Comparative Pharmacology
Head-to-head clinical analysis: COTRIM D S versus MYCHEL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: COTRIM D S versus MYCHEL.
COTRIM D.S. vs MYCHEL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
COTRIM D.S. is a combination of sulfamethoxazole, a competitive inhibitor of dihydropteroate synthase, and trimethoprim, a reversible inhibitor of dihydrofolate reductase. This sequential blockade of folate synthesis leads to bactericidal activity.
Mychel is a topical antifungal agent that inhibits ergosterol synthesis by binding to fungal cytochrome P450 14α-demethylase, disrupting fungal cell membrane integrity.
160 mg trimethoprim / 800 mg sulfamethoxazole (one double-strength tablet) orally every 12 hours.
Adults: 200 mg orally twice daily for 14 days.
None Documented
None Documented
Sulfamethoxazole: 9-12 hours (normal renal function). Trimethoprim: 8-11 hours. Both are prolonged in renal impairment (e.g., creatinine clearance <30 mL/min: >24 hours). Clinical context: dosing interval is typically 12 hours; dose adjustment required if CrCl <30 mL/min.
Terminal half-life: 8.5-12 hours (mean 10.2 h) in normal renal function; prolonged to 18-30 h in severe renal impairment (CrCl <30 mL/min)
Sulfamethoxazole: ~20% unchanged in urine, remainder as acetylated and glucuronide metabolites. Trimethoprim: ~50-80% unchanged in urine, remainder as oxidative metabolites. Both undergo renal excretion via glomerular filtration and tubular secretion. Total renal elimination: 70-90% of dose combined. Biliary/fecal: <10%.
Renal: ~70% unchanged; fecal: ~15% as metabolites; biliary: ~10%
Category C
Category C
Antibiotic
Antibiotic