Comparative Pharmacology
Head-to-head clinical analysis: NITROFURANTOIN MACROCRYSTALLINE versus SEPTRA DS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NITROFURANTOIN MACROCRYSTALLINE versus SEPTRA DS.
NITROFURANTOIN MACROCRYSTALLINE vs SEPTRA DS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Nitrofurantoin is reduced by bacterial flavoproteins to reactive intermediates that inhibit multiple bacterial enzymes involved in carbohydrate metabolism, including acetyl-CoA synthetase, and disrupt cell wall synthesis.
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.
100 mg orally twice daily for 5-7 days (uncomplicated UTI); 100 mg orally every 12 hours for 10-14 days (pyelonephritis: not first-line).
One DS tablet (800 mg sulfamethoxazole/160 mg trimethoprim) orally every 12 hours for 10-14 days.
None Documented
None Documented
Terminal half-life: 20-60 minutes (short, requires q6h dosing for therapeutic efficacy).
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).
Renal: 30-40% excreted unchanged in urine. Biliary/fecal: minimal; remainder metabolized or eliminated via other routes.
Renal excretion of unchanged drugs accounts for 50-70% of trimethoprim and 20-30% of sulfamethoxazole; biliary excretion is minor (<10% total).
Category D/X
Category C
Antibiotic
Antibiotic