Comparative Pharmacology
Head-to-head clinical analysis: BACTRIM versus BACTRIM DS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BACTRIM versus BACTRIM DS.
BACTRIM vs BACTRIM DS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
BACTRIM (sulfamethoxazole/trimethoprim) inhibits bacterial folate synthesis. Sulfamethoxazole, a sulfonamide, inhibits dihydropteroate synthase, blocking PABA incorporation into dihydrofolic acid. Trimethoprim inhibits dihydrofolate reductase, blocking conversion of dihydrofolic acid to tetrahydrofolic acid. Sequential blockade leads to bactericidal effect.
BACTRIM DS is a combination of sulfamethoxazole and trimethoprim. Sulfamethoxazole inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic acid (PABA), while trimethoprim inhibits dihydrofolate reductase, blocking reduction of dihydrofolate to tetrahydrofolate. This sequential blockade of folic acid synthesis leads to bactericidal action.
1 DS tablet (160 mg TMP/800 mg SMX) orally every 12 hours for 10-14 days.
One double-strength tablet (trimethoprim 160 mg-sulfamethoxazole 800 mg) orally every 12 hours.
None Documented
None Documented
Sulfamethoxazole: 9-12 hours (prolonged in renal impairment); Trimethoprim: 8-10 hours (prolonged in renal impairment).
Sulfamethoxazole: 8-10 hours; Trimethoprim: 8-12 hours; prolonged in renal impairment (creatinine clearance <30 mL/min: up to 24-48 hours).
Renal: sulfamethoxazole 20-30% unchanged, trimethoprim 40-70% unchanged; biliary/fecal: minimal (<10%) for both components.
Renal: 50-70% as sulfamethoxazole (unchanged and acetylated metabolite), 40-60% as trimethoprim (unchanged); biliary: <10% for both; fecal: <4%.
Category C
Category C
Sulfonamide Antibiotic Combination
Sulfonamide Antibiotic Combination