Lamivudine is an antiviral medicine used to treat chronic hepatitis B, in patients with active viral replication and liver inflammation. It reduces virus multiplication and helps control the disease. Because resistance can develop, treatment must be well planned and followed up by a doctor.
Also known as: Epivir, 3TC
Combining Lamivudine with Co-trimoxazole increases Lamivudine concentrations, with a risk of toxicity.
Lamivudine is predominantly eliminated by active renal secretion of organic cations, and trimethoprim (a co-trimoxazole component) inhibits those transporters (OCT), raising lamivudine plasma concentrations; the lamivudine label states this interaction is not considered clinically significant and that no lamivudine dose adjustment is needed. The co-trimoxazole label, however, recommends avoiding co-administration with OCT2 substrates whenever possible. In practice, the combination is common (HIV prophylaxis) and well tolerated; monitor for haematological or hepatic toxicity in susceptible patients.
Co-trimoxazole + lamivudine: trimethoprim inhibits OCT2 and raises lamivudine levels. No dose adjustment, but monitor for toxicity.
Trimethoprim reduces the renal tubular secretion of Lamivudine (via organic cation transport), increasing its exposure by about 40%.
Renal function and signs of Lamivudine toxicity (pancreatitis, anaemia, peripheral neuropathy).
Signs of Lamivudine toxicity (nausea, abdominal pain, anaemia, neuropathy) require reassessment.
Maintain surveillance; adjust the Lamivudine dose in renal impairment and watch for toxicity in prolonged therapy.
DailyMed/FDA (NIH/NLM) — approved Lamivudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6bd6b9da-df69-46db-813e-4e7f3bdecf95 ; approved Co-trimoxazole label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=08500fcb-dbec-4ac2-91c3-189d27907ec0 — with additional reference: Prontuário Terapêutico do INFARMED, INFARMED (11th ed., 2012)
Alcohol may worsen the underlying liver disease (especially in hepatitis B coinfection) during lamivudine treatment.
Limit or avoid alcohol intake during treatment.
DailyMed/FDA (NIH/NLM) — approved Lamivudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6bd6b9da-df69-46db-813e-4e7f3bdecf95
Lamivudine can be taken with or without food, with no relevant change in absorption.
May be taken with or without food, consistently.
DailyMed/FDA (NIH/NLM) — approved Lamivudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6bd6b9da-df69-46db-813e-4e7f3bdecf95
Nucleoside analogues, including lamivudine, can cause lactic acidosis and severe hepatic steatosis, sometimes fatal.
Stop with symptoms (nausea, abdominal pain, dyspnoea) or confirmed lactic acidosis.
DailyMed/FDA (NIH/NLM) — approved Lamivudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6bd6b9da-df69-46db-813e-4e7f3bdecf95
Lamivudine is predominantly renally excreted; in renal impairment the dose must be adjusted to avoid toxicity.
Adjust the dose to creatinine clearance.
DailyMed/FDA (NIH/NLM) — approved Lamivudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6bd6b9da-df69-46db-813e-4e7f3bdecf95
Lamivudine is used in pregnancy to prevent vertical transmission of HIV; it is not a known teratogen at therapeutic doses.
Use in pregnancy as part of the HIV antiretroviral regimen.
Excreted into breast milk; in HIV infection breastfeeding is not recommended regardless of treatment.
No specific additional contraception.
DailyMed/FDA (NIH/NLM) — approved Lamivudine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6bd6b9da-df69-46db-813e-4e7f3bdecf95
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Nucleoside analogue reverse transcriptase inhibitor (NRTI) active against HBV (and HIV); oral bioavailability ~86-87%; renal excretion — adjust in renal impairment. Limitation: resistance (YMDD mutation) with prolonged use.
Intracellularly phosphorylated to lamivudine-triphosphate, which inhibits viral reverse transcriptase by competing with deoxycytidine-triphosphate and chain termination of DNA — blocks HBV and HIV replication.
Well absorbed orally: absolute bioavailability 86±16% (150 mg tablet) and 87±13% (solution); serum peak 1.28±0.56 mcg/mL (HBV) 0.5-2 h after 100 mg; food does not alter absorption; volume of distribution 1.3±0.4 L/kg (extravascular distribution).
Intracellular metabolism (phosphorylation); predominantly renal excretion unchanged (glomerular filtration and active tubular secretion) — extend the dosing interval in renal impairment; minor hepatic oxidative metabolism.
Plasma half-life ~5-7 h; the intracellular half-life of lamivudine-triphosphate is 13-19 h (supports once-daily dosing in hepatitis B); no relevant accumulation with repeated dosing.
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
