Comparative Pharmacology
Head-to-head clinical analysis: COTRIM D S versus NITROFURANTOIN MONOHYDRATE MACROCRYSTALS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: COTRIM D S versus NITROFURANTOIN MONOHYDRATE MACROCRYSTALS.
COTRIM D.S. vs NITROFURANTOIN (MONOHYDRATE/MACROCRYSTALS)
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.
Nitrofurantoin is reduced by bacterial flavoproteins to reactive intermediates that inhibit bacterial cell wall synthesis, protein synthesis, and DNA/RNA synthesis. It is bacteriostatic at low concentrations and bactericidal at higher concentrations.
160 mg trimethoprim / 800 mg sulfamethoxazole (one double-strength tablet) orally every 12 hours.
100 mg orally twice daily for 5-7 days; 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: 20-60 minutes (average ~30 min) in patients with normal renal function; prolonged in renal impairment (e.g., CrCl <60 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 excretion of unchanged drug accounts for approximately 40% of the dose; tubular reabsorption occurs. Biliary/fecal elimination is minimal (<5%).
Category C
Category D/X
Antibiotic
Antibiotic