Used For:

• Treatment of HIV-1 infection in adults and adolescents (≥12 years) weighing ≥40 kgTypically part of combination antiretroviral therapy (ART), often with a third drug (e.g., dolutegravir or efavirenz)

Contraindications:

• Hypersensitivity to abacavir (potentially life-threatening; HLA-B*5701 testing recommended before starting therapy)Hypersensitivity to lamivudine or any component of the tabletSevere hepatic impairment (use with caution)

Side Effects:

• Common Side EffectsGastrointestinal: Nausea, vomiting, diarrhea, abdominal painCNS: Headache, fatigue, dizziness, insomniaMusculoskeletal: Myalgia, arthralgiaSkin: Rash (mild, maculopapular)Serious Side EffectsAbacavir hypersensitivity reaction (ABC-HSR):Occurs in ~5–8% of patientsSymptoms: fever, rash, nausea, vomiting, malaise, respiratory symptomsCan be fatal if therapy is continued; immediately discontinue if suspectedStrongly associated with HLA-B*5701 positive genotypeLactic acidosis / severe hepatomegaly with steatosis (rare but serious)Severe liver dysfunction (especially in patients with hepatitis B or C co-infection)

Precautions:

• HLA-B*5701 testing before starting abacavir; avoid in positive patientsUse caution in patients with renal impairment (lamivudine is renally excreted; dose adjustment may be needed)Monitor liver function tests in patients with hepatitis co-infectionAvoid abrupt discontinuation — may lead to viral reboundPregnancy: Generally safe, but must be supervised by an HIV specialistDrug interactions: Avoid co-administration with drugs that significantly alter abacavir or lamivudine metabolism (e.g., do not combine with stavudine or emtricitabine duplicatively)

Dietary Restrictions:

• Can be taken with or without foodMaintain balanced nutrition to support immune functionAvoid alcohol (risk of hepatotoxicity)Do not skip doses; maintain adherence to prevent resistanceAvoid herbal supplements without consulting the physician (may interact with ART drugs, e.g., St. John’s Wort)