension available.
Route: Oral
Travel: Tablets — no restrictions. Carry original packaging with dispensing label.
Oral suspensions — check airline carry-on rules for volumes over 100ml. Verify local regulatory status before international travel.
SmPC: Azithromycin SmPC ↗
Dosing per SmPC and BNF.
Food: Can be taken with or without food. Taking with food recommended to minimise GI side effects during training.
Administration: Short course typically 3 to 5 days. Compliance advantage over longer courses in athletes managing training schedules.
QTc prolongation: Highest QTc risk within this class. Relevant in athletes with unscreened cardiac status.
GI side effects: Nausea, vomiting, and abdominal discomfort reported. Better tolerated than erythromycin. Taking with food recommended during training periods.
AAD risk: Low to moderate. Short course limits overall GI disruption.
Photosensitivity: Not a significant concern. No outdoor training restrictions required.
GI tolerability: Generally better tolerated than other macrolides. Short course limits impact on training nutrition and hydration targets.
Microbiome disruption: Low to moderate. Short course duration limits cumulative gut flora disruption. Probiotic consideration may be appropriate. See TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
QTc-prolonging medicines: Additive QTc prolongation risk. Caution where athlete is prescribed other QTc-prolonging agents.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc: No clinically significant absorption interaction established for azithromycin.
Antacids containing aluminium or magnesium: May reduce peak plasma concentration of azithromycin. Separate dosing by at least two hours. [SmPC]
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.17 per 250mg tablet. Approximately £0.26 per 500mg tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Respiratory tract infections, skin and soft tissue infections, Helicobacter pylori eradication (in combination), and some sexually transmitted infections.
CYP3A4 inhibition: Clarithromycin is a potent CYP3A4 inhibitor. Multiple clinically significant drug interactions relevant in sport. See Field 6.
QTc prolongation: Moderate QTc risk within the macrolide class. Lower than azithromycin but not negligible. Relevant in athletes with unscreened cardiac status.
GI side effects: Moderate within the class. Abnormal taste (dysgeusia) commonly reported and may affect dietary intake during treatment course.
Microbiome impact: Moderate. Decreased Bifidobacterium and Lactobacillus populations reported for up to five weeks after stopping treatment. 6
AAD risk: Moderate.
Form: Tablets (250mg, 500mg). Modified-release tablets (500mg). Oral suspension available.
Route: Oral
Travel: Tablets — no restrictions. Carry original packaging with dispensing label.
Oral suspensions — check airline carry-on rules for volumes over 100ml. Verify local regulatory status before international travel.
SmPC: Clarithromycin SmPC ↗
Dosing per SmPC and BNF.
Food: Can be taken with or without food. Taking with food recommended to minimise GI side effects during training. Modified-release tablets should be taken with food.
Taste disturbance: Dysgeusia (abnormal or metallic taste) commonly reported. May affect appetite and dietary intake during treatment course.
GI side effects: Nausea, vomiting, abdominal discomfort, and diarrhoea reported. Dysgeusia commonly reported and may affect appetite and dietary intake during training. Taking with food recommended.
AAD risk: Moderate. GI side effects may affect hydration, electrolyte balance, and training nutrition during treatment course.
QTc prolongation: Moderate risk. Relevant in athletes with unscreened cardiac status.
Photosensitivity: Not a significant concern. No outdoor training restrictions required.
GI tolerability: Moderate GI burden. Dysgeusia and GI side effects may affect training nutrition and hydration targets during treatment course.
Microbiome disruption: Moderate. Decreased Bifidobacterium and Lactobacillus populations reported for up to five weeks after stopping treatment. 6 Probiotic consideration may be appropriate. See TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
CYP3A4 inhibition: Clarithromycin is a potent CYP3A4 inhibitor. The following interactions are particularly relevant in elite sport:
Statins (simvastatin, atorvastatin): Clarithromycin significantly increases statin plasma levels. Risk of myopathy and rhabdomyolysis. Avoid concurrent use with simvastatin. Use with caution with atorvastatin. [SmPC]
Colchicine: Clarithromycin increases colchicine plasma levels. Risk of colchicine toxicity including neuromuscular toxicity. Avoid concurrent use. [SmPC]
Anxiolytics (midazolam, triazolam): Clarithromycin significantly increases plasma levels. Relevant where short-term anxiolytic use occurs in sport. [SmPC]
QTc-prolonging medicines: Additive QTc prolongation risk.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc: No clinically significant absorption interaction established for clarithromycin.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.09 per 250mg tablet. Approximately £0.14 per 500mg tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Respiratory tract infections, skin and soft tissue infections, acne vulgaris, and some sexually transmitted infections. An alternative for penicillin-allergic patients.
GI side effects: Highest GI burden within the macrolide class. Nausea, vomiting, and abdominal cramps frequently reported. Directly relevant to training nutrition and hydration in athletes. See Field 4.
QTc prolongation: Moderate QTc risk within the macrolide class. Relevant in athletes with unscreened cardiac status.
Microbiome impact: Moderate. Class effect applies.
AAD risk: Moderate to high within the macrolide class.
Largely superseded: Erythromycin has been largely superseded by azithromycin and clarithromycin in UK primary care due to its inferior GI tolerability profile and twice to four times daily dosing schedule. Where macrolide therapy is indicated, azithromycin or clarithromycin are generally preferred in the athlete context.
Form: Tablets and gastro-resistant tablets (250mg, 500mg). Oral suspension available in multiple strengths (125mg/5ml, 250mg/5ml, 500mg/5ml; sugar-free versions available).
Route: Oral
Travel: Tablets — no restrictions. Carry original packaging with dispensing label.
Oral suspensions — check airline carry-on rules for volumes over 100ml. Verify local regulatory status before international travel.
SmPC: Erythromycin SmPC ↗
Dosing per SmPC and BNF.
Food: Absorption reduced by food for standard formulations. Take on an empty stomach where possible. Gastro-resistant formulations may be taken with food — verify per dispensed product SmPC.
Dosing frequency: Twice to four times daily schedule may require practical discussion with the athlete around training and meal timing. Multiple daily doses increase cumulative GI exposure during training periods.
GI side effects: Highest GI burden within the macrolide class. Nausea, vomiting, and abdominal cramps frequently reported. May significantly affect dietary intake, training nutrition, and hydration during treatment course. Gastro-resistant formulations may reduce upper GI side effects.
AAD risk: Moderate to high within the macrolide class. GI side effects may affect hydration, electrolyte balance, and training nutrition during treatment course.
QTc prolongation: Moderate risk. Relevant in athletes with unscreened cardiac status.
Dosing schedule: Multiple daily doses require practical management around training and meal timing during treatment course.
Photosensitivity: Not a significant concern. No outdoor training restrictions required.
GI tolerability: Highest GI burden within the macrolide class. GI side effects may significantly affect training nutrition and hydration targets during treatment course, with downstream impact on recovery capacity. Azithromycin or clarithromycin preferred where macrolide therapy is indicated.
Microbiome disruption: Moderate. Probiotic consideration may be appropriate. See TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
QTc-prolonging medicines: Additive QTc prolongation risk.
Statins (simvastatin, atorvastatin): Erythromycin inhibits CYP3A4 — increases statin plasma levels. Risk of myopathy. Use with caution. [SmPC]
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc: No clinically significant absorption interaction established for erythromycin.
Antacids: May reduce absorption of some erythromycin formulations. Separate dosing where possible.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.07 per 250mg gastro-resistant tablet. Approximately £0.36 per 500mg standard tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Bacterial infections caused by anaerobic organisms including dental infections, bacterial vaginosis, and certain gastrointestinal infections. Also used in the treatment and prevention of protozoal infections.
Alcohol interaction: Concurrent alcohol use causes a disulfiram-like reaction: flushing, nausea, vomiting, tachycardia. Avoid alcohol during treatment and for at least 48 hours after completing the course. Highly relevant in team sport environments. See Field 6.
Microbiome impact: Moderate. Primarily disrupts anaerobic flora. Probiotic consideration may be appropriate — see TAF Probiotics entry.
AAD risk: Low to moderate. Lower than broad-spectrum agents but GI side effects common. See Field 4.
Metallic taste: Frequently reported. May affect dietary intake and appetite during treatment course.
Form: Tablets (200mg, 400mg). Oral suspension available.
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label. Verify local regulatory status before international travel.
SmPC: Metronidazole SmPC ↗
Dosing per SmPC and BNF.
Food: Take with or after food to reduce GI side effects. Recommended during training periods to minimise nausea and GI disturbance.
GI side effects: Nausea, vomiting, and metallic taste frequently reported. May affect dietary intake, appetite, and training nutrition during treatment course. Taking with food recommended.
AAD risk: Low to moderate. Lower disruption than broad-spectrum agents.
Fatigue and dizziness: Reported with metronidazole use. May affect training tolerance and concentration during treatment course.
Photosensitivity: Not a significant concern. No outdoor training restrictions required.
GI tolerability: Nausea and metallic taste may affect nutrition and hydration targets during treatment course, with downstream impact on recovery.
Microbiome disruption: Moderate. Primarily affects anaerobic flora. Probiotic consideration may be appropriate — see TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive — see SmPC for full interaction profile.
Alcohol: Concurrent use causes a disulfiram-like reaction: flushing, nausea, vomiting, tachycardia. Avoid alcohol during treatment and for at least 48 hours after completing the course. This applies to alcohol in any form including alcohol-containing mouthwashes and some sports recovery products.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc: No clinically significant absorption interaction established for metronidazole.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.05 per 400mg tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Uncomplicated lower urinary tract infections.
Renal function: Nitrofurantoin requires adequate renal function to achieve therapeutic urinary concentrations. Contraindicated in significant renal impairment. Potential for renal impairment in athletes taking long-term or high-dose NSAIDs worth considering. See SmPC for eGFR thresholds.
Pulmonary toxicity: Rare but serious. Dyspnoea and cough during treatment in an endurance athlete warrants prompt clinical review.
Microbiome impact: Low. Acts locally in the urinary tract with minimal systemic absorption. Lowest microbiome impact of included antibacterials. Probiotic consideration unlikely to be necessary for short courses but may be considered — see TAF Probiotics entry.
AAD risk: Low. Minimal disruption to gut flora compared to systemic antibiotics.
Form: Capsules (50mg). Modified-release capsules (100mg). Oral suspension available.
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label. Verify local regulatory status before international travel.
SmPC: Nitrofurantoin SmPC ↗
Dosing per SmPC and BNF.
Food: Absorption significantly enhanced when taken with food. Taking with food is recommended and improves bioavailability as well as reducing GI side effects during training.
GI side effects: Nausea and vomiting reported, particularly with immediate-release formulations. Modified-release formulation associated with lower GI side effect incidence. Taking with food recommended during training periods.
Pulmonary toxicity: Rare but serious. Dyspnoea and cough during treatment in an endurance athlete warrants prompt clinical review.
AAD risk: Low. Minimal systemic absorption limits gut flora disruption.
Photosensitivity: Not a significant concern. No outdoor training restrictions required.
GI tolerability: Modified-release formulation generally better tolerated than immediate-release. GI side effects unlikely to significantly affect recovery capacity in most athletes on standard short courses.
Microbiome disruption: Low. Minimal systemic absorption means gut flora largely unaffected. Probiotic consideration not routinely required for short courses.
Selected interactions relevant to common athlete use patterns. Not exhaustive — see SmPC for full interaction profile.
NSAIDs: No direct pharmacokinetic interaction. However concurrent long-term or high-dose NSAID use may impair renal function, reducing nitrofurantoin efficacy and increasing risk of toxicity. See Field 1.
Antacids containing magnesium trisilicate: Reduce nitrofurantoin absorption and urinary excretion. Avoid concurrent use.
Iron, calcium, magnesium, zinc supplements: No clinically significant absorption interaction established for nitrofurantoin beyond the magnesium trisilicate antacid note above.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.68 per 100mg modified-release capsule.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
INDIVIDUAL AGENTS
Licensed indications include: Respiratory tract infections, urinary tract infections, skin and soft tissue infections, dental infections, and some sexually transmitted infections.
Penicillin cross-reactivity: Aminopenicillin. Cross-reactivity with aminocephalosporins (cefalexin, cefaclor) estimated at 16.45% in confirmed aminopenicillin allergy due to shared R1 side chain. Document allergy clearly. See TAF Cephalosporins entry. 1
AAD risk: Moderate. Lower than co-amoxiclav within the class.
Microbiome impact: Moderate. Broader impact than phenoxymethylpenicillin but lower than co-amoxiclav. 6
GI side effects: Moderate. Generally well tolerated relative to co-amoxiclav.
Form: Capsules (250mg, 500mg). Oral suspension available.
Route: Oral
Travel: Capsules — no restrictions. Carry original packaging with dispensing label.
Oral suspensions — check airline carry-on rules for volumes over 100ml. Verify local regulatory status before international travel.
SmPC: Amoxicillin SmPC ↗
Dosing per SmPC and BNF.
Food: Can be taken with or without food. Taking with food recommended to minimise GI side effects during training.
Supplement timing: No separation required from iron, calcium, magnesium, zinc, or dairy.
GI side effects: Nausea, vomiting, and diarrhoea reported. Generally better tolerated than co-amoxiclav. Taking with food recommended during training periods.
AAD risk: Moderate. GI side effects may affect hydration, electrolyte balance, and training nutrition during treatment course.
Photosensitivity: Not a concern. No outdoor training restrictions required.
GI tolerability: Generally well tolerated. GI side effects may affect training nutrition and hydration targets during treatment course.
Microbiome disruption: Moderate. Lower disruption than co-amoxiclav. Probiotic consideration may be appropriate. See TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc, and multivitamins: No clinically significant absorption interaction established for amoxicillin.
Oral contraceptives: No clinically significant pharmacokinetic interaction established based on current evidence.
Methotrexate: Amoxicillin may reduce renal excretion of methotrexate, increasing toxicity risk. [SmPC]
WADA: Not Prohibited 2026.
POM in the UK. Prescription required. Available without prescription in some jurisdictions. Verify local regulatory status before international travel or competition.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.04 per 250mg capsule. Approximately £0.06 per 500mg capsule.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Respiratory tract infections, skin and soft tissue infections, dental infections, and urinary tract infections where caused by beta-lactamase-producing organisms.
Penicillin cross-reactivity: Aminopenicillin component (amoxicillin). Cross-reactivity with aminocephalosporins estimated at 16.45% in confirmed aminopenicillin allergy. Document allergy clearly. See TAF Cephalosporins entry. 1
AAD risk: High. Highest AAD risk within the penicillin class and among the highest of all included antibacterials. C. difficile-associated diarrhoea risk significantly elevated. GI side effects may substantially affect training nutrition and hydration. 2
Microbiome impact: High. Significant dysbiosis reported. Probiotic consideration strongly recommended. See TAF Probiotics entry. 6
GI side effects: Highest GI burden within the penicillin class. Taking at the start of a meal significantly reduces GI side effects and is recommended. See Field 3.
Form: Tablets (250mg/125mg, 500mg/125mg, 875mg/125mg). Oral suspension available.
Route: Oral
Travel: Tablets — no restrictions. Carry original packaging with dispensing label.
Oral suspensions — check airline carry-on rules for volumes over 100ml. Verify local regulatory status before international travel.
SmPC: Co-amoxiclav SmPC ↗
Dosing per SmPC and BNF.
Food: Take at the start of a meal. This significantly reduces GI side effects and improves tolerability during training. Do not take on an empty stomach. [SmPC]
Supplement timing: No separation required from iron, calcium, magnesium, zinc, or dairy.
GI side effects: Highest GI burden within the penicillin class. Nausea, vomiting, and diarrhoea frequently reported. May significantly affect dietary intake, training nutrition, and hydration during treatment course. Taking at the start of a meal is essential to reduce GI burden.
AAD risk: High. C. difficile-associated diarrhoea risk significantly elevated. May substantially affect hydration, electrolyte balance, and training nutrition during treatment course. 2
Photosensitivity: Not a concern. No outdoor training restrictions required.
QTc prolongation: Not a concern.
GI tolerability: Highest GI burden within the penicillin class. GI side effects may significantly affect training nutrition and hydration targets during treatment course, with downstream impact on recovery capacity.
Microbiome disruption: High. Significant dysbiosis reported. Probiotic consideration strongly recommended for athletes prescribed co-amoxiclav. See TAF Probiotics entry. 6
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc, and multivitamins: No clinically significant absorption interaction established for co-amoxiclav.
Oral contraceptives: No clinically significant pharmacokinetic interaction established based on current evidence.
Methotrexate: Co-amoxiclav may reduce renal excretion of methotrexate, increasing toxicity risk. [SmPC]
Anticoagulants (warfarin): Co-amoxiclav may enhance anticoagulant effect. Relevant where warfarin is co-prescribed. [SmPC]
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.07 per 250/125mg tablet. Approximately £0.09 per 500/125mg tablet. Approximately £0.43 per 875/125mg tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Skin and soft tissue infections caused by staphylococci, including infected wounds, infected skin conditions, and soft tissue infections. First-line agent for cellulitis and soft tissue infections in athletes.
Penicillin cross-reactivity: Isoxazolyl penicillin. R1 side chain differs significantly from aminopenicillins. Cross-reactivity risk lower than aminopenicillins but penicillin allergy still applies. Document allergy clearly. See TAF Cephalosporins entry. 1
AAD risk: Low to moderate. Narrower spectrum limits gut flora disruption relative to co-amoxiclav.
Microbiome impact: Low to moderate. Narrower spectrum than co-amoxiclav limits dysbiosis.
Food interaction: Must be taken on an empty stomach. Absorption significantly reduced by food. Relevant for athletes managing dosing around training and meal schedules. See Field 3.
Form: Capsules (250mg, 500mg). Oral solution available.
Route: Oral
Travel: Capsules — no restrictions. Carry original packaging with dispensing label.
Oral solutions — check airline carry-on rules for volumes over 100ml. Verify local regulatory status before international travel.
SmPC: Flucloxacillin SmPC ↗
Dosing per SmPC and BNF.
Food: Must be taken on an empty stomach at least 30 minutes before food, or 2 hours after food. Absorption significantly reduced if taken with or after food. [SmPC] Athlete meal timing and training schedule should be considered when planning dosing times.
Supplement timing: No separation required from iron, calcium, magnesium, zinc, or dairy.
GI side effects: Nausea and GI disturbance reported but generally mild relative to co-amoxiclav. Taking on an empty stomach as required may increase GI discomfort in some athletes.
AAD risk: Low to moderate. Narrower spectrum limits gut flora disruption and associated diarrhoea risk.
Food restriction: Requirement to take on an empty stomach may require practical adjustment to training and meal schedules during treatment course.
Photosensitivity: Not a concern. No outdoor training restrictions required.
GI tolerability: Generally well tolerated. Food restriction requirement may require practical adjustment to training and nutrition schedules during treatment course.
Microbiome disruption: Low to moderate. Narrower spectrum limits gut flora disruption. Probiotic consideration may be appropriate for longer courses. See TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc, and multivitamins: No clinically significant absorption interaction established for flucloxacillin.
Methotrexate: Flucloxacillin may reduce renal excretion of methotrexate, increasing toxicity risk. [SmPC]
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.04 per 250mg capsule. Approximately £0.08 per 500mg capsule.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Streptococcal infections including tonsillitis and pharyngitis, otitis media, dental infections, and prophylaxis against rheumatic fever and pneumococcal infection.
Penicillin cross-reactivity: Narrow-spectrum penicillin with a distinct R1 side chain from aminopenicillins (amoxicillin, ampicillin). Cross-reactivity with cephalosporins is lower than for aminopenicillins. Document allergy clearly. See TAF Cephalosporins entry. 1
AAD risk: Low. Lowest AAD risk within the penicillin class due to narrow spectrum.
Microbiome impact: Low. Lowest microbiome impact of all included penicillins. Very limited gut flora disruption reported. 6
Food interaction: Must be taken on an empty stomach. Absorption significantly reduced by food. Relevant for athletes managing dosing around training and meal schedules. See Field 3.
Form: Tablets (250mg, 500mg). Oral solution available.
Route: Oral
Travel: Tablets — no restrictions. Carry original packaging with dispensing label.
Oral solutions — check airline carry-on rules for volumes over 100ml. Verify local regulatory status before international travel.
Dosing per SmPC and BNF.
Food: Must be taken on an empty stomach at least 30 minutes before food, or 2 hours after food. Absorption significantly reduced if taken with or after food. [SmPC] Athlete meal timing and training schedule should be considered when planning dosing times.
Supplement timing: No separation required from iron, calcium, magnesium, zinc, or dairy.
GI side effects: Generally well tolerated. Nausea reported but mild relative to other penicillins and to other antibiotic classes. Lowest GI burden within the penicillin class.
AAD risk: Low. Narrow spectrum means minimal gut flora disruption and very low diarrhoea risk.
Food restriction: Requirement to take on an empty stomach may require practical adjustment to training and meal schedules during treatment course.
Photosensitivity: Not a concern. No outdoor training restrictions required.
GI tolerability: Best tolerated penicillin within this class. GI side effects unlikely to significantly affect recovery capacity in most athletes on standard courses.
Microbiome disruption: Low. Narrow spectrum means gut flora largely unaffected. Probiotic consideration not routinely required.
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc, and multivitamins: No clinically significant absorption interaction established for phenoxymethylpenicillin.
Methotrexate: Phenoxymethylpenicillin may reduce renal excretion of methotrexate, increasing toxicity risk. [SmPC]
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.05 per 250mg tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
INDIVIDUAL AGENTS
Licensed indications include: Respiratory tract infections, skin and soft tissue infections, acne vulgaris, Lyme disease, some sexually transmitted infections, and malaria prophylaxis.
Photosensitivity: High risk within this class. Phototoxic reactions reported including severe sunburn and skin blistering. Directly relevant to outdoor athletes. Sun protection and protective clothing essential during treatment course and for a period after stopping.
Microbiome impact: Moderate. Marked short-term decrease in Bifidobacterium diversity reported. 6
AAD risk: Moderate.
Food interaction: Absorption not significantly affected by food or milk per SmPC. Taking with food or milk recommended if gastric irritation occurs.
Form: Capsules (50mg, 100mg). Modified-release capsules (40mg, Efracea). Dispersible tablets (100mg, Vibramycin-D).
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label. Verify local regulatory status before international travel.
SmPC: Doxycycline SmPC ↗
Dosing per SmPC and BNF.
Food: Absorption not significantly affected by food or milk. Taking with food or milk recommended if gastric irritation occurs. Avoid dairy and calcium-fortified foods at time of dosing where absorption optimisation is a priority.
Administration: Swallow capsules with plenty of water in a sitting or standing position. Take well before retiring at night to reduce the risk of oesophageal irritation and ulceration. [SmPC]
Outdoor training and photosensitivity: Avoid prolonged sun exposure during treatment course and for a period after stopping. Sun protection and protective clothing essential for all outdoor training and competition.
Photosensitivity: High risk. Phototoxic reactions including severe sunburn and skin blistering reported. Sun protection and protective clothing essential for outdoor training and competition during treatment course.
GI side effects: Nausea and oesophageal irritation reported. Taking with food and remaining upright after dosing recommended during training periods.
AAD risk: Moderate. GI side effects may affect hydration, electrolyte balance, and training nutrition during treatment course.
GI tolerability: Generally well tolerated when taken with food. GI side effects may affect training nutrition and hydration targets during treatment course.
Microbiome disruption: Moderate. Marked short-term decrease in Bifidobacterium diversity reported. Probiotic consideration may be appropriate. See TAF Probiotics entry. 6
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
Calcium, iron, magnesium, zinc, and multivitamins: Reduce doxycycline absorption via chelation. Separate dosing by at least two hours before or six hours after doxycycline dose.
Dairy and calcium-fortified foods and drinks: Reduce absorption. Where a meal contains dairy or fortified products, take at least two hours before or six hours after.
Retinoids and high-dose vitamin A: Concurrent use should be avoided. Risk of benign intracranial hypertension. [SmPC]
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.09 per 100mg capsule.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Acne vulgaris and other infections susceptible to tetracycline antibiotics.
Photosensitivity: Moderate risk within this class. Lower photosensitivity signal than doxycycline but still relevant for outdoor athletes. Sun protection advisable during treatment course.
Microbiome impact: Low to moderate. Less well characterised than doxycycline in available evidence.
AAD risk: Low to moderate.
Long-term use: Prolonged use increases cumulative microbiome disruption and photosensitivity exposure risk. Worth noting in athletes on extended courses.
Form: Capsules (408mg).
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label. Verify local regulatory status before international travel.
SmPC: Lymecycline SmPC ↗
Dosing per SmPC and BNF.
Food: No specific food guidance in SmPC. Avoid dairy and calcium-fortified foods at time of dosing due to chelation and absorption reduction.
Administration: Swallow capsules with plenty of water in a sitting or standing position. Take well before retiring at night to reduce the risk of oesophageal irritation and ulceration. [SmPC]
Outdoor training and photosensitivity: Avoid prolonged sun exposure during treatment course. Sun protection and protective clothing advisable for outdoor training and competition.
Photosensitivity: Moderate risk. Sun protection advisable for outdoor training and competition during treatment course.
GI side effects: Nausea and GI disturbance reported. Ensure adequate fluid intake when dosing. Remaining upright after dosing recommended during training periods.
AAD risk: Low to moderate. GI side effects may affect hydration and training nutrition during treatment course.
Long-term use: Extended courses for acne increase cumulative photosensitivity exposure and microbiome disruption risk.
GI tolerability: Generally well tolerated. GI side effects may affect training nutrition and hydration targets during treatment course.
Microbiome disruption: Low to moderate. Less well characterised than doxycycline. Probiotic consideration may be appropriate for extended courses. See TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
Calcium, iron, magnesium, zinc, and multivitamins: Reduce lymecycline absorption via chelation. Separate dosing by at least two hours before or six hours after lymecycline dose.
Dairy and calcium-fortified foods and drinks: Reduce absorption. Where a meal contains dairy or fortified products, take at least two hours before or six hours after.
Retinoids and high-dose vitamin A: Concurrent use should be avoided. Risk of benign intracranial hypertension. Particularly relevant given lymecycline is commonly co-prescribed with topical retinoids for acne. [SmPC]
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.13 per 408mg capsule.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Acne vulgaris.
CNS effects: Dizziness commonly reported. Vertigo and tinnitus reported less frequently. May affect balance, coordination, and training performance. Symptoms typically resolve on stopping treatment but warrant clinical review if persistent.
Hyperpigmentation: Reported at various body sites including skin, nails, teeth, and oral mucosa. May develop regardless of dose or duration but more common with long-term use. May persist after stopping treatment. [SmPC]
Photosensitivity: Lower risk than doxycycline within this class. Sun protection still advisable for outdoor athletes.
Microbiome impact: Low to moderate. Less well characterised than doxycycline in available evidence.
AAD risk: Low to moderate.
Long-term use: Prolonged use increases cumulative microbiome disruption risk and is associated with rare but serious adverse effects including drug-induced lupus and hepatotoxicity. Clinical monitoring recommended at three-monthly intervals where treatment exceeds six months. [SmPC]
Form: Modified-release capsules (100mg).
Route: Oral
Travel: No restrictions. Carry original packaging with dispensing label. Verify local regulatory status before international travel.
SmPC: Minocycline SmPC ↗
Dosing per SmPC and BNF.
Food: Absorption not significantly impaired by food or moderate amounts of milk. Taking with food recommended to reduce GI side effects during training.
Administration: Swallow capsules with plenty of fluid in a sitting or standing position. Take well before retiring at night to reduce the risk of oesophageal irritation and ulceration. [SmPC]
Supplement timing: Iron, calcium, magnesium, aluminium, bismuth, and zinc salts reduce minocycline absorption. Separate dosing by at least three hours before or after minocycline dose. [SmPC]
Outdoor training and photosensitivity: Photosensitivity risk lower than doxycycline but sun protection still advisable for outdoor training and competition.
CNS effects: Dizziness commonly reported. Vertigo and tinnitus reported less frequently. May affect balance, coordination, and training performance during treatment course.
Photosensitivity: Lower risk than doxycycline within this class. Sun protection advisable for outdoor training and competition.
GI side effects: Nausea and GI disturbance reported. Taking with food recommended during training periods.
AAD risk: Low to moderate. GI side effects may affect hydration and training nutrition during treatment course.
Long-term use: Extended courses for acne associated with rare but serious adverse effects. See Field 1.
CNS effects: Dizziness and vertigo may affect sleep quality and recovery during treatment course.
GI tolerability: Generally well tolerated. GI side effects may affect training nutrition and hydration targets during treatment course.
Microbiome disruption: Low to moderate. Probiotic consideration may be appropriate for extended courses. See TAF Probiotics entry.
Selected interactions relevant to common athlete use patterns. Not exhaustive. See SmPC for full interaction profile.
Iron, calcium, magnesium, zinc, aluminium, bismuth, and multivitamins: Reduce minocycline absorption. Separate dosing by at least three hours before or after minocycline dose. [SmPC]
Dairy and calcium-fortified foods and drinks: Absorption not significantly impaired by moderate amounts of milk per SmPC. Standard caution applies for calcium-fortified products.
Isotretinoin: Avoid concurrent use and for a period shortly before and after minocycline therapy. Each drug independently associated with benign intracranial hypertension. [SmPC]
Retinoids and high-dose vitamin A: Concurrent use should be avoided. Risk of benign intracranial hypertension. [SmPC]
Oral contraceptives: Minocycline may reduce efficacy of oral contraceptives. [SmPC]
Penicillins: Tetracyclines may interfere with the bactericidal action of penicillins. Avoid concurrent use. [SmPC]
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.36 per 100mg modified-release capsule.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com
Licensed indications include: Urinary tract infections and respiratory tract infections caused by susceptible organisms.
Folate antagonism: Trimethoprim reduces folic acid (folate) availability. In athletes with marginal folate status, including those with restrictive dietary intake or in a RED-S context, this warrants clinical consideration. Also relevant where trimethoprim is prescribed to female athletes who may be or become pregnant.
Microbiome impact: Low. Narrow spectrum limits gut flora disruption.
AAD risk: Low.
Photosensitivity: Mild signal. Relevant for prolonged outdoor training or competition during treatment course. Sun protection advisable.
Form: Tablets (100mg, 200mg). Oral suspension available.
Route: Oral
Travel: Tablets — no restrictions. Carry original packaging with dispensing label.
Oral suspensions — check airline carry-on rules for volumes over 100ml. Verify local regulatory status before international travel.
SmPC: Trimethoprim SmPC ↗
Dosing per SmPC and BNF.
Food: Can be taken with or without food. Taking with food recommended to minimise GI side effects during training.
Outdoor training and photosensitivity: Sun protection advisable during prolonged outdoor training or competition during treatment course.
GI side effects: Nausea and vomiting reported but generally mild. Taking with food recommended during training periods.
AAD risk: Low. Narrow spectrum limits gut flora disruption and associated diarrhoea risk.
Photosensitivity: Mild signal. Sun protection advisable for outdoor training and competition during treatment course.
Folate availability: Reduced folate availability during treatment course may be relevant in athletes with marginal dietary folate intake.
GI tolerability: Generally well tolerated. GI side effects unlikely to significantly affect recovery capacity in most athletes on standard short courses.
Microbiome disruption: Low. Narrow spectrum means gut flora largely unaffected. Probiotic consideration not routinely required.
Selected interactions relevant to common athlete use patterns. Not exhaustive — see SmPC for full interaction profile.
Folate supplements: Athletes taking folate or multivitamins containing folate should be aware that trimethoprim reduces folate availability.
NSAIDs: No direct pharmacokinetic interaction. Concurrent use may compound GI side effects during treatment course.
Iron, calcium, magnesium, zinc: No clinically significant absorption interaction established for trimethoprim.
WADA: Not Prohibited 2026.
POM in the UK. Prescription required.
Regulatory and licensing status may vary by jurisdiction. Verify local requirements before international travel or competition.
Approximately £0.27 per 200mg tablet.
Verify current pricing at bnf.nice.org.uk.
Excipients vary by manufacturer. Verify per dispensed product.
Vegetarian: Verify per dispensed product.
Vegan: Verify per dispensed product.
Halal: Verify per dispensed product.
Kosher: Verify per dispensed product.
For product-specific allergen or excipient queries, contact info@medsontrack.com