Comparative Pharmacology
Head-to-head clinical analysis: SULFAPYRIDINE versus TRIMETH SULFA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SULFAPYRIDINE versus TRIMETH SULFA.
SULFAPYRIDINE vs TRIMETH/SULFA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Sulfapyridine is a sulfonamide antibiotic that inhibits bacterial dihydropteroate synthase, blocking folate synthesis and thereby nucleic acid production. It also has anti-inflammatory and immunomodulatory effects in dermatologic conditions through unknown mechanisms.
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.
500 mg orally four times daily for initial treatment of dermatitis herpetiformis; maintenance dose 500 mg daily to 1.5 g daily in divided doses.
1 double-strength tablet (160 mg trimethoprim / 800 mg sulfamethoxazole) orally every 12 hours for 14 days.
None Documented
None Documented
Clinical Note
moderateSulfapyridine + Mecamylamine
"The risk or severity of adverse effects can be increased when Sulfapyridine is combined with Mecamylamine."
Clinical Note
moderateDexketoprofen + Sulfapyridine
"The risk or severity of adverse effects can be increased when Dexketoprofen is combined with Sulfapyridine."
Terminal elimination half-life: 6–10 hours (prolonged in renal impairment or slow acetylators); clinical context: requires dosing adjustment in renal insufficiency.
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.
Renal: approximately 70–80% (30% as unchanged drug, remainder as metabolites, primarily N4-acetylsulfapyridine); biliary/fecal: minor (<5%).
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.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic