Afatinib-Induced Acute Fatal Pneumonitis in Metastatic Lung Adenocarcinoma.

Afatinib is an oral tyrosine kinase inhibitor (TKI) that inhibit Endothelial Growth Factor Receptor (EGFR), Human Epidermal Growth Factor Receptor 2 (HER2), and HER4. The common side effects of EGFR TKI are rash, acne, diarrhea, stomatitis, pruritus, nausea, and loss of appetite. Drug induced pneumonitis is the less common adverse effects of EGFR TKI.