A medication used to prevent or treat tuberculosis.
Information about Rifampin
Liver safety of Rifampin
Rifampin is associated with transient and asymptomatic elevations in serum aminotransferase and bilirubin levels and is a well known cause of clinically apparent, acute liver disease that can be severe and even fatal.
Mechanism of action of Rifampin
Rifampin (rif am' pin) belongs to a class of medications know as rifamycins and is a synthetic derivative of natural products of the bacterium, S. mediterranei. Rifampin is a complex macrocyclic antibiotic that has activity against several bacteria, but most prominently inhibits growth of M. tuberculosis and several atypical mycobacterial species, probably as a result of inhibition of the DNA-dependent RNA polymerase of mycobacteria.
FDA approval information for Rifampin
Rifampin was approved for use in therapy of tuberculosis in the United States in 1971. Rifampin remains a mainstay of therapy of tuberculosis and atypical mycobacteria infections and is usually used in conjunction with isoniazid and/or pyrazinamide. Other approved uses of rifampin include chemoprophylaxis of meningococcal disease and meningitis due to H. influenza. Rifampin is used off-label as therapy of itching due to liver disease.
Dosage and administration for Rifampin
Rifampin is available in multiple generic forms and under the trade names of Rimactane and Rifadin in capsules of 150 and 300 mg. Pediatric formulations are available as well, as are powdered preparations for parenteral administration. The recommended dose for therapy of tuberculosis in adults is 600 mg (~10 mg/kg) daily and in children 10-20 mg/kg, but no more than 600 mg daily. Fixed combinations of rifampin (300 mg) with isoniazid (150 mg) are available under the brand name Rifamate, and combinations of rifampin (120 mg) with both isoniazid (50 mg) and pyrazinamide (300 mg) under the brand name Rifater.
Side effects of Rifampin
Side effects of rifampin are uncommon, but include rash, fever, flu-like symptoms, gastrointestinal upset and orange discoloration of urine and sweat. Rifampin is a potent inducer of many hepatic enzymes including the drug metabolizing enzymes, CYP 1A2, 2C9, 2C19 and 3A4 for which reason use of concurrent medications (such as oral contraceptives, anticoagulants, some antiretroviral agents, cyclosporine, benzodiazepines, and macrolide antibiotics) should be carefully chosen and monitored. Rifabutin and rifapentine are two other rifamycins that can be used in place of rifampin, rifabutin being useful if drug-interactions are an issue and rifapentine if once weekly dosing is preferred.
The following are list of antituberculosis medications that are discussed individually: