Drug Detail:Abacavir (Abacavir [ a-bak-a-veer ])
Drug Class: Nucleoside reverse transcriptase inhibitors (NRTIs)
Usual Adult Dose for HIV Infection
300 mg orally twice a day or 600 mg orally once a day
Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection
Usual Adult Dose for Nonoccupational Exposure
US CDC recommendations: 300 mg orally twice a day or 600 mg orally once a day
Duration of therapy: 28 days
Comments:
- Recommended as part of alternative regimens (NNRTI-based, protease inhibitor-based, or triple NRTI) for nonoccupational postexposure prophylaxis of HIV infection
- Prophylaxis should be started as soon as possible, within 72 hours of exposure.
- Current guidelines should be consulted for additional information.
Usual Adult Dose for Occupational Exposure
US Public Health Service working group recommendations: 300 mg orally twice a day or 600 mg orally once a day
Duration of therapy: 28 days, if tolerated
Comments:
- Only with expert consultation, as part of an alternative regimen for use as HIV postexposure prophylaxis
- Prophylaxis should be started as soon as possible, preferably within hours after exposure.
- The optimal duration of prophylaxis is unknown and may differ based on institution protocol.
- Current guidelines should be consulted for additional information.
Usual Pediatric Dose for HIV Infection
3 months or older:
Oral solution: 8 mg/kg orally twice a day or 16 mg/kg orally once a day
Maximum dose: 600 mg/day
Tablets:
14 to less than 20 kg: 150 mg orally twice a day or 300 mg orally once a day
20 to less than 25 kg: 150 mg orally in the morning and 300 mg in the evening, or 450 mg orally once a day
25 kg or more: 300 mg orally twice a day or 600 mg orally once a day
Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection
Renal Dose Adjustments
Data not available
Liver Dose Adjustments
Mild liver dysfunction (Child-Pugh A): 200 mg orally twice a day
Moderate or severe liver dysfunction: Contraindicated
Precautions
US BOXED WARNINGS:
- HYPERSENSITIVITY REACTIONS: Serious and sometimes fatal hypersensitivity reactions (with multiple organ involvement) reported with this drug. Patients with the human leukocyte antigen subtype B*5701 (HLA-B*5701) allele are at higher risk of abacavir hypersensitivity reactions; however, such reactions have occurred in patients without the HLA-B*5701 allele. This drug is contraindicated in patients with prior hypersensitivity reaction to abacavir and in HLA-B*5701-positive patients. All patients should be screened for the HLA-B*5701 allele before starting or restarting treatment with this drug (unless HLA-B*5701 allele assessment previously documented). Regardless of HLA-B*5701 status, this drug should be discontinued without delay if hypersensitivity reaction is suspected, even if other diagnoses are possible. After hypersensitivity reaction to this drug, NEVER restart this or any other abacavir-containing product as more severe symptoms (including death) can occur within hours. Similar severe reactions also reported after restarting abacavir-containing products in patients with no history of abacavir hypersensitivity.
- LACTIC ACIDOSIS AND SEVERE HEPATOMEGALY WITH STEATOSIS: Lactic acidosis and severe hepatomegaly with steatosis (including fatalities) reported with use of nucleoside analogs and other antiretrovirals. This drug should be discontinued if clinical or laboratory findings suggest lactic acidosis or pronounced hepatotoxicity.
Safety and efficacy have not been established in patients younger than 3 months.
Consult WARNINGS section for additional precautions.
Dialysis
Data not available
Other Comments
Administration advice:
- Use in combination with other antiretroviral agents.
- May administer without regard to food
- If patient is unable to reliably swallow a tablet, use the oral solution.
- Consult the manufacturer product information regarding missed doses.
Storage requirements:
- Oral solution: Store at 20C to 25C (68F to 77F); may refrigerate; do not freeze.
- Tablets: Store at 20C to 25C (68F to 77F).
General:
- Screening for HLA-B*5701 allele recommended before starting this drug.
- Before starting this drug, medical history should be reviewed for prior exposure to any abacavir-containing product (to prevent reintroduction in patient with history of abacavir hypersensitivity).
Patient advice:
- Always read the Medication Guide and Warning Card (with information about abacavir hypersensitivity reaction) dispensed with each new and refill prescription; carry the Warning Card.
- Contact physician immediately if signs/symptoms of hypersensitivity develop; do not restart this or any other abacavir-containing product after a hypersensitivity reaction.
- If this drug is stopped for any reason besides hypersensitivity, do not restart it (or any other abacavir-containing product) without consulting physician; medical care must be readily accessible.