Abacavir sulfate
Abacavir sulfate (Ziagen)
Abacavir sulfate
(uh- BACK-ah-veer)
Pregnancy Category: C Ziagen (Rx)

Classification: Antiviral, antiretroviral drug

See Also: See also Antiviral Drugs.

Action/Kinetics: Synthetic nucleoside analog. Converted intracellularly to the active carbovir triphosphate. Carbovir triphosphate inhibits the activity of HIV-1 reverse transcriptase by competing with the natural substrate deoxyguanosine-5'-triphosphate and by incorporation into viral DNA. The lack of a 3'-OH group in the incorporated nucleoside analog prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation. Thus, viral DNA growth is terminated. Cross resistance in vitro has been seen to lamivudine, didanosine, and zalcitabine. Rapidly absorbed after PO use. Metabolized in the liver and excreted in both the urine and feces.

Uses: In combination with other antiretroviral drugs (e.g., lamivudine and zidovudine) to treat HIV-1 infection. Do not add as a single agent when antiretroviral regimens are changed due to loss of virologic response.

Special Concerns: Fatal hypersensitivity reactions are possible (See Side Effects). Efficacy for long-term suppression of HIV RNA or disease progression have not been determined. Abacavir is not a cure for HIV infection; clients may continue to show illnesses associated with HIV infection, including opportunistic infections. The drug has not been shown to reduce the risk of transmission of HIV to others through sexual contact or blood. Use with caution with liver disease.

Side Effects: Hypersensitivity: Fever, skin rash, fatigue, N&V;, diarrhea, abdominal pain, malaise, lethargy, myalgia, arthralgia, edema, SOB, paresthesia, lymphadenopathy, conjunctivitis, mouth ulcerations, maculopapular or urticarial rash life-threatening hypotension, liver failure, renal failure, death. GI: N&V;, diarrhea, loss of appetite, pancreatitis. Miscellaneous: Severe hepatomegaly with steatosis (may be fatal), lactic acidosis, pancreatitis, insomnia, other sleep disorders, headache, fever, skin rashes.

Laboratory Test Alterations: LFTs, CPK, GGT, creatinine, glucose, triglycerides. Lymphopenia, anemia, neutropenia.

Drug Interactions: Ethanol excretion of abacavir exposure.

How Supplied: Oral Solution: 20 mg/mL; Tablets: 300 mg

Dosage
?Oral Solution, Tablets Treat HIV-1 infection.
Adults: 300 mg b.i.d. with other antiretroviral drugs. Pediatric, 3 months to 16 years: 8 mg/kg b.i.d., not to exceed 300 mg b.i.d., in combination with other antiretroviral drugs.