Viramune

Action

Inhibits human immunodeficiency virus (HIV) nonnucleoside reverse transcriptase by binding directly to reverse transcriptase and blocking RNA-dependent and DNA-dependent polymerase activity

Availability

Oral suspension: 50 mg/5 ml

Tablets: 200 mg

Tablets (extended-release): 400 mg

Indications and dosages

➣ Treatment of HIV-1 infection

Adults: 200 mg P.O. daily for 14 days, then 200 mg (immediate-release) P.O. b.i.d., given in combination with other antiretrovirals; 400 mg (extended-release) P.O. daily after either a 14-day 200-mg lead-in regimen or after switching from a 200-mg b.i.d. regimen.

Children ages 15 days and older: 150 mg/m² (immediate-release tablet or oral suspension) P.O. once daily for 14 days, followed by 150 mg/m² b.i.d. thereafter. Total daily dosage shouldn't exceed 400 mg for any patient.

Dosage adjustment

• Chronic hemodialysis

Off-label uses

• Prophylaxis of maternal-fetal HIV transmission

Contraindications

• Hypersensitivity to drug or its components

• Moderate or severe hepatic impairment (Child-Pugh Class B or C, respectively)

• Use as part of occupational and nonoccupational postexposure prophylaxis regimens

Precautions

Use cautiously in:

• impaired renal or hepatic function

• pregnant or breastfeeding patients

• children.

Administration

• Be aware that drug should be given alone for first 14 days to reduce incidence of rash.

• If patient experiences rash during 14-day lead-in period with immediate-release form, don't initiate extended-release form until rash has resolved.

• Don't continue immediate-release lead-in dosing regimen beyond

28 days. If immediate-release dosing is interrupted for more than 7 days, restart recommended dosing, including 14-day lead-in dosing.

• For patients who interrupt extended-release dosing for more than 7 days, restart recommended lead-in dosing with immediate-release form using one 200-mg tablet daily for first 14 days.

• Be aware that drug shouldn't be started in adult females with CD4+ cell counts greater than 250/mm³ or in adult males with CD4+ cell counts greater than 400/mm³ because of serious and life-threatening hepatotoxicity, unless benefit outweighs risk.

• Give with or without food.

Adverse reactions

CNS: paresthesia, headache, malaise, fatigue

GI: nausea, diarrhea, abdominal pain

Hematologic: agranulocytosis

Hepatic: hepatitis, hepatotoxicity, hepatic failure

Musculoskeletal: myalgia, pain

Skin: rash, blistering, toxic epidermal necrolysis, Stevens-Johnson syndrome

Other: fever

Interactions

Drug-drug. Antiarrhythmics, antifungals, calcium channel blockers, cancer chemotherapy, ergot alkaloids, immunosuppressants, motility agents, opiate agonists: possible decreased plasma concentrations of these drugs

Anticoagulants: possible increased or decreased anticoagulant plasma concentrations

Clarithromycin, efavirenz, indinavir, ketoconazole, methadone: decreased activity of these drugs

Ethinyl estradiol, norethindrone: decreased contraceptive plasma levels Fluconazole: increased nevirapine level Lopinavir/ritonavir: decreased lopinavir activity

Nelfinavir: decreased nelfinavir active metabolite, minimum nelfinavir concentration

Rifabutin: increased rifabutin level

Drug-diagnostic tests. Alanine amino-transferase, aspartate aminotransferase, bilirubin, gamma-glutamyltransferase: increased levels

Hemoglobin, neutrophils: decreased levels

Drug-herbs. St. John's wort: decreased nevirapine blood level

Patient monitoring

Check closely for rash (which may be first sign of Stevens-Johnson syndrome), especially during first 6 months of therapy.

• Monitor patient's weight, temperature, and chest X-ray periodically.

• Assess patient's appetite and energy and physical activity levels.

• Monitor liver function tests and CBC with white cell differential.

Patient teaching

• Tell patient he may take with or without food.

• Tell patient or caregiver to shake suspension gently before use and that it's important to take the entire measured dose of suspension by using an oral dosing syringe or dosing cup.

• Tell patient or caregiver that the extended-release tablet must be swallowed whole and must not be chewed, crushed, or divided.

• Instruct patient to take missed dose as soon as he remembers. But if it's almost time for next dose, tell him to skip missed dose. Caution him not to double the dose.

• Inform female patient that hormonal contraceptives, implants, or shots may be ineffective during nevirapine therapy. Urge her to use alternative birth-control method.

Teach patient to recognize and immediately report rash, easy bruising or bleeding, and signs and symptoms of hepatotoxicity.

• Inform patient that nevirapine won't cure HIV or prevent its transmission.

• Caution female not to breastfeed, because breast milk may transfer HIV to infant.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and herbs mentioned above.