Lamivudine

Indications

Lamivudine is used for: HIV infection, Chronic hepatitis B

Adult Dose

Oral HIV infection Adult: 150 mg bid or 300 mg once daily, in combination with other antiretrovirals. Chronic hepatitis B Adult: 100 mg once daily. For patients with concomitant HIV infection: 300 mg once daily or in 2 divided doses.

Child Dose

Oral HIV infection Child: 3 mth-12 yr: 4 mg/kg bid. Max: 300 mg/day. Chronic hepatitis B Child: >2 yr: 3 mg/kg once daily. Max: 100 mg/day.

Renal Dose

Oral HIV infection Renal impairment: Dialysis patients: Not recommended. CrCl (ml/min) 30-49 1st dose 150 mg, then 150 mg once daily. 15-29 1st dose 150 mg, then 100 mg once daily. 5-14 1st dose 150 mg, then 50 mg once daily. <5 1st dose 50 mg, then 25 mg once daily. Chronic hepatitis B Renal impairment: Haemodialysis patients: Dose adjustment in accordance with CrCl. Peritoneal dialysis patients: Not recommended. CrCl (ml/min) 30-49 1st dose 100 mg, then 50 mg once daily. 15-29 1st dose 100 mg, then 25 mg once daily. 5-14 1st dose 35 mg, then 15 mg once daily. <5 1st dose 35 mg, then 10 mg once daily.

Administration

May be taken with or without food.

Contra Indications

Hypersensitivity. Lactation.

Precautions

Discontinue use if there is rapid increase in aminotransferase levels, progressive hepatomegaly, or metabolic or lactic acidosis of unknown origin. Discontinue use if clinical signs, symptoms or lab abnormalities suggestive of pancreatitis develop. Hepatomegaly or other risk factors for hepatic impairment. Monitor hepatic function in chronic hepatitis B patients. Exclude HIV infection prior to hepatitis B therapy. Renal impairment. Pregnancy.

Pregnancy-Lactation

Interactions

Renal excretion may be inhibited by high doses of trimethoprim (co-trimoxazole). May antagonise the antiviral action of zalcitabine.

Adverse Effects

Side effects of Lamivudine : >10% Cough,Diarrhea,Fatigue & malaise,Fever (peds),Headache,Musculoskeletal pain,Nausea,Nervous system neuropathy,Pancreatitis,Peripheral neuropathy,Nasal S/S,Vomiting 1-10% Abdominal cramps, abdominal pain,Anorexia &/or decr appetite,Arthralgia,Chills,Depression,Dizziness,Dyspepsia,Insomnia,Myalgia,Rash,Thrombocytopenia,Creatine phosphokinase increased Frequency Not Defined Body fat redistribution,Elevated amylase,Neutropenia,Hepatitis B exacerbation Potentially Fatal: Lactic acidosis associated with severe hepatomegaly and hepatic steatosis.

Mechanism of Action

Lamivudine, a nucleoside analogue, is phosphorylated in the body to the active triphosphate form. In the active form, it inhibits hepatitis B virus polymerase and HIV reverse transcriptase enzymes.