Makindo Medical Notes

Erlotinib

💊 Erlotinib (Tarceva) is an oral EGFR tyrosine kinase inhibitor (TKI) used in certain cancers. It specifically targets tumour cells with dysregulated EGFR signalling, slowing growth and proliferation. Always check the BNF for up-to-date prescribing details.

⚙️ Mode of Action

• 🧬 Reversible binding to the ATP-binding site of the EGFR tyrosine kinase.
• 🚫 Inhibits downstream signalling pathways → reduced proliferation, angiogenesis, and metastasis.
• Particularly effective in tumours with activating EGFR mutations.

📋 Indications / Dose

• 👩‍⚕️ Non-Small Cell Lung Cancer (NSCLC) with EGFR mutation.
• 🧪 Occasionally used in pancreatic cancer (with gemcitabine).
• 💊 Oral, once daily dosing — see BNF for details.

🔗 Interactions

• ⚠️ CYP3A4 inducers/inhibitors affect plasma levels.
• 🚬 Smoking induces metabolism → ↓ plasma concentration and efficacy.
• Check BNF for full list.

⚠️ Cautions

• 💢 Resistance typically develops after 8–12 months due to secondary EGFR mutations (e.g. T790M).
• 🫁 Interstitial lung disease (rare but potentially fatal).
• 📉 Monitor for hepatotoxicity and renal impairment.

🚫 Contraindications

• See BNF

💊 Side Effects

• 💥 Acneiform rash (may correlate with efficacy).
• 💩 Diarrhoea (can be severe).
• 🤢 Nausea, anorexia, fatigue.
• 🫁 Rare: interstitial lung disease.
• See BNF for full list.

📚 Case Example

👨 A 62-year-old ex-smoker with advanced NSCLC is found to have an EGFR exon 19 deletion. He is started on oral erlotinib. Two weeks later, he develops a papulopustular rash on the face and torso 💥. ✅ This is explained as a common side effect — and paradoxically a good prognostic marker for drug activity.

🔗 References

• BNF: Erlotinib
• Fakih M. Erlotinib in the treatment of advanced non-small cell lung cancer. Clin Med Insights Oncol. 2010.
• Herbst RS et al. Gefitinib and erlotinib in lung cancer. Oncologist. 2005.

📅 Revisions

• Last updated: Check BNF and NICE for current oncology guidelines.