Comparative Pharmacology
Head-to-head clinical analysis: COTRIM D S versus TRIMPEX 200.
Peer-Reviewed Evidence
Head-to-head clinical analysis: COTRIM D S versus TRIMPEX 200.
COTRIM D.S. vs TRIMPEX 200
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.
Trimethoprim inhibits bacterial dihydrofolate reductase, blocking the conversion of dihydrofolic acid to tetrahydrofolic acid, thereby inhibiting bacterial DNA synthesis.
160 mg trimethoprim / 800 mg sulfamethoxazole (one double-strength tablet) orally every 12 hours.
200 mg orally once daily, or 100 mg orally twice daily.
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 elimination half-life is 8-10 hours in adults with normal renal function; prolonged to 20-30 hours in renal impairment (CrCl <30 mL/min), requiring dose adjustment.
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 excretion of unchanged drug accounts for approximately 60-80% of elimination, with an additional 10-20% as hepatic metabolites excreted in bile and feces.
Category C
Category C
Antibiotic
Antibiotic