rifabutin

rifabutin /rif·a·bu·tin/ (rif?ah-bu´tin) an antibacterial used for the prevention of disseminated complex (MAC) disease in patients with advanced HIV infection.

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rifabutin, (rif´būt´n),

n brand name: Mycobutin;
drug class: antimycobacterial agent;
action: inhibits deoxyribonucleic acid dependent ribonucleic acid (RNA) polymerase synthesis of bacterial RNA;
uses: prevention of disseminated
Mycobacterium avium complex (MAC) disease with advanced HIV infection.

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rifabutin

a rifamycin antibiotic with activity against mycobacteria.

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rifabutin

Mycobutin

Pharmacologic class: Rifamycin derivative

Therapeutic class: Antimycobacterial

Pregnancy risk category B

Action

Inhibits RNA synthesis by blocking RNA transcription in susceptible organisms (mycobacteria and some gram-positive and gram-negative bacteria)

Availability

Capsules: 150 mg

⊘Indications and dosages

➣ To prevent disseminated

Mycobacterium avium intracellulare complex in patients with advanced human immunodeficiency virus (HIV) infection

Adults: 300 mg P.O. daily as a single dose or in two divided doses

Off-label uses

• Tuberculosis
• Prophylaxis and treatment of M. avium intracellulare in children

Contraindications

• Hypersensitivity to drug
• Active tuberculosis

Precautions

Use cautiously in:
• severe hepatic disease
• pregnant or breastfeeding patients.

Administration

• Give in divided doses twice daily with food to reduce GI upset.

Route	Onset	Peak	Duration
P.O.	Unknown	2-3 hr	>24 hr

Adverse reactions

CNS: headache, asthenia, weakness

CV: pressure sensation in chest

EENT: uveitis; discolored tears, saliva, or sputum

GI: nausea, vomiting, diarrhea, dyspepsia, abdominal pain, eructation, flatulence, discolored feces, anorexia

GU: discolored urine

Hematologic: eosinophilia, neutropenia, leukopenia, thrombocytopenia

Musculoskeletal: joint pain, myalgia

Respiratory: dyspnea

Skin: rash, discolored skin or sweat

Other: abnormal taste, fever, flulike symptoms

Interactions

Drug-drug. Clarithromycin, itraconazole, saquinavir: reduced blood levels and efficacy of these drugs

Delavirdine: decreased delavirdine blood level, increased rifabutin blood level

Drugs metabolized by liver (such as zidovudine): altered blood levels of these drugs

Hormonal contraceptives: decreased contraceptive efficacy

Indinavir, nelfinavir, ritonavir: increased rifabutin blood level

Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase, eosinophils: increased levels

Neutrophils, platelets, white blood cells: decreased counts

Drug-food. High-fat foods: delayed drug absorption

Patient monitoring

• Monitor CBC with white cell differential. Watch for signs and symptoms of blood dyscrasias.
• Assess nutritional status.
• Closely monitor vital signs and temperature. Stay alert for dyspnea and flulike symptoms.

Patient teaching

• Advise patient to take twice daily with food (but not high-fat food) if GI upset occurs. To further minimize GI upset, teach him to eat small, frequent servings of healthy food and drink plenty of fluids.
• Instruct patient to take exactly as prescribed, even after symptoms subside.
☞ Tell patient to immediately report easy bruising or bleeding.
• Tell patient drug may turn tears, urine, and other body fluids reddish or brownish orange. Instruct him not to wear contact lenses during therapy because drug may stain them permanently.
• Inform patient that drug occasionally causes eye inflammation. Instruct him to report symptoms promptly.
• Caution patient to avoid driving and other hazardous activities until effects of drug are known.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.