Comparative Pharmacology
Head-to-head clinical analysis: SEPTRA DS versus SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SEPTRA DS versus SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH.
SEPTRA DS vs SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
SEPTRA DS is a combination of trimethoprim and sulfamethoxazole. Trimethoprim inhibits bacterial dihydrofolate reductase, while sulfamethoxazole inhibits dihydropteroate synthase, sequentially blocking folate synthesis and ultimately DNA synthesis in susceptible bacteria.
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folate synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking tetrahydrofolate synthesis. Together, they provide sequential blockade of folate metabolism, leading to bactericidal activity.
One DS tablet (800 mg sulfamethoxazole/160 mg trimethoprim) orally every 12 hours for 10-14 days.
1 double-strength tablet (800 mg sulfamethoxazole/160 mg trimethoprim) orally every 12 hours for most infections; single-strength tablet (400 mg/80 mg) is used for prophylaxis: 1 tablet orally daily.
None Documented
None Documented
Trimethoprim: 8-10 hours; sulfamethoxazole: 10-12 hours (prolonged in renal impairment, e.g., creatinine clearance <30 mL/min increases half-life to >20 hours).
Sulfamethoxazole: 10-12 hours (prolonged in renal impairment); Trimethoprim: 8-11 hours (prolonged in hepatic impairment).
Renal excretion of unchanged drugs accounts for 50-70% of trimethoprim and 20-30% of sulfamethoxazole; biliary excretion is minor (<10% total).
Sulfamethoxazole: primarily renal (70-90% as unchanged drug and acetylated metabolite); Trimethoprim: renal (50-60% unchanged, rest as metabolites); small biliary/fecal elimination (<5% each).
Category C
Category D/X
Antibiotic
Antibiotic