Comparative Pharmacology
Head-to-head clinical analysis: TRIMETH SULFA versus TRIPLE SULFA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TRIMETH SULFA versus TRIPLE SULFA.
TRIMETH/SULFA vs TRIPLE SULFA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Trimethoprim inhibits bacterial dihydrofolate reductase (DHFR), blocking conversion of dihydrofolate to tetrahydrofolate; sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking incorporation of para-aminobenzoic acid into folic acid. Sequential blockade of folate synthesis produces synergistic bactericidal effect.
Inhibits bacterial dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR), blocking folate synthesis essential for nucleic acid production.
1 double-strength tablet (160 mg trimethoprim / 800 mg sulfamethoxazole) orally every 12 hours for 14 days.
1 g orally every 12 hours for 10 days (as sulfadiazine, sulfamethazine, and sulfamerazine combination).
None Documented
None Documented
Trimethoprim: 8-11 hours; Sulfamethoxazole: 9-11 hours. Prolonged in renal impairment (up to 24-30 hours for both). Clinical context: Dosing interval is typically 12 hours in normal renal function; adjust in CrCl <15-30 mL/min.
6-12 hours (sulfadiazine 10-13h, sulfamerazine 16-24h, sulfamethazine 7-12h); prolonged in renal impairment.
Trimethoprim: 50-60% unchanged in urine; Sulfamethoxazole: 15-30% unchanged in urine, with acetylation and glucuronidation metabolites. Approximately 80-90% of dose recovered in urine within 72 hours; remainder via feces.
80-90% renal (glomerular filtration and tubular secretion) as unchanged drug and acetylated metabolites; 5-10% biliary/fecal.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic