Adult: 150 mg bid or 300 mg once daily, in combination w/ other antiretrovirals. Child: As soln: >3 mth <14 kg: 4 mg/kg bid. As tab: 14-21 kg: 75 mg bid; 22-30 kg: 75 mg in the morning and 150 mg at night; >30 kg: 150 mg bid. Max: 300 mg daily. Doses are given in combination w/ other antiretrovirals.
Oral Chronic hepatitis B
Adult: 100 mg once daily. For patients w/ concomitant HIV infection: 150 mg bid or 300 mg once daily. Child: 2-17 yr 3 mg/kg once daily. Max: 100 mg daily.
Renal Impairment
Chronic hepatitis B:
CrCl (mL/min)
Dosage
<5
1st dose 35 mg, then 10 mg once daily.
5-14
1st dose 35 mg, then 15 mg once daily.
15-29
1st dose 100 mg, then 25 mg once daily.
30-49
1st dose 100 mg, then 50 mg once daily.
HIV infection:
CrCl (mL/min)
Dosage
<5
1st dose 50 mg, then 25 mg once daily.
5-14
1st dose 150 mg, then 50 mg once daily.
15-29
1st dose 150 mg, then 100 mg once daily.
30-49
1st dose 150 mg, then 150 mg once daily.
Administration
May be taken with or without food.
Contraindications
Hypersensitivity. Lactation.
Special Precautions
Patient w/ hepatomegaly, hepatitis or other risk factors for hepatic disease; childn w/ history or risk factors for pancreatitis. Pregnancy.
Monitor amylase, bilirubin, liver enzymes 3 mthly during therapy; haematologic parameters, HIV viral load, CD4 count; signs and symptoms of pancreatitis or hepatonecroinflammation; hepatitis B virus (HBV) DNA regularly during therapy. Monitor hepatic function for several mth following discontinuation of therapy. Perform HIV testing prior to and periodically during treatment.
Drug Interactions
Decreased renal excretion w/ high-dose trimethoprim. Severe anaemia may occur when used concomitantly w/ zidovudine. Treatment failure and emergence of resistance may result from once daily triple regimens of lamivudine and tenofovir w/ either abacavir or didanosine. May antagonise the antiviral action of zalcitabine. May enhance the adverse effect of emtricitabine.
Food Interaction
Food decreases rate of absorption.
Action
Description: Lamivudine, a synthetic nucleoside analogue, is phosphorylated into the body to the active 5'-triphosphate metabolite. It inhibits RNA- and DNA-dependent polymerase activities of reverse transcriptase via DNA chain termination. Pharmacokinetics: Absorption: Rapidly absorbed from the GI tract. Delayed absorption by ingestion w/ food. Bioavailability: 80-87%. Time to peak plasma concentration: Approx 1 hr. Distribution: Crosses the blood-brain barrier and placenta; enters breast milk. Volume of distribution: 1.3 L/kg. Plasma protein binding: Up to 36%. Metabolism: Metabolised intracellularly to the active metabolite lamivudine triphosphate via phosphorylation. Excretion: Via urine, mainly as unchanged drug. Elimination half-life: 5-7 hr.
J05AF05 - lamivudine ; Belongs to the class of nucleoside and nucleotide reverse transcriptase inhibitors. Used in the systemic treatment of viral infections.
References
Anon. Lamivudine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 15/09/2015.Buckingham R (ed). Lamivudine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 15/09/2015.Lamivudine Tablet, Film coated (Mylan Pharmaceuticals Inc). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 15/09/2015.