LAMIVUDINE

(lam-i-vu'deen)

Epivir, Epivir-HBV, Heptovir

Classifications: antiretroviral agent; nucleoside reverse transcriptase inhibitor (nrti);
Therapeutic: antiretroviral; nrti
Pregnancy Category: C

Availability

100 mg, 150 tablets; 5 mg/mL, 10 mg/mL oral solution

Action

Lamivudine is a synthetic nucleoside analog reverse transcriptase inhibitor. It inhibits the transcription of the HIV viral RNA chain, as well as the hepatitis B viral RNA chain.

Therapeutic Effect

Antiviral action is effective against HIV viruses and hepatitis B (HBV) viral infections.

Uses

HIV infection in combination with zidovudine; treatment of chronic hepatitis B.

Contraindications

Hypersensitivity to lamivudine, pregnancy (category C), lactation.

Cautious Use

Renal impairment, renal failure; diabetes mellitus, diabetes mellitus; obesity; children.

Route & Dosage

HIV Infection
Adult: PO 150 mg b.i.d.
Child (3 mo–16 y): PO 4 mg/kg b.i.d. (max: of 150 mg b.i.d.)

Renal Impairment
Cl_cr 30–49 mL/min: 150 mg q.d.; 15–29 mL/min: 150 mg first dose, then 100 mg q.d.; 5–14 mL/min: 150 mg first dose, then 50 mg q.d.; <5 mL/min: 50 mg first dose, then 25 mg q.d.

Chronic Hepatitis B
Adult: PO 100 mg q.d.

Renal Impairment
Cl_cr 30–49 mL/min: 100 mg first dose, then 50 mg q.d.; 15–29 mL/min: 100 mg first dose, then 25 mg q.d.; 5–14 mL/min: 35 mg first dose, then 15 mg q.d.; <5 mL/min: 35 mg first dose, then 10 mg q.d.

Administration

Oral

Give Epivir b.i.d. in combination with AZT. The recommended dose for adults who weigh <50 kg (110 lb) is 2 mg/kg. Give Epivir-HBV qd; do NOT give in combination with AZT.
Store solution at 2°–25° C (36°–77° F) tightly closed.

Adverse Effects (≥1%)

CNS: Neuropathy, insomnia, sleep disorders, dizziness, depression, headache, fatigue, fever, chills. GI: Nausea, diarrhea, vomiting, anorexia, abdominal pain, cramps, dyspepsia, increased LFTs (ALT, amylase), hepatomegaly with steatosis. Hematologic: Neutropenia, anemia, thrombocytopenia. Musculoskeletal: Myalgia, arthralgia, malaise, pain. Skin: Rash. Respiratory: Nasal symptoms, cough. Metabolic: Lactic acidosis.

Interactions

Drug: Increases the C_max of zidovudine. Trimethoprim-sulfamethoxazole increases serum levels of lamivudine. Increased risk of lactic acidosis in combination with other reverse transcriptase inhibitors and antiretroviral agents.

Pharmacokinetics

Absorption: Rapidly absorbed from GI tract (86% reaches systemic circulation). Distribution: Low binding to plasma proteins. Metabolism: Minimal. Elimination: Excreted primarily unchanged in urine. Half-Life: 2–4 h.

Nursing Implications

Assessment & Drug Effects

Monitor children closely for S&S of pancreatitis; if they occur, immediately stop drug and notify physician.
Lab tests: Monitor CBC with differential, kidney & liver function, and serum amylase throughout therapy.
Monitor for and report all significant adverse reactions.

Patient & Family Education

Report any of the following immediately: nausea, vomiting, anorexia, abdominal pain, jaundice.
Note: The long-term effects of lamivudine are unknown.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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