Drug Class: Antiviral combinations
Usual Adult Dose for HIV Infection
1 tablet orally twice a day
Use: In combination with other antiretroviral agents or alone, for the treatment of HIV-1 infection
Usual Adult Dose for Nonoccupational Exposure
US CDC recommendations: 1 tablet orally twice a day
Duration of therapy: 28 days
Comments:
- Recommended as an alternative regimen for nonoccupational postexposure prophylaxis of HIV infection; this triple NRTI regimen is recommended only when a NNRTI-based or a protease inhibitor-based regimen cannot or should not be used.
- 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: 1 tablet orally twice a day
Duration of therapy: 28 days, if tolerated
Comments:
- Only with expert consultation, as 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
At least 40 kg: 1 tablet orally twice a day
Comments: Use of the individual components is recommended for patients less than 40 kg; the manufacturer product information for abacavir, lamivudine, and zidovudine should be consulted.
Use: In combination with other antiretroviral agents or alone, for the treatment of HIV-1 infection
Renal Dose Adjustments
CrCl less than 50 mL/min: Not recommended; individual components should be used.
Liver Dose Adjustments
Mild liver dysfunction (Child-Pugh A): Not recommended; individual components should be used.
Moderate or severe liver dysfunction (Child-Pugh B or C): Contraindicated
Precautions
US BOXED WARNINGS:
- HYPERSENSITIVITY REACTIONS: Serious and sometimes fatal hypersensitivity reactions (with multiple organ involvement) reported with abacavir. 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.
- HEMATOLOGIC TOXICITY: Zidovudine has been associated with hematologic toxicity (including neutropenia and severe anemia), especially in patients with advanced HIV-1 disease.
- MYOPATHY: Prolonged zidovudine use has been associated with symptomatic myopathy.
- 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.
- EXACERBATIONS OF HEPATITIS B: Severe acute exacerbations of hepatitis B reported in patients coinfected with HBV and HIV-1 after stopping lamivudine. Hepatic function of coinfected patients should be closely monitored with clinical and laboratory follow-up for at least several months after stopping this drug. If appropriate, initiation/resumption of antihepatitis B therapy may be necessary.
This drug is not recommended for use in pediatric patients weighing less than 40 kg.
Consult WARNINGS section for additional precautions.
Dialysis
Data not available
Other Comments
Administration advice:
- May administer without regard to food
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).
- Limited data available on the use of this drug alone in patients with higher baseline viral load (more than 100,000 copies/mL)
Monitoring:
- Hematologic: Blood counts (frequently in patients with advanced HIV-1 disease; periodically in other HIV-1-infected patients)
- Hepatic: Hepatic function of HIV-1/HBV-coinfected patients with clinical and laboratory follow-up (for at least several months after stopping therapy)
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.