Lapatinib

Generic Details

Generic Name

Lapatinib

Other Names

  • Tykerb

Drug Class

  • Tyrosine Kinase Inhibitor

Chemical Formula

C29H26ClFN4O4S

Molecular Weight

581.06 g/mol

Mechanism of Action

  • Inhibits the tyrosine kinase activity of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2/neu)

Indications

  • Breast cancer (HER2-positive)

Common Dosage Forms

  • Tablet

Typical Dosage

  • 1250 mg orally once daily on days 1-21 of each 21-day cycle in combination with capecitabine

Pediatric Dosage

  • Safety and efficacy not established

Geriatric Dosage

  • Adjust dosage based on individual patient needs

Side Effects

  • Diarrhea
  • Rash
  • Nausea
  • Fatigue
  • Hepatotoxicity

Contraindications

  • Hypersensitivity to lapatinib or any component of the formulation

Pregnancy Category

  • Category D

Lactation Safety

  • Not recommended during breastfeeding

Drug Interactions

  • Strong CYP3A4 inhibitors
  • Strong CYP3A4 inducers

Overdose Symptoms

  • Severe diarrhea
  • Vomiting
  • Fatigue
  • Hepatotoxicity

Antidote for Overdose

  • No specific antidote, manage symptoms supportively

Storage Conditions

  • Store at room temperature (20-25°C)

Pharmacokinetics

  • Absorption: Rapidly absorbed after oral administration
  • Distribution: Extensively distributed in the body
  • Metabolism: Primarily hepatic through CYP3A4 and CYP3A5
  • Excretion: Mainly excreted in feces

Precautions

  • Monitor liver function tests regularly
  • Cardiotoxicity

Warnings

  • Severe hepatotoxicity
  • Interstitial lung disease

Others

  • Consider dose adjustments in hepatic impairment