Last Updated June 10, 2016
Nucleoside reverse transcriptase inhibitor antiretroviral
Indication: treatment of HIV infection in combination with other antiretrovirals; reduction of perinatal transmission of HIV, postexposure prophylaxis, in combination with other antiretrovirals. SA Formulary lists an unregistered use in HIV/hepatitis B coinfection.
Mechanism of action*: a cytosine analogue that is phosphorylated intracellularly to lamivudine 5’-triphosphate, which interferes with HIV viral RNA–dependent DNA polymerase inhibiting viral replication.
Pharmacokinetics*: renal excretion 70%. Half-life: serum = 2-4 hours; intracellular = 16-19 hours. Detectable levels found in cerebrospinal fluid after oral administration.
Adult Dose: 150 mg twice daily or 300 mg once daily.
Take without regard to meals.*
Use in Renal or Hepatic Insufficiency:
Dosage for patients with chronic kidney disease or end-stage renal disease†:
Zidovudine/lamivudine should be administered as separate component medications in patients with creatinine clearance < 50 mL/min.
Chronic hepatitis B infection: 100-150 mg daily.
Use in Pregnancy and Breastfeeding: Category C. Excreted in high concentrations in breast milk.
Use in Children:
Children with renal impairment:
Contraindicated in severe anaemia or neutropenia.
US Prescribing Information Boxed Warning*: hepatitis B virus testing should be done prior to initiation of lamivudine and caution used in coinfected patients.
Patients receiving lamivudine and other antiretroviral agents may continue to develop opportunistic infections and other complications of HIV infection. Patients should therefore remain under close supervision by medical practitioners experienced in the treatment of patients with HIV-associated diseases.*
Use with caution in patients with hepatitis B infection; rebound hepatitis may occur following therapy withdrawal.
Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues and other antiretrovirals.*
See above for pregnancy and lactation and paediatric dosing. Dosing adjustments in renal impairment and with hepatitis B monoinfection.
Minimal toxicity; adverse effects occur infrequently.
*Information from US prescribing information.
†Recommendation from South African Renal Society, 2008.