Afatinib [Specialist drug]

How it works

It irreversibly inhibits the ErbB family of receptor tyrosine kinases, including EGFR, blocking downstream signalling that drives tumour growth.

Prescribing in practice

• Diarrhoea is very common and can be severe; manage early with antidiarrhoeals and fluids and modify the dose to prevent dehydration and renal impairment.
• Severe skin reactions, including rash and stomatitis, and rarely interstitial lung disease can occur and may require treatment interruption.
• It is affected by P-glycoprotein interactions, so review concomitant inhibitors and inducers as described in the SPC.

Monitoring

Monitor for diarrhoea, skin and mucosal toxicity, hydration and renal function, and for respiratory symptoms suggestive of interstitial lung disease.

Counselling the patient

• Begin antidiarrhoeal treatment promptly at the first loose stool and keep well hydrated.
• Report severe rash, mouth ulcers, or new breathlessness.
• Take the tablets on an empty stomach and avoid food close to the dose as advised.

Evidence & guidelines

NICE technology appraisals support afatinib for EGFR mutation-positive non-small-cell lung cancer.