Trade Names:Rifadin- Capsules 150 mg- Capsules 300 mg- Powder for injection 600 mg
Trade Names:Rimactane- Capsules 300 mgRofact (Canada)
Inhibits DNA-dependent RNA polymerase in susceptible strains of bacteria.
Almost completely absorbed (oral). T max is 1 to 4 h (oral). C max is 7 mcg/mL (oral average), may vary 4 to 32 mcg/mL (oral adults); 3.5 to 15 mcg/mL (oral, children); 9 to 17 mcg/mL (IV). Absorption decreased 30% when taken with food.
Vd is about 0.64 L/kg (600 mg IV); 0.66 L/kg (300 mg IV). Diffuses well into most body tissues and fluids, including CSF. Crosses placenta and distributes into breast milk. Protein binding is 89%.
Metabolized in liver by deacetylation to active metabolite 25-0-desacetylrifampin. Undergoes enterohepatic circulation.
Primarily through bile/fecal (60% to 65% in feces); renal (6% to 15% excreted as unchanged, 15% excreted as active metabolites, 7% as inactive metabolites).
Adjunctive treatment of tuberculosis; short-term management to eliminate meningococci from nasopharynx in Neisseria meningitidis carriers.
Treatment of infections caused by Staphylococcus aureus and Staphylococcus epidermidis ; treatment of gram-negative bacteremia in infancy; treatment of Legionella ; management of leprosy; prophylaxis of Haemophilus influenzae meningitis.
Hypersensitivity to any rifamycin.
IV dosage form is for initial treatment or retreatment when drug cannot be taken by mouth.Adults
PO/IV 10 mg/kg/day (max, 600 mg/day) or 10 mg/kg 2 or 3 times/wk (max, 600 mg).Children
PO/IV 10 to 20 mg/kg/day (max, 600 mg/day) or 10 to 20 mg/kg 2 to 3 times/wk (max, 600 mg).Meningococcal CarriersAdults
PO/IV 600 mg every day for 4 consecutive days.Children 1 mo or older
PO/IV 10 mg/kg every 12 h for 2 consecutive days.Children younger than 1 mo
5 mg/kg every 12 h for 2 consecutive days.
Therapeutic efficacy may be decreased because of liver enzyme-inducing properties of rifampin.Digoxin
May decrease digoxin serum concentrations.Enalapril
May significantly increase BP.Halothane
Hepatotoxicity and hepatic encephalopathy have been reported with coadministration.Isoniazid
May result in higher rate of hepatotoxicity.Ketoconazole
May cause treatment failure of either ketoconazole or rifampin.Probenecid
Elevates rifampin levels.
May inhibit standard microbiological assays for serum folate and vitamin B 12 . Thus, use alternate assay methods. Transient abnormalities in LFTs (eg, elevation in serum bilirubin, abnormal bromsulfophthalein excretion, alkaline phosphatase, serum transaminases) and reduced biliary excretion of contrast media used for visualization of gallbladder may occur. Therefore, perform these tests before the morning dose of rifampin.
Headache; drowsiness; fatigue; dizziness; inability to concentrate; mental confusion; generalized numbness; behavioral changes; myopathy.
Rash; pruritus; urticaria; pemphigoid reaction; flushing.
Visual disturbances; exudative conjunctivitis.
Heartburn; epigastric distress; anorexia; nausea; vomiting; gas; cramps; diarrhea; sore mouth and tongue; pseudomembranous colitis; pancreatitis.
Hemoglobinuria; hematuria; renal insufficiency; acute renal failure.
Eosinophilia; transient leukopenia; hemolytic anemia; decreased hemoglobin; hemolysis; thrombocytopenia.
Asymptomatic elevations of liver enzymes and hepatitis.
Shortness of breath; wheezing.
Ataxia; muscular weakness; pain in extremities; osteomalacia; myopathy; menstrual disturbances; fever; elevations in BUN; elevated serum uric acid; possible immunosuppression; abnormal growth of lung tumors; reduced 25-hydroxycholecalciferol levels; edema of face and extremities; discoloration of body fluids.
Category C .
Excreted in breast milk. Discontinue nursing or drug.
Dosage adjustment is necessary.
Medication may cause harmless red-orange discoloration of urine, feces, saliva, sputum, sweat, and tears. Soft contact lenses may be permanently stained.
Nausea, vomiting, increasing lethargy, unconsciousness, liver enlargement, jaundice, increased direct and total bilirubin levels, altered hepatic enzyme levels.
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