What is Erlotinib?

Erlotinib is an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) used primarily in the treatment of non‑small cell lung cancer (NSCLC) and pancreatic cancer. By inhibiting EGFR signaling, erlotinib slows tumor growth and helps improve patient outcomes in cancers that express EGFR mutations.

Reference: U.S. FDA Tarceva Prescribing Information; ClinicalTrials.gov (e.g., NCT00322452)

What are the other popular names for Erlotinib?

Erlotinib is most widely marketed under the brand name Tarceva®. In clinical literature, it is also referred to by its generic name, erlotinib.

Reference: MedlinePlus; U.S. FDA

What is the drug classification of Erlotinib?

Erlotinib is classified as an EGFR tyrosine kinase inhibitor (TKI). It belongs to the class of targeted anticancer agents used primarily in oncology for the treatment of EGFR‑mutated cancers.

Reference: World Health Organization (WHO) Oncology Guidelines; U.S. FDA

What is the mode of action of Erlotinib?

Erlotinib functions by competitively binding to the ATP-binding site of the intracellular domain of the EGFR. This binding inhibits receptor autophosphorylation and downstream signaling pathways (such as the MAPK and PI3K/AKT pathways), which are critical for tumor cell proliferation, survival, and metastasis. This inhibition leads to reduced tumor growth and increased apoptosis in EGFR‑driven cancers.

Reference: PubMed (Lynch et al., 2004, N Engl J Med); U.S. FDA

What are the primary uses of Erlotinib?

Erlotinib is primarily indicated for:

• Non‑Small Cell Lung Cancer (NSCLC): Particularly in patients with advanced or metastatic NSCLC harboring EGFR-sensitizing mutations.
• Pancreatic Cancer: In combination with gemcitabine for locally advanced, unresectable, or metastatic pancreatic cancer.

Reference: U.S. FDA Tarceva Prescribing Information; ClinicalTrials.gov

What is the recommended dosage and administration for Erlotinib?

• Dosage for NSCLC: The standard oral dosage is 150 mg once daily.
• Dosage for Pancreatic Cancer: Often used at the same dosage (150 mg once daily) in combination with gemcitabine.
• Administration:
  • Erlotinib should be taken on an empty stomach (1 hour before or 2 hours after a meal) to maximize absorption.
  • Consistent daily dosing at the same time is recommended.

Reference: U.S. FDA Tarceva Prescribing Information; ClinicalTrials.gov (e.g., NCT00322452)

What prescribing information is important for Erlotinib?

• Indications:
  • Approved for advanced NSCLC with EGFR mutations and for use in combination with gemcitabine in pancreatic cancer.
• Contraindications:
  • Contraindicated in patients with a known hypersensitivity to erlotinib or any of its components.
• Monitoring:
  • Regular monitoring of liver function, complete blood counts, and dermatologic assessments are necessary.
• Special Considerations:
  • EGFR mutation testing is recommended prior to treatment in NSCLC to identify patients likely to benefit.
  • Dose adjustments may be required in patients with hepatic impairment.

Reference: U.S. FDA Tarceva Prescribing Information; NCCN Guidelines

What safety information, side effects, warnings, and cautions are associated with Erlotinib?

• Common Side Effects:
  • Skin rash (often acneiform), diarrhea, nausea, vomiting, loss of appetite, and fatigue.
• Serious Side Effects:
  • Interstitial lung disease (ILD)/pneumonitis, which can be life‑threatening; severe skin reactions (e.g., Stevens-Johnson syndrome) and liver toxicity.
• Warnings & Cautions:
  • Pulmonary Toxicity: Monitor for new or worsening respiratory symptoms; discontinue therapy if ILD is suspected.
  • Dermatologic Reactions: Severe skin rash may require dose reduction or discontinuation.
  • Hepatotoxicity: Regular liver function tests are essential; significant abnormalities warrant intervention.
  • Diarrhea: Can lead to dehydration; advise patients to maintain hydration and seek medical advice if severe.
  • Drug Interactions: Concomitant use with CYP3A4 inhibitors or inducers may alter erlotinib levels.
• Pregnancy:
  • Erlotinib is contraindicated in pregnancy due to potential teratogenic effects; women of childbearing potential must use effective contraception.

Reference: U.S. FDA Tarceva Prescribing Information; NEJM; PubMed

What drug interactions should be considered with Erlotinib?

• CYP3A4 Inhibitors:
  • Strong inhibitors (e.g., ketoconazole, clarithromycin) can increase erlotinib plasma levels, enhancing the risk of toxicity.
• CYP3A4 Inducers:
  • Inducers (e.g., rifampin, carbamazepine) may lower erlotinib levels, reducing its efficacy.
• Other Medications:
  • Caution with drugs that may compound gastrointestinal toxicity or hepatotoxicity.

Reference: U.S. FDA; Clinical Pharmacology Reviews on PubMed

Frequently Asked Questions (FAQs)

Q: How soon will I see results with Erlotinib?
A: Improvement in symptoms may occur within a few weeks, though maximum benefit in tumor response might take several months of continuous treatment.

Q: Can Erlotinib be taken with food?
A: For optimal absorption, it is recommended that erlotinib be taken on an empty stomach—either 1 hour before or 2 hours after a meal.

Q: What should I do if I develop a severe skin rash?
A: Contact your healthcare provider immediately. Severe rash may indicate a need for dose adjustment or discontinuation due to risk of serious adverse reactions.

Q: Is EGFR mutation testing necessary before starting Erlotinib?
A: Yes, EGFR mutation testing is essential to ensure that the patient is likely to benefit from erlotinib therapy.

Q: What precautions should I take regarding liver health while on Erlotinib?
A: Regular liver function tests are important; report any symptoms such as jaundice, severe fatigue, or dark urine promptly.

Q: How should missed doses be managed?
A: If you miss a dose, take it as soon as you remember, unless it is nearly time for your next dose. Do not double doses to make up for a missed one.

Reference: U.S. FDA; NCCN Guidelines; PubMed

Where can I find additional clinical evidence and detailed information about Erlotinib?

For further details on clinical studies, dosing guidelines, and safety monitoring, please refer to:

• U.S. Food and Drug Administration (FDA) Website: FDA.gov
• ClinicalTrials.gov: (e.g., NCT00322452, NCT00121090)
• PubMed: For peer‑reviewed research articles on erlotinib
• World Health Organization (WHO): Guidelines on lung cancer management
• National Comprehensive Cancer Network (NCCN) Guidelines: For NSCLC treatment protocols

Reference: U.S. FDA; ClinicalTrials.gov; NEJM; PubMed; NCCN; WHO

Final Thoughts

Gefitinib is not to be confused with erlotinib; however, Erlotinib (Tarceva®) remains a cornerstone in targeted therapy for non‑small cell lung cancer with EGFR mutations. Its mechanism of action—blocking EGFR tyrosine kinase activity—leads to inhibition of tumor growth and enhanced apoptosis in cancer cells. With careful patient selection, regular monitoring for adverse effects (particularly interstitial lung disease and hepatotoxicity), and appropriate management of drug interactions, erlotinib can significantly improve clinical outcomes. Always consult your healthcare provider to ensure that erlotinib is the appropriate therapy for your condition.

Disclaimer: This guide is intended for educational purposes only and should not replace professional medical advice. Always consult your healthcare provider before initiating or modifying any medication regimen.