afatinib dimaleate: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
afatinib dimaleate: clinical details
Prescribing considerations
- Initiation and supervision require experience with anticancer therapy; establish EGFR mutation status using a validated method for the mutation-positive indication.
- Plan proactive management of diarrhoea and skin toxicity, with prompt treatment and review for interruption or modification by the oncology specialist.
- Monitor more closely where exposure may be higher, including lower body weight, female sex and renal impairment.
- Treatment is not recommended in severe hepatic impairment, end-stage renal impairment or dialysis because evidence is insufficient.
- Review gastrointestinal ulceration, diverticular disease, bowel metastases and concurrent corticosteroids, NSAIDs or anti-angiogenic agents because these may increase perforation risk.
- Use caution with previous keratitis, severe dry eye, contact-lens use, interstitial lung disease or significant cardiac disease.
Contraindications and cautions
- Hypersensitivity to afatinib or any tablet excipient.
- The selected tablet contains lactose and should not be used in rare hereditary galactose intolerance, total lactase deficiency or glucose-galactose malabsorption.
Monitoring
- Assess diarrhoea, hydration, skin, mouth, nail and eye toxicity promptly.
- Check renal function and electrolytes when diarrhoea, vomiting or dehydration occurs.
- Monitor liver function, particularly with pre-existing liver disease or worsening clinical features.
- Investigate acute or unexplained respiratory deterioration immediately and interrupt treatment while interstitial lung disease is assessed.
- Consider baseline and on-treatment left-ventricular function assessment in patients with cardiac risk factors or relevant symptoms.
- Assess treatment response and tolerability at specialist oncology reviews.
Clinical pharmacology
Afatinib covalently and irreversibly inhibits signalling from EGFR, HER2, ErbB3 and ErbB4 receptor combinations. It undergoes little enzyme-mediated metabolism, is eliminated mainly in faeces and is a substrate of P-glycoprotein and BCRP.
Formulation and product differences
- The selected product is a film-coated tablet containing afatinib as dimaleate and lactose.
- The tablet may be swallowed whole or dispersed in still water when swallowing whole tablets is not possible.
- Keep it in the original packaging to protect it from moisture and light.
afatinib dimaleate preparations and strengths
Tablet
Route: Oral
Strengths: 20 mg, 30 mg, 40 mg
afatinib dimaleate interactions
Tell the oncology team and pharmacist about prescribed, non-prescription and herbal products. Important examples include:
Strong P-glycoprotein inhibitors, including ritonavir, itraconazole, erythromycin, verapamil, amiodarone, ciclosporin and tacrolimus
These may increase afatinib exposure and adverse effects; the specialist may need to separate administration times.
Strong P-glycoprotein inducers, including rifampicin, carbamazepine, phenytoin and phenobarbital
These may lower afatinib exposure and reduce its effect.
St John's wort
This herbal product may lower afatinib exposure and should be discussed with the oncology team before use.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.