Abacavir Dolutegravir And Lamivudine 600/50/300 Tablets

Q1: What is INBEC (Abacavir/Dolutegravir/Lamivudine) used for?

INBEC is a single-tablet regimen (STR) combining Abacavir 600mg + Dolutegravir 50mg + Lamivudine 300mg for once-daily complete HIV-1 treatment. It is equivalent to the branded Triumeq and is a WHO-recommended first-line regimen.

Q2: How do all three components work together?

Abacavir and Lamivudine (two NRTIs) block HIV reverse transcriptase from copying viral RNA into DNA. Dolutegravir (INSTI) blocks integrase from inserting the viral DNA into the host chromosome. Together they target two critical HIV replication steps with triple-class synergy.

Q3: What HLA testing is required before starting INBEC?

HLA-B*5701 testing is mandatory before prescribing this regimen due to the Abacavir component. Patients who test positive for HLA-B*5701 must not receive Abacavir — an alternative NRTI backbone (TDF/FTC or TAF/FTC) should be used instead.

Q4: How should INBEC be taken?

Take one tablet once daily at a consistent time. Ideally on an empty stomach or with a light meal — Dolutegravir absorption is reduced by calcium-rich foods and antacids, which should be taken at least 2 hours before or 6 hours after the tablet.

Q5: What makes this regimen highly durable against resistance?

Dolutegravir has the highest genetic barrier to resistance among all INSTIs, requiring multiple rare mutations to develop resistance. Combined with the dual NRTI backbone, this regimen rarely fails virologically in adherent patients.

Q6: What are the most common side effects?

Insomnia and headache are the most frequently reported side effects (from Dolutegravir). Nausea, diarrhea, and fatigue can occur early in treatment but usually improve. Neuropsychiatric symptoms (anxiety, depression) affect some patients.

Q7: What is the Abacavir hypersensitivity warning for INBEC?

Any patient on INBEC who develops fever, skin rash, nausea, vomiting, malaise, or respiratory symptoms (especially in the first 6 weeks) must stop the regimen IMMEDIATELY and seek medical care. Rechallenge with Abacavir can cause fatal hypotension.

Q8: Is INBEC safe during pregnancy?

Dolutegravir-based regimens are now recommended in pregnancy by many guidelines. However, HLA-B*5701 testing is still required, and the full regimen must be discussed with your HIV specialist and obstetric team.

Q9: What drug interactions affect INBEC?

Rifampicin and rifabutin reduce Dolutegravir levels — dose adjustment needed. Antacids, iron, and calcium reduce Dolutegravir absorption. Metformin levels are increased by Dolutegravir — monitor and adjust. Always disclose all medications to your HIV specialist.

Q10: What monitoring is required on INBEC?

CD4 count and viral load at baseline, then at 4–8 weeks, then every 3–6 months. Liver function tests at baseline and periodically. Serum creatinine may rise slightly with Dolutegravir (not a true kidney effect — inhibits tubular creatinine secretion).

Q11: How should INBEC tablets be stored?

Store at room temperature (below 30°C), away from moisture and light. Keep in original packaging out of reach of children.

Q12: Do I need a prescription for INBEC?

Yes. INBEC requires specialist HIV prescribing, HLA-B*5701 pre-screening, and regular viral load monitoring to ensure ongoing suppression.