Abacavir Dosage & Rx Info | Uses, Side Effects

Abacavir Generic Name & Formulations

Legal Class

General Description

Abacavir (as sulfate) 300mg; scored tabs.

Pharmacological Class

Nucleoside analogue (reverse transcriptase inhibitor).

How Supplied

Tabs—Contact supplier; Soln—240mL

Manufacturer

Various generic manufacturers

Mechanism of Action

Abacavir is a carbocyclic synthetic nucleoside analogue. Abacavir is converted by cellular enzymes to the active metabolite, carbovir triphosphate (CBV-TP), an analogue of deoxyguanosine-5′-triphosphate (dGTP). CBV-TP inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate dGTP and by its incorporation into viral DNA.

Abacavir Indications

Indications

HIV-1 infection, in combination with other antiretroviral agents.

Abacavir Dosage and Administration

Adult

300mg twice daily or 600mg once daily. Mild hepatic impairment: 200mg twice daily (use oral soln for titration).

Children

<3mos: not established. ≥3mos (oral soln): 8mg/kg twice daily or 16mg/kg once daily; max 600mg daily. If able to swallow tabs: 14–<20kg: 300mg once daily or 150mg twice daily; ≥20–<25kg: 450mg once daily or 150mg in the AM and 300mg in the PM; ≥25kg: use Adult dose.

Abacavir Contraindications

Contraindications

Presence of HLA-B*5701 allele. Prior hypersensitivity reaction to abacavir (see full labeling). Moderate or severe hepatic impairment.

Abacavir Boxed Warnings

Boxed Warning

Hypersensitivity reactions.

Abacavir Warnings/Precautions

Warnings/Precautions

Screen for presence of HLA-B*5701 allele prior to starting therapy or reinitiation; if (+), abacavir is contraindicated. Discontinue immediately if hypersensitivity is suspected, regardless of HLA-B*5701 status and even when other diagnoses are possible. If hypersensitivity cannot be ruled out, do not restart. If stopped for reasons other than hypersensitivity, restart only if medical care can be readily accessed. Suspend if lactic acidosis or pronounced hepatotoxicity (eg, hepatomegaly, steatosis) occurs. Possible risk of MI; minimize risk factors for coronary heart disease (eg, hypertension, hyperlipidemia, diabetes, smoking). Women. Obesity. Elderly. Pregnancy. Nursing mothers: not recommended.

Abacavir Pharmacokinetics

Absorption

Absolute bioavailability: 83%.

Distribution

Volume of distribution: 0.86 ± 0.15 L/kg. Plasma protein bound: ~50%.

Metabolism

Hepatic.

Elimination

Renal, fecal. Half-life: 1.54 ± 0.63 hours.

Abacavir Interactions

Interactions

Potentiates riociguat. May be potentiated by ethanol. Antagonizes methadone.

Abacavir Adverse Reactions

Adverse Reactions

Nausea, vomiting, headache, malaise, fatigue, dreams/sleep disorders, diarrhea, fever, chills, rash (may be severe, eg, Stevens-Johnson), ear/nose/throat infections; hypersensitivity reactions (may be fatal), lactic acidosis, severe hepatomegaly with steatosis, immune reconstitution syndrome.

Abacavir

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