Rifaximin (CAS 80621-81-4) Suppliers and Product Information

Rifaximin is a semisynthetic, non-absorbable antibiotic derived from rifamycin. It is used for treating gastrointestinal infections, traveler's diarrhea, and hepatic encephalopathy. Rifaximin is effective against both Gram-positive and Gram-negative aerobic and anaerobic bacteria, including Salmonella spp., S. aureus, and E. coli.

Frequently Asked Questions about Rifaximin

What is the mechanism of action of Rifaximin?

Rifaximin acts on the β subunit of the DNA-dependent RNA polymerase enzyme in bacteria, inhibiting bacterial RNA synthesis. It is more effective against Gram-positive organisms compared to Gram-negative ones.

What are the clinical uses of Rifaximin?

Rifaximin is used for various gastrointestinal diseases, including traveler's diarrhea. It has shown efficacy in treating hepatic encephalopathy and C. difficile infections.

What are the side effects of Rifaximin?

Rifaximin has few reported adverse effects, mostly gastrointestinal discomfort. Prolonged therapy has been associated with infrequent urticarial skin reactions. It is classified as pregnancy category C due to reported teratogenic effects in rats and rabbits.

How does Rifaximin interact with other drugs?

Rifaximin may potentially increase the concentration of ciclosporin when used concurrently.

What is the pharmacokinetic profile of Rifaximin?

Oral absorption of Rifaximin is very low. A 400 mg oral dose produces a maximum plasma concentration of 3.8 mg/L after 1-2 hours. The plasma half-life is 5-8 hours. Up to 90% of the administered dose is concentrated in the gut, with minimal distribution to other tissues.