Comparative Pharmacology
Head-to-head clinical analysis: COTRIM D S versus FOSFOMYCIN TROMETHAMINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: COTRIM D S versus FOSFOMYCIN TROMETHAMINE.
COTRIM D.S. vs FOSFOMYCIN TROMETHAMINE
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.
Fosfomycin inhibits bacterial cell wall synthesis by inactivating the enzyme UDP-N-acetylglucosamine enolpyruvyl transferase (MurA), which catalyzes the first step of peptidoglycan biosynthesis.
160 mg trimethoprim / 800 mg sulfamethoxazole (one double-strength tablet) orally every 12 hours.
3 g orally once as a single dose for uncomplicated urinary tract infection.
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 5.7 hours (range 3-8 hours) in patients with normal renal function; approximately 50 hours in end-stage renal disease (CrCl <10 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%.
Primarily excreted unchanged in urine via glomerular filtration (approximately 90% of absorbed dose within 24-48 hours); small amount (approximately 10%) excreted in feces via biliary elimination.
Category C
Category A/B
Antibiotic
Antibiotic