Erlotinib

Products

Erlotinib is commercially available in the form of film-coated tablets (Tarceva). It has been approved in many countries since 2005. Generic versions were registered in 2018.

Structure and properties

Erlotinib (C22H23N3O4, Mr = 393.4 g/mol) is present in drugs as erlotinib hydrochloride, a white powder that is sparingly soluble in water. Solubility increases with decreasing pH. Erlotinib is an aniline-quinazoline derivative.

Effects

Erlotinib (ATC L01XE03) has cytostatic and cytotoxic properties. It is an inhibitor of the tyrosine kinase of EGFR (epidermal growth factor receptor). EGFR is proliferated on the surface of cancer cells. By inhibiting the tyrosine kinase, the cells are killed. Clinical trials have shown that the treatment prolongs survival.

Indications

For the treatment of patients with locally advanced or metastatic non-small cell lung cancer. Also used in some countries to treat metastatic pancreatic cancer in combination with gemcitabine.

Dosage

According to the SmPC. The drug is taken once daily at least one hour before or two hours after eating. Advisory:

  • Avoid strong sunlight (skin rashes may occur).
  • Quit smoking (reduces the effectiveness).
  • Consider drug interactions.
  • Take the drug on an empty stomach.

Contraindications

  • Hypersensitivity

For complete precautions, see the drug label.

Interactions

Erlotinib is metabolized primarily by CYP3A4 and to a lesser extent by CYP1A2 and CYP1A1. Corresponding drug-drug interactions are possible and relevant. The solubility of erlotinib is dependent on gastric pH. Antacids, proton pump inhibitors, and H2 antagonists may reduce bioavailability. Smoking also reduces bioavailability because it induces CYP1A1 and CYP1A2. Other interactions have been observed with anticoagulants and statins.

Adverse effects

The most common potential adverse effects include infectious disease, fatigue, poor appetite, conjunctivitis and other eye disorders, respiratory disorders, cough, indigestion, gastrointestinal bleeding, elevated liver enzymes, and rash. Rarely, severe side effects are possible, including fatal outcomes.