Overview
DESCRIPTION RIFADIN (rifampin capsules USP) for oral administration contains 150 mg or 300 mg rifampin per capsule. The 150 mg and 300 mg capsules also contain, as inactive ingredients: corn starch, D&C Red No. 28, FD&C Blue No. 1, FD&C Red No. 40, gelatin, magnesium stearate, and titanium dioxide.
Mechanism of Action
CLINICAL PHARMACOLOGY Oral Administration Rifampin is readily absorbed from the gastrointestinal tract. Peak serum concentrations in healthy adults and pediatric populations vary widely from individual to individual. Following a single 600 mg oral dose of rifampin in healthy adults, the peak serum concentration averages 7 mcg/mL but may vary from 4 to 32 mcg/mL. Absorption of rifampin is reduced by about 30% when the drug is ingested with food. Rifampin is widely distributed throughout the body. It is present in effective concentrations in many organs and body fluids, including cerebrospinal fluid. Rifampin is about 80% protein bound. Most of the unbound fraction is not ionized and, therefore, diffuses freely into tissues.
Indications
- INDICATIONS AND USAGE In the treatment of both tuberculosis and the meningococcal carrier state, the small number of resistant cells present within large populations of susceptible cells can rapidly become the predominant type. Bacteriologic cultures should be obtained before the start of therapy to confirm the susceptibility of the organism to rifampin and they should be repeated throughout therapy to monitor the response to treatment. Since resistance can emerge rapidly, susceptibility tests should be performed in the event of persistent positive cultures during the course of treatment.
Common Doses
- 10 mg
- 600 mg
- 20 mg
- 10 mL
Dosage
DOSAGE AND ADMINISTRATION Rifampin can be administered by the oral route or by IV infusion (see INDICATIONS AND USAGE ). IV doses are the same as those for oral. See CLINICAL PHARMACOLOGY for dosing information in patients with renal failure. Tuberculosis Adults: 10 mg/kg, in a single daily administration, not to exceed 600 mg/day, oral or IV Pediatric Patients: 10–20 mg/kg, not to exceed 600 mg/day, oral or IV It is recommended that oral rifampin be administered once daily, either 1 hour before or 2 hours after a meal with a full glass of water.
Contraindications
- CONTRAINDICATIONS RIFADIN is contraindicated in patients with a history of hypersensitivity to rifampin or any of the components, or to any of the rifamycins. (See WARNINGS .) Rifampin is contraindicated in patients who are also receiving ritonavir-boosted saquinavir due to an increased risk of severe hepatocellular toxicity. (See PRECAUTIONS, Drug Interactions .) Rifampin is contraindicated in patients who are also receiving atazanavir, darunavir, fosamprenavir, saquinavir, tipranavir, cabotegravir, fostemsavir and lenacapavir (see prescribing information for SUNLENCA ® ) due to the...
Side Effects
- ADVERSE REACTIONS The following adverse reactions associated with the use of RIFADIN were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Gastrointestinal Heartburn, epigastric distress, anorexia, nausea, vomiting, jaundice, flatulence, cramps, and diarrhea have been noted in some patients.
Interactions
- Drug Interactions Pharmacodynamic Interactions Healthy subjects who received rifampin 600 mg once daily concomitantly with saquinavir 1000 mg/ritonavir 100 mg twice daily (ritonavir-boosted saquinavir) developed severe hepatocellular toxicity. Therefore, concomitant use of these medications is contraindicated. (See CONTRAINDICATIONS .) When rifampin is given concomitantly with other hepatotoxic medications such as halothane or isoniazid, the potential for hepatotoxicity is increased. The concomitant use of rifampin and halothane should be avoided.