[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)](https://durgical.com/en/pharmacology/classes/nucleoside-nucleotide-reverse-transcriptase-inhibitors/) › Lamivudine [Pharmacology](https://durgical.com/en/pharmacology/) · [Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)](https://durgical.com/en/pharmacology/classes/nucleoside-nucleotide-reverse-transcriptase-inhibitors/) # Lamivudine A very well tolerated NRTI found in almost every HIV regimen. It also suppresses hepatitis B virus. Updated 2026-11-01 - Class: [Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)](https://durgical.com/en/pharmacology/classes/nucleoside-nucleotide-reverse-transcriptase-inhibitors/) - Enzyme: HIV-1 reverse transcriptase - ATC code: J05AF05 - WHO Model List of Essential Medicines Also called: 3TC ✂**HIV-1 reverse transcriptase**Lamivudine ⓘ The figure shows lamivudine triphosphate, its active form, in the polymerase site of HIV-1 reverse transcriptase bound to DNA. **Target in 3D:** HIV-1 reverse transcriptase. PDB structure 6UJY (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/6UJY) · Drag to rotate · pinch to zoom ## Mechanism of action A cytidine analogue. Cellular kinases convert it to lamivudine triphosphate, which competes with dCTP; once incorporated into viral DNA it ends the chain. It acts the same way on the hepatitis B virus polymerase. The M184V mutation in reverse transcriptase removes its activity but makes the virus less fit to replicate. - It is phosphorylated to lamivudine triphosphate in the cell - It competes with dCTP at reverse transcriptase - It is built into viral DNA and ends the chain ## Pharmacokinetics **Absorption** Good oral absorption (bioavailability about 86% in adults) **Elimination** Mostly unchanged in urine, by active tubular secretion; it accumulates in kidney failure **Half-life** Plasma half-life about 5 to 7 hours ## Indications - HIV-1 infection, combined with other antiretrovirals [HIV infection and AIDS →](https://durgical.com/en/conditions/hiv-infection-and-aids/) - Chronic hepatitis B (with products made for that use) [Viral hepatitis →](https://durgical.com/en/conditions/viral-hepatitis/) ## Adverse effects ### Common - Headache - Nausea - Tiredness - Diarrhoea ### Serious (rare, important) - Severe hepatitis B flare after stopping it in co-infected people - Pancreatitis, mainly in children with risk factors - Lactic acidosis with hepatic steatosis (class effect) ## Contraindications - Previous hypersensitivity to lamivudine ## Key interactions **Emtricitabine** Both are cytidine analogues selecting the same resistance (M184V): they are not combined **Sorbitol (in syrups and solutions)** Can lower lamivudine concentrations; chronic co-use is avoided **Trimethoprim** Competes for tubular secretion and slightly raises lamivudine, without clinical importance ## What is monitored - Hepatitis B serology before starting - Liver tests for several months if stopped in hepatitis B co-infection - Kidney function - Viral load and CD4 ## Administration and safety - By mouth, as a tablet or solution - Hepatitis B products contain less drug: a person with HIV should only get HIV products, to avoid inducing resistance - Check fixed-dose combinations: many already contain lamivudine ## Nursing care - Check hepatitis B status before starting or stopping - Teach that it must not be stopped on one's own (risk of hepatitis B flare and resistance) - Watch for abdominal pain in children (pancreatitis) ## Pregnancy and breastfeeding Antiretroviral treatment in pregnancy protects the mother and lowers HIV transmission to the baby; the treating team chooses the regimen. ## Memory aid 'Lamivudine limps the virus': M184V beats it but leaves the virus less fit. ## Test yourself Think of the answer, then tap the question to see it. ## Besides HIV, which other virus does lamivudine suppress? Hepatitis B virus; that is why stopping it in a co-infected person can trigger a severe hepatitis flare. ## Why are lamivudine and emtricitabine not combined? They are near-identical cytidine analogues: they compete for the same pathway and select the same M184V mutation, with no added benefit. ## Why does lamivudine need adjustment in kidney failure? It is mostly removed unchanged in urine by tubular secretion, so it builds up when the kidney fails. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/lamivudine/) ## Related drugs - [Emtricitabine](https://durgical.com/en/pharmacology/emtricitabine/) - [Tenofovir disoproxil](https://durgical.com/en/pharmacology/tenofovir-disoproxil/) - [Dolutegravir + lamivudine + tenofovir disoproxil (TLD)](https://durgical.com/en/pharmacology/dolutegravir-lamivudine-tenofovir-disoproxil/) ## Related conditions - [HIV infection and AIDS](https://durgical.com/en/conditions/hiv-infection-and-aids/) - [Viral hepatitis](https://durgical.com/en/conditions/viral-hepatitis/) [← Back to the class: Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)](https://durgical.com/en/pharmacology/classes/nucleoside-nucleotide-reverse-transcriptase-inhibitors/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [DailyMed - LAMIVUDINE tablet, film coated](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=34c02bcc-d6ff-99d4-8e6a-4a91908adca8) (DailyMed (U.S. National Library of Medicine), 2026); [Lamivudine: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a696011.html) (MedlinePlus (U.S. National Library of Medicine), 2025); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=J05AF05) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/) (World Health Organization, 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/lamivudine/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/lamivudine/