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Drugs reference index «Rifampin»


Pronunciation: (RIFF-am-pin)Class: Antituberculosis agent

Trade Names:Rifadin- Capsules 150 mg- Capsules 300 mg- Powder for injection 600 mg

Trade Names:Rimactane- Capsules 300 mg

Rofact (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).

Indications and Usage

Adjunctive treatment of tuberculosis; short-term management to eliminate meningococci from nasopharynx in Neisseria meningitidis carriers.

Unlabeled Uses

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.

Dosage and Administration


IV dosage form is for initial treatment or retreatment when drug cannot be taken by mouth.


PO/IV 10 mg/kg/day (max, 600 mg/day) or 10 mg/kg 2 or 3 times/wk (max, 600 mg).


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.

Drug Interactions

Azole antifungal agents, benzodiazepines, beta-blockers, buspirone, chloramphenicol, clarithromycin, clozapine, oral contraceptives, corticosteroids, cyclosporine, delavirdine, digitoxin, disopyramide, doxycycline, erythromycin, estrogens, haloperidol, hydantoins, indinavir, losartan, methadone, mexiletine, morphine, nelfinavir, ondansetron, oral anticoagulants, quinidine, quinine, ritonavir, sulfonylureas, tacrolimus, tamoxifen, theophyllines, tocainide, toremifene, tricyclic antidepressants, troleandomycin, verapamil, zolpidem

Therapeutic efficacy may be decreased because of liver enzyme-inducing properties of rifampin.


May decrease digoxin serum concentrations.


May significantly increase BP.


Hepatotoxicity and hepatic encephalopathy have been reported with coadministration.


May result in higher rate of hepatotoxicity.


May cause treatment failure of either ketoconazole or rifampin.


Elevates rifampin levels.

Laboratory Test Interactions

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.

Adverse Reactions


Hypotension; shock.


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.

Hepatic Function

Dosage adjustment is necessary.

Body fluids

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.

Patient Information

  • Instruct patient to take drug on empty stomach, 1 h before or 2 h after meals.
  • Inform patient that body fluids may turn red-orange in color and that soft contact lenses may become permanently stained. Advise patient to wear glasses during course of therapy.
  • Instruct patient to notify health care provider of persistent anorexia, nausea, vomiting, diarrhea, jaundice, fever, change in color or consistency of stools, malaise or right upper quadrant abdominal pain, unusual bleeding or bruising, petechiae, hematuria, bleeding gums, or pallor.
  • Tell patient to notify health care provider of drowsiness, fatigue, dizziness, inability to concentrate, confusion, or visual or behavioral changes.
  • Advise patient who uses oral contraceptives to use nonhormonal form of contraception during therapy.
  • Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.
  • Advise patient of importance of medication compliance in treatment of tuberculosis. Medication noncompliance reduces efficacy and promotes resistance.
  • Caution patient to avoid alcohol.

Copyright © 2009 Wolters Kluwer Health.

  • Rifampin Injection Prescribing Information (FDA)
  • Rifampin MedFacts Consumer Leaflet (Wolters Kluwer)
  • rifampin Concise Consumer Information (Cerner Multum)
  • rifampin Oral, Intravenous Advanced Consumer (Micromedex) - Includes Dosage Information
  • Rifadin MedFacts Consumer Leaflet (Wolters Kluwer)
  • Rifadin Prescribing Information (FDA)

See Also...

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