Rifampin

A to Z Drug Facts

Rifampin

	Action
	Indications
	Contraindications
	Route/Dosage
	Interactions
	Lab Test Interferences
	Adverse Reactions
	Precautions
Patient Care Considerations
	Administration/Storage
	Assessment/Interventions
	Patient/Family Education

(RIFF-am-pin)

Rifadin, Rimactane, Rofact

Class: Anti-infective/Antitubercular

Action Inhibits DNA-dependent RNA polymerase in susceptible strains of bacteria.

Indications Adjunctive treatment of tuberculosis; short-term management to eliminate meningococci from nasopharynx in Neisseria meningitidis carriers. Unlabeled use(s): 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.

Contraindications Hypersensitivity to any rifamycin.

Route/Dosage

Tuberculosis

ADULTS: PO/IV 600 mg once daily. CHILDREN: PO/IV 10 to 20 mg/kg/day (max 600 mg/day).

Meningococcal Carriers

ADULTS: PO/IV 600 mg once daily for 4 consecutive days. CHILDREN ³ 1 Mo: PO/IV 10 mg/kg q 12 hr for 2 consecutive days. CHILDREN < 1 MO: 5 mg/kg q 12 hr for 2 consecutive days.

Interactions

Oral anticoagulants, 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, quinidine, quinine, ritonavir, sulfonylureas, tacrolimus, tamoxifen, theophyllines, tocainide, toremifene, tricyclic antidepressants, troleandomycin, verapamil, zolpidem: Therapeutic efficacy may be decreased due to 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 concomitant administration. Isoniazid: May result in higher rate of hepatotoxicity. Ketoconazole: May cause treatment failure of either ketoconazole or rifampin. Probenecid: Elevates rifampin levels.

Lab Test Interferences May inhibit standard microbiological assays for serum folate and vitamin B₁₂. Thus, use alternate assay methods. Transient abnormalities in liver function tests (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

CV: Hypotension; shock. CNS: Headache; drowsiness; fatigue; dizziness; inability to concentrate; mental confusion; generalized numbness; behavioral changes; myopathy. DERM: Rash; pruritus; urticaria; pemphigoid reaction; flushing. EENT: Visual disturbances; exudative conjunctivitis. GI: Heartburn; epigastric distress; anorexia; nausea; vomiting; gas; cramps; diarrhea; sore mouth and tongue; pseudomembranous colitis; pancreatitis. GU: Hemoglobinuria; hematuria; renal insufficiency; acute renal failure. HEMA: Eosinophilia; transient leukopenia; hemolytic anemia; decreased hemoglobin; hemolysis; thrombocytopenia. HEPA: Asymptomatic elevations of liver enzymes and hepatitis. RESP: Shortness of breath; wheezing. OTHER: 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.

Precautions

Pregnancy: Category C. Lactation: Excreted in breast milk. Discontinue nursing or drug. Body fluids: Medication may cause harmless red-orange discoloration of urine, feces, saliva, sputum, sweat, and tears. Soft contact lenses may be permanently stained. Hepatic impairment: Dosage adjustment is necessary.

PATIENT CARE CONSIDERATIONS

Administration/Storage

Administer oral form 1 hr before or 2 hr after meals.
Observe IV site closely for extravasation.
For IV infusion, reconstitute powder in 10 mL of Sterile Water for Injection and swirl gently. Reconstituted solution is stable at room temperature for 24 hr. Withdraw appropriate dose of drug, mix with 500 mL of D5W, and infuse over 3 hr. If ordered, drug may be added to 100 mL and infused over 30 min. A less concentrated solution infused over a longer period is preferred.
If D5W is contraindicated, use sterile saline. Do not mix with other solutions.
Initial dilutions of drug in vial are stable for 24 hr at room temperature.
Use final dilution (500 or 100 mL volumes) within 24 hr because precipitation may occur after this time period.
Administer solution for injection by IV route only. Do not administer IM or SC.

Assessment/Interventions

Obtain patient history, including drug history, history of medication noncompliance, and any known allergies.
Obtain baseline CBC and liver and renal function test results, and monitor at regular intervals.
Assess skin prior to starting drug and during treatment for rash, pruritus, flushing, urticaria, and jaundice.
Assess baseline neurologic status and observe for changes.
Monitor I&O and assess for development of edema.

OVERDOSAGE: SIGNS & SYMPTOMS
	Nausea, vomiting, increasing lethargy, unconsciousness, liver enlargement, jaundice, increased direct and total bilirubin levels, altered hepatic enzyme levels

Patient/Family Education

Instruct patient to take drug on empty stomach, 1 hr before or 2 hr 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 physician 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 physician 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 TB. Medication noncompliance reduces efficacy and promotes resistance.
Caution patient to avoid alcohol.