Afatinib 40 mg: Complete Guide to Uses, Dosage, Side Effects & Safety

✅ What is Afatinib 40 mg Used For?

Afatinib 40 mg is a targeted cancer therapy indicated for:

1. Non-Small Cell Lung Cancer (NSCLC):

• Specifically for EGFR mutation-positive NSCLC.
• Used as a first-line treatment for patients with:
  • Exon 19 deletions
  • Exon 21 (L858R) substitution mutations

2. Head and Neck Cancer (SCCHN):

• For patients with recurrent or metastatic squamous cell carcinoma of the head and neck who have progressed after platinum-based chemotherapy.

💊 Dosage and Administration

Recommended Dose:

• Afatinib 40 mg orally once daily
• This is the standard starting dose for most adult patients with EGFR-positive NSCLC.

How to Take:

• Take at least 1 hour before or 2 hours after food.
• Swallow tablet whole with water; do not crush or chew.

Dose Adjustments May Be Needed If:

• Patient experiences severe side effects
• Patient has renal impairment
• Managing diarrhea, skin reactions, or liver toxicity

Dose Reduction Steps (if needed):

• From 40 mg → 30 mg → 20 mg (based on tolerability)

❌ Contraindications

• Known hypersensitivity to Afatinib or any excipient.
• Pregnancy or plans for conception.
• Use in patients with severe hepatic impairment (with caution).

🔄 Drug Interactions

Afatinib is a P-glycoprotein (P-gp) substrate:

• P-gp inhibitors (e.g., ritonavir, ketoconazole): May increase Afatinib levels
• P-gp inducers (e.g., rifampin, phenytoin): May reduce effectiveness

To reduce interaction:

• Administer Afatinib at least 6 hours before or after P-gp-modifying drugs.

📋 Side Effects

Common Side Effects:

• Diarrhea
• Rash and acne
• Dry skin
• Mouth ulcers (stomatitis)
• Nail inflammation (paronychia)
• Nausea and vomiting
• Fatigue
• Decreased appetite

Serious Adverse Effects:

• Interstitial lung disease (ILD)
• Liver dysfunction
• Severe diarrhea leading to dehydration
• Eye disorders (keratitis, ulceration)
• Heart rhythm abnormalities (rare)

🤰 Use in Pregnancy and Breastfeeding

• Pregnancy Category D: Positive evidence of human fetal risk.
• Not recommended in breastfeeding—discontinue nursing or the drug based on clinical need.

🧪 Monitoring Parameters

• Liver function tests
• Skin assessment
• Diarrhea frequency
• Signs of lung toxicity (ILD)
• Renal function
• Electrolytes and cardiac rhythm (if at risk)

🧊 Storage Instructions

• Store below 30°C (86°F)
• Keep away from moisture and direct light
• Store in original packaging
• Keep out of reach of children