Comparative Pharmacology
Head-to-head clinical analysis: RIFAXIMIN versus SEPTRA GRAPE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: RIFAXIMIN versus SEPTRA GRAPE.
RIFAXIMIN vs SEPTRA GRAPE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Rifaximin is a non-aminoglycoside, semi-synthetic antibiotic derived from rifamycin that inhibits bacterial RNA synthesis by binding to the beta-subunit of bacterial DNA-dependent RNA polymerase, thereby blocking transcription.
Septra Grape (trimethoprim/sulfamethoxazole) inhibits bacterial folic acid synthesis via sequential blockade: sulfamethoxazole inhibits dihydropteroate synthase, and trimethoprim inhibits dihydrofolate reductase, leading to bactericidal activity.
550 mg orally three times daily for 14 days for travelers' diarrhea; 200 mg orally three times daily for 3 days for irritable bowel syndrome with diarrhea; 400 mg orally three times daily for 7 days for hepatic encephalopathy.
160 mg trimethoprim / 800 mg sulfamethoxazole (1 double-strength tablet) orally every 12 hours.
None Documented
None Documented
Clinical Note
moderateRifaximin + Digoxin
"The serum concentration of Digoxin can be increased when it is combined with Rifaximin."
Clinical Note
moderateRifaximin + Levofloxacin
"The serum concentration of Levofloxacin can be increased when it is combined with Rifaximin."
Clinical Note
moderateRifaximin + Estrone sulfate
"The serum concentration of Estrone sulfate can be decreased when it is combined with Rifaximin."
Clinical Note
moderateRifaximin + Tranilast
The terminal elimination half-life is approximately 1.8 to 2.5 hours in patients with normal hepatic function. Due to negligible systemic absorption, the half-life has limited clinical relevance; drug action is largely confined to the gastrointestinal tract.
Trimethoprim: 8-10 hours (renal impairment >24h). Sulfamethoxazole: 10-13 hours (acetylation phenotype; prolonged in renal impairment). Clinical: Dosing interval generally 12h; adjust CrCl <30 mL/min.
Rifaximin is primarily eliminated in feces as unchanged drug (>96% of an oral dose). Renal excretion is negligible (<0.4%). Biliary excretion is minimal due to poor systemic absorption.
Renal: 50-70% unchanged (trimethoprim), 30-50% as N-acetyl metabolite; sulfamethoxazole: 70-80% as metabolites, 20-30% unchanged; biliary excretion minimal (<5% total).
Category A/B
Category C
Antibiotic
Antibiotic
"The serum concentration of Tranilast can be decreased when it is combined with Rifaximin."