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Nucleoside reverse transcriptase inhibitor

Lamivudine

Brand names: Epivir, Zeffix

Lamivudine is a nucleoside reverse transcriptase inhibitor used as part of combination antiretroviral therapy for HIV infection and for the treatment of chronic hepatitis B.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It is phosphorylated intracellularly to its active triphosphate, which inhibits viral reverse transcriptase and terminates the growing viral DNA chain.

Prescribing in practice

  • In patients co-infected with HIV and hepatitis B, stopping lamivudine can precipitate a severe hepatitis flare, so monitor closely after discontinuation.
  • Doses require adjustment in renal impairment as the drug is renally cleared.
  • Hepatitis B doses differ from HIV doses, and lamivudine must not be used as the only active antiretroviral for HIV to avoid resistance.

Monitoring

Monitor renal function and, in hepatitis B or co-infection, liver function and viral parameters, with vigilance for flares after stopping.

Counselling the patient

  • Take the medicine regularly to keep the virus suppressed and reduce resistance.
  • Do not stop treatment without specialist advice, as your liver infection can flare.
  • Report severe tiredness, muscle pain or breathlessness, which need medical review.

Evidence & guidelines

Lamivudine is an established component of recommended antiretroviral and chronic hepatitis B regimens; refer to BHIVA and NICE guidance.

Reference: BHIVA/EASL guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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