Heptavir 150mg

Heptavir 150mg Tablet (Lamivudine 150mg)

Description

Heptavir 150mg contains Lamivudine, an antiretroviral medicine used to manage HIV-1 infection and chronic hepatitis B (HBV) infection. Lamivudine blocks the viral reverse transcriptase enzyme, preventing viral replication. It does not cure HIV or HBV but helps control infection and slows disease progression.

Medical Uses / Indications

• HIV-1 infection in adults and children, in combination with other antiretroviral medicines.

• Chronic hepatitis B infection in adults and pediatric patients.

Mechanism of Action

• Lamivudine is converted in the body to its active metabolite, lamivudine triphosphate (3TC-TP).

• 3TC-TP inhibits viral reverse transcriptase, blocking viral DNA synthesis and preventing replication.

Pharmacokinetics

Absorption: Well absorbed orally, bioavailability ~87%.
Distribution: Low plasma protein binding, volume of distribution ~1.3 L/kg.
Metabolism: Partially metabolized in the liver via the sulfoxide pathway.
Excretion: Mainly excreted unchanged by the kidneys; elimination half-life 5–7 hours.

Side Effects

Common:

• Headache, dizziness, insomnia, abnormal dreams

• Nausea, diarrhea, abdominal pain

• Fatigue, malaise, fever, rash

Laboratory Abnormalities:

• Anemia, neutropenia

• Elevated liver enzymes, increased amylase or lipase

Serious / Less Common:

• Pancreatitis

• Lactic acidosis with hepatic steatosis

• Severe skin reactions (Stevens–Johnson syndrome, toxic epidermal necrolysis)

• Myocardial infarction, seizures, rhabdomyolysis

Precautions

• HIV/HBV co-infection: Risk of hepatitis B flare after stopping therapy; monitor liver function.

• Renal impairment: Dose adjustment required; avoid if creatinine clearance <50 ml/min.

• Hepatic impairment: Use with caution in severe liver disease.

• Immune reconstitution syndrome may occur in HIV patients starting therapy.

• Pregnancy & Lactation: Category C; use only if benefits outweigh risks; avoid breastfeeding.

Drug Interactions

• Increased toxicity with ribavirin, ganciclovir, interferon alfa.

• Trimethoprim/Sulfamethoxazole may raise Lamivudine levels.

• Avoid drugs affecting kidney function to prevent elevated lamivudine exposure.

Contraindications

• Known hypersensitivity to Lamivudine or formulation excipients.

• Moderate to severe liver damage.

• HLA-B*5701 allele carriers (risk of hypersensitivity).

Overdose Management

• Managed supportively; hemodialysis can remove significant amounts due to low protein binding.

Dosage

For HIV-1 Infection (Adults):

• 150mg orally twice daily, or

• 300mg once daily (with other antiretroviral agents).

For Chronic Hepatitis B (Adults):

• 100mg orally once daily.

Pediatric Dosing:

• HIV-1: 3–10 mg/kg/day (max 300mg/day).

• HBV: 3 mg/kg/day (max 100mg/day).

Administration:

• Swallow tablets whole, with or without food.

Storage

• Store at 25°C (77°F).

• Protect from moisture, heat, and direct light.

Missed Dose

• Take missed dose as soon as possible.

• If close to the next scheduled dose, skip the missed one; do not double the dose.

• Always follow your doctor’s instructions.