Comparative Pharmacology
Head-to-head clinical analysis: TRIMETHOPRIM SULFATE AND POLYMYXIN B SULFATE versus XIFAXAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TRIMETHOPRIM SULFATE AND POLYMYXIN B SULFATE versus XIFAXAN.
TRIMETHOPRIM SULFATE AND POLYMYXIN B SULFATE vs XIFAXAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Trimethoprim inhibits bacterial dihydrofolate reductase, blocking tetrahydrofolate synthesis and thereby inhibiting thymidine synthesis. Polymyxin B disrupts bacterial cell membrane integrity by binding to lipopolysaccharides in Gram-negative bacteria.
Rifaximin is a non-systemic, gut-selective antibiotic that inhibits bacterial RNA synthesis by binding to the beta-subunit of bacterial DNA-dependent RNA polymerase, thereby reducing bacterial overgrowth and altering gut microbiota composition.
One drop in each affected eye every 2 to 4 hours for 7 to 10 days.
550 mg orally twice daily for traveler's diarrhea; 550 mg orally three times daily for hepatic encephalopathy.
None Documented
None Documented
Trimethoprim: 8-10 hours (normal renal function); Polymyxin B: 6 hours (prolonged in renal impairment).
The terminal elimination half-life for rifaximin after oral administration ranges from 1.8 to 10 hours, with a mean of approximately 6 hours. The half-life is extended in hepatic impairment due to reduced clearance, and no dosage adjustment is recommended for renal impairment.
Trimethoprim: renal (80-90% unchanged, 10-20% metabolites); Polymyxin B: renal (60% unchanged, 40% nonrenal).
Rifaximin is primarily eliminated unchanged in feces via biliary excretion (approximately 97% of an oral dose). Renal excretion of unchanged drug accounts for <0.4% of the dose. Fecal elimination is the major route.
Category D/X
Category C
Antibiotic
Antibiotic