Pregnancy Risk Category C
How supplied
Capsules: 150 mg, 300 mg
Injection: 600 mg
Action
Inhibits DNA-dependent RNA polymerase, thus impairing RNA synthesis (bactericidal).
Indications & dosage
Pulmonary tuberculosis-
Adults: 600 mg P.O. or I.V. daily in single dose 1 hour before or 2 hours after meals.
Children over age 5: 10 to 20 mg/kg P.O. or I.V. daily in single dose 1 hour before or 2 hours after meals. Maximum daily dose is 600 mg. Administration with other antituberculotics is recommended.
Meningococcal carriers-
Adults: 600 mg P.O. or I.V. q 12 hours for 2 days; or 600 mg P.O. or I.V. once daily for 4 days.
Children ages 1 month to 12 years: 10 mg/kg P.O. or I.V. q 12 hours for 2 days, not to exceed 600 mg/day; or 20 mg/kg once daily for 4 days.
Neonates: 5 mg/kg P.O. or I.V. q 12 hours for 2 days.
Adverse reactions
CNS: headache, fatigue, drowsiness, behavioral changes, dizziness, mental confusion, generalized numbness, ataxia.
CV: shock.
EENT: visual disturbances, exudative conjunctivitis.
GI: epigastric distress, anorexia, nausea, vomiting, abdominal pain, diarrhea, flatulence, sore mouth and tongue, pseudomembranous colitis, pancreatitis.
GU: hemoglobinuria, hematuria, acute renal failure, menstrual disturbances.
Hematologic: eosinophilia, thrombocytopenia, transient leukopenia, hemolytic anemia.
Hepatic: hepatotoxicity, transient abnormalities in liver function tests.
Musculoskeletal: osteomalacia.
Respiratory: shortness of breath, wheezing.
Skin: pruritus, urticaria, rash.
Other: flulike syndrome, discoloration of body fluids, hyperuricemia, porphyria exacerbation.
Interactions
Drug-drug. Acetaminophen, analgesics, anticoagulants, anticonvulsants, barbiturates, beta blockers, cardiac glycosides, clofibrate, chloramphenicol, corticosteroids, cyclosporine, dapsone, diazepam, disopyramide, methadone, mexiletine, narcotics, oral contraceptives, progestins, quinidine, sulfonylureas, theophylline, verapamil: reduced effectiveness of these drugs. Monitor closely.
Halothane: may increase risk of hepatotoxicity of both drugs. Monitor liver function closely.
Ketoconazole, para-aminosalicylate sodium: may interfere with absorption of rifampin. Give these drugs 8 to 12 hours apart.
Probenecid: may increase rifampin levels. Use cautiously.
Drug-lifestyle. Alcohol use: may increase risk of hepatotoxicity. Avoid use of alcohol during therapy.
Effects on diagnostic tests
Rifampin alters standard serum folate and vitamin B12 assays. Rifampin may cause temporary retention of sulfobromophthalein in the liver excretion test. It may also interfere with contrast material in gallbladder studies and urinalysis based on spectrophotometry.
Contraindications
Contraindicated in patients with hypersensitivity to rifampin or related drugs.
Nursing considerations
I.V. administration
Patient teaching
*Liquid contains alcohol. **May contain tartrazine. †Canada ‡Australia §U.K. OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING