RIFAMPIN 
(rif'am-pin)
Rifadin, Rimactane, Rofact 
Classifications: antiinfective; antibiotic; antituberculosis agent
Pregnancy Category: C
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150 mg, 300 mg capsules; 600 mg injection
Semisynthetic derivative of rifamycin B, an antibiotic derived from Streptococcus mediterranei, with bacteriostatic and bactericidal actions. Inhibits DNA-dependent RNA polymerase activity in susceptible bacterial cells,
thereby suppressing RNA synthesis.
Active against Mycobacterium tuberculosis, M. leprae, Neisseria meningitidis, and a wide range of gram-negative and gram-positive organisms. It is used in conjunction with other antitubercular agents
to treat tuberculosis because resistant strains emerge rapidly when it is employed alone.
Primarily as adjuvant with other antituberculosis agents in initial treatment and retreatment of clinical tuberculosis; as
short-term therapy to eliminate meningococci from nasopharynx of asymptomatic carriers of N. meningitidis when risk of meningococcal meningitis is high.
Chemoprophylaxis in contacts of patients with Haemophilus influenzae type B infection; alone or in combination with dapsone and other antiinfectives in treatment of leprosy (especially dapsone-resistant
leprosy). Also infections caused by susceptible gram-negative and gram-positive bacteria that fail to respond to other antiinfectives;
in combination with erythromycin or tetracycline for treatment of Legionnaire's disease.
Hypersensitivity to rifampin; obstructive biliary disease; meningococcal disease; intermittent rifampin therapy; lactation.
Safe use during pregnancy (category C) or in children <5 y is not established.
Hepatic disease; history of alcoholism; concomitant use of other hepatotoxic agents.
Pulmonary Tuberculosis
Adult: PO/IV 600 mg once/d in conjunction with other antituberculosis agents
Child: PO 10–20 mg/kg/d (max: 600 mg/d)
Meningococcal Carriers
Adult: PO 600 mg b.i.d. for 2 consecutive d
Child: PO 10–20 mg/kg b.i.d. for 2 consecutive d (max: 600 mg/d)
Prophylaxis for H. influenzae Type B
Adult: PO 600 mg/d for 4 d
Child: PO 10–20 mg/kg/d for 4 d (max: 600 mg/d)
Dapsone-Sensitive Multibacillary Leprosy
Adult: PO 600 mg once/mo with clofazimine and dapsone for a minimum of 2 y
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Oral
- Give 1 h before or 2 h after a meal. Peak serum levels are delayed and may be slightly lower when given with food; capsule
contents may be emptied into fluid or mixed with food.
- Note: An oral suspension can be prepared from capsules for use with pediatric patients. Consult pharmacist for directions.
- Keep a desiccant in bottle containing capsules to prevent moisture causing instability.
| Intravenous PREPARE: IV Infusion: Dilute by adding 10 mL of sterile water for injection to each 600-mg vial to yield 60 mg/mL. Swirl to dissolve. Withdraw the
ordered dose and further dilute in 500 mL (preferred) of D5W. If necessary, 100 mL of D5W may be used.
ADMINISTER: IV Infusion: Infuse 500 mL solution over 3 h and 100 mL solution over 30 min. Note: A less concentrated solution infused over a longer
period is preferred.
INCOMPATIBILITIES Solution/additive: Minocycline. Y-site: Diltiazem.
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- Use diluted solution within 4 h of preparation.
CNS: Fatigue, drowsiness, headache, ataxia, confusion, dizziness, inability to concentrate, generalized numbness, pain in extremities,
muscular weakness. Special Senses: Visual disturbances, transient low-frequency hearing loss, conjunctivitis. GI: Heartburn, epigastric distress, nausea, vomiting, anorexia, flatulence, cramps, diarrhea, pseudomembranous colitis, transient elevations in liver function tests (bilirubin, BSP, alkaline phosphatase, ALT, AST), pancreatitis. Hematologic: Thrombocytopenia, transient leukopenia, anemia, including hemolytic anemia. Body as a Whole: Hypersensitivity (fever, pruritus, urticaria, skin eruptions, soreness of mouth and tongue, eosinophilia, hemolysis), flu-like
syndrome. Urogenital: Hemoglobinuria, hematuria, acute renal failure, light-chain proteinuria, menstrual disorders, hepatorenal syndrome, (with intermittent therapy). Respiratory: Hemoptysis. Other: Increasing lethargy, liver enlargement and tenderness, jaundice, brownish-red or orange discoloration of skin, sweat, saliva,
tears, and feces; unconsciousness.
Rifampin interferes with contrast media used for gallbladder study; therefore, test should precede daily dose of rifampin. May also cause retention of BSP. Inhibits standard assays for serum folate and vitamin B12.
Drug: Alcohol, isoniazid, pyrazinamide, ritonavir, saquinavir increase risk of drug-induced hepatotoxicity (including fatal hepatotoxicity when used for latent TB); p-aminosalicylic acid (PAS) decreases concentrations of rifampin; decreases concentrations of alfentanil, alosetron, alprazolam, amprenavir, barbiturates, benzodiazepines, carbamazepine, atovaquone, cevimeline, chloramphenicol, clofibrate, corticosteroids, cyclosporine, dapsone, delavirdine, diazepam, digoxin, diltiazem, disopyramide, estazolam, estramustine, fentanyl, fosphenytoin, fluconazole galantamine, indinavir, itraconazole, ketoconazole, lamotrigine, levobupivacaine, lopinavir, methadone, metoprolol, mexiletine, midazolam, nelfinavir, oral sulfonylureas, oral contraceptives, phenytoin, progestins, propafenone, propranolol, quinidine, quinine, ritonavir, sirolimus, theophylline, thyroid hormones, tocainide, tramadol, verapamil, warfarin, zaleplon, and zonisamide, leading to potential therapeutic failure.
Absorption: Readily absorbed from GI tract. Peak: 2–4 h. Distribution: Widely distributed, including CSF; crosses placenta; distributed into breast milk. Metabolism: Metabolized in liver to active and inactive metabolites; is enterohepatically cycled. Elimination: Up to 30% excreted in urine, 60–65% in feces. Half-Life: 3 h.
Assessment & Drug Effects
- Lab tests: Periodic liver function tests are advised. Closely monitor patients with hepatic disease.
- Check prothrombin time daily or as necessary to establish and maintain required anticoagulant activity when patient is also
receiving an anticoagulant.
Patient & Family Education
- Do not interrupt prescribed dosage regimen. Hepatorenal reaction with flu-like syndrome has occurred when therapy has been
resumed following interruption.
- Be aware that drug may impart a harmless red-orange color to urine, feces, sputum, sweat, and tears. Soft contact lenses may
be permanently stained.
- Report onset of jaundice, hypersensitivity reactions, and persistence of GI adverse effects to physician.
- Use or add barrier contraceptive if using hormonal contraception. Concomitant use of rifampin and oral contraceptives leads
to decreased effectiveness of the contraceptive and to menstrual disturbances (spotting, breakthrough bleeding).
- Keep drug out of reach of children.
- Do not breast feed while taking this drug.
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