What the label lists and what reports show
Afatinib side effects
Afatinib's FDA label: “Most common adverse reactions (≥20%) were diarrhea, rash/acneiform dermatitis, stomatitis, paronychia, dry skin, decreased appetite, nausea, vomiting, pruritus ( 6.1 ).” FAERS holds 6,587 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is diarrhoea (2,121 reports).
- Generic listed
Check it at the source: the afatinib FDA label on DailyMed (effective November 13, 2025, Boehringer Ingelheim Pharmaceuticals, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of GILOTRIF?GILOTRIF may cause serious side effects, including: diarrhea. Diarrhea is common with GILOTRIF and may sometimes be severe. Severe diarrhea can cause loss of too much body fluid (dehydration) and kidney problems that can sometimes lead to death. During your treatment with GILOTRIF, your healthcare provider should prescribe medicines to treat diarrhea. Take this medicine exactly as your healthcare provider tells you to. Tell your healthcare provider if you have diarrhea. Get medical attention right away if your diarrhea does not go away or becomes severe. skin reactions. GILOTRIF can cause redness, rash, and acne. It is important to get treatment for skin reactions as soon as you notice them. Take medicines to help skin reactions exactly as your healthcare provider tells you to. […]
Source: FDA drug label, Boehringer Ingelheim Pharmaceuticals, Inc., effective November 13, 2025 (SPL set fd638e5e-8032-e7ca-0179-95e96ab5d387), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (≥20%) were diarrhea, rash/acneiform dermatitis, stomatitis, paronychia, dry skin, decreased appetite, nausea, vomiting, pruritus ( 6.1 ).
Table 1 Adverse Reactions Reported in ≥10% of GILOTRIF-Treated Patients in LUX-Lung 3*
| Reaction | All Grades (%) | Grade 3 † (%) | All Grades (%) | Grade 3 † (%) |
|---|---|---|---|---|
| Diarrhea | 96 | 15 | 23 | 2 |
| Stomatitis 1 | 71 | 9 | 15 | 1 |
| Cheilitis | 12 | 0 | 1 | 0 |
| Rash/acneiform dermatitis 2 | 90 | 16 | 11 | 0 |
| Pruritus | 21 | 0 | 1 | 0 |
| Dry skin | 31 | 0 | 2 | 0 |
| Paronychia 3 | 58 | 11 | 0 | 0 |
| Cystitis | 13 | 1 | 5 | 0 |
| Epistaxis | 17 | 0 | 2 | 1 |
| Rhinorrhea | 11 | 0 | 6 | 0 |
| Weight decreased | 17 | 1 | 14 | 1 |
| Pyrexia | 12 | 0 | 6 | 0 |
| Conjunctivitis | 11 | 0 | 3 | 0 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are described elsewhere in the labeling: Diarrhea [see Warnings and Precautions (5.1) ] Bullous and Exfoliative Skin Disorders [see Warnings and Precautions (5.2) ] Interstitial Lung Disease [see Warnings and Precautions (5.3) ] Hepatic Toxicity [see Warnings and Precautions (5.4) ] Gastrointestinal Perforation [see Warnings and Precautions (5.5) ] Keratitis [see Warnings and Precautions (5.6) ] Most common adverse reactions (≥20%) were diarrhea, rash/acneiform dermatitis, stomatitis, paronychia, dry skin, decreased appetite, nausea, vomiting, pruritus ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Boehringer Ingelheim Pharmaceuticals, Inc. at (800) 542-6257 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. …
Source: FDA drug label, Boehringer Ingelheim Pharmaceuticals, Inc., effective November 13, 2025 (SPL set fd638e5e-8032-e7ca-0179-95e96ab5d387), via openFDA; the full label on DailyMed
What do FAERS reports show?
6,587 reports list afatinib among the medicines taken, each a report of something that happened, not proof the medicine caused it; 1,464 are coded as a death and 2,084 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 16 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Afatinib: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions