Classifications: antiviral agent; antiretroviral agent; nucleoside reverse transcriptase inhibitor (nrti); Therapeutic: antiviral; antiretroviral (nrti)
Pregnancy Category: C
300 mg tablets; 20 mg/mL oral solution
Abacavir is a synthetic nucleoside analogue with inhibitory activity against HIV. It inhibits the activity of HIV-1 reverse
transcriptase (RT) both by competing with the natural DNA nucleoside and by incorporation into viral DNA.
Abacavir prevents the formation of viral DNA replication. Therefore the viral load decreases as measured by an increased
CD4 lymphocyte cell count and suppression of HIV RNA, indicated by decreased HIV RNA copies, in HIV-positive individuals with
little or no exposure to zidovudine (AZT).
Treatment of HIV infection in combination with other antiretroviral agents.
Hypersensitivity to abacavir (fatal rechallenge reactions reported); lactic acidosis; creatinine clearance of <50 mL/min;
severe hepatomegaly; pregnancy (category C); lactation.
Prior resistance to another nucleoside reverse transcriptase inhibitor (NRTI); hepatic dysfunction; older adults.
Route & Dosage
Adult: PO 300 mg b.i.d.
Child (3 mo16 y): PO 8 mg/kg b.i.d. (max: 300 mg b.i.d.)
Mild (Child-Pugh score 56): 200 mg b.i.d.
- Tablets & oral solution are interchangeable on a mg-for-mg basis.
- Store tablets and liquid at 20°25° C (68°77° F). Liquid may be refrigerated.
Adverse Effects (≥1%)Body as a Whole:
Hypersensitivity reactions (including fever, skin rash, fatigue
, nausea, vomiting, diarrhea, abdominal pain); malaise; lethargy;
myalgia; arthralgia; paresthesia; edema; shortness of breath. CNS: Insomnia
, headache, fever. CV:
Hypotension (associated with hypersensitivity reaction). GI: Hepatomegaly
with steatosis, nausea, vomiting, diarrhea, anorexia,
pancreatitis, increased GGT, increased liver function tests. Skin: Rash. Other:
Lactic acidosis, renal insufficiency.
may increase abacavir blood levels.
Rapidly absorbed, 83% bioavailable. Distribution:
Distributes into extravascular space and erythrocytes; 50% protein bound. Metabolism:
Metabolized by alcohol
dehydrogenase and glucuronyl transferase to inactive metabolites. Elimination:
84% in urine, primarily as inactive metabolites; 16% excreted in feces. Half-Life:
Assessment & Drug Effects
- Monitor for S&S of hypersensitivity: fever, skin rash, fatigue, GI distress (nausea, vomiting, diarrhea, abdominal pain).
Withhold drug immediately & notify physician if hypersensitivity develops.
- Lab tests: Periodically monitor liver function, BUN and creatinine, CBC with differential, triglyceride levels, and blood
glucose, especially in diabetics.
- Withhold drug & notify physician for S&S of acidosis, hepatotoxicity, or renal insufficiency.
Patient & Family Education
- Take drug exactly as prescribed at indicated times. Missed dose: Take immediately, then resume dosing schedule. Do not double
- Withhold drug immediately & notify physician at first sign of hypersensitivity reaction (see Assessment & Drug Effects).
- Carry Warning Card provided with drug at all times.