Erdafitinib, an FGFR inhibitor, may cause various adverse reactions when used to treat urothelial carcinoma with FGFR gene abnormalities.
I. Common Side Effects of Erdafitinib
1. Ocular Toxicity
(1) Retinopathy of Premature Retinopathy (CSR/RPED): Incidence 25%, median onset 50 days, 3% grade 3 (involving central visual field).
(2) Dry Eye Syndrome: Incidence 28%, 6% grade 3.
2. Hyperphosphatemia: Incidence 76%, median onset 20 days, 32% of patients require phosphate binders.
3. Gastrointestinal Reactions
(1) Stomatitis (56%), diarrhea (47%), dry mouth (45%), constipation (28%).
(2) Abdominal pain (23%), nausea (21%).
4. Skin and Appendage Reactions
(1) Onycholysis (41%), dry skin (34%), palmoplantar erythema syndrome (26%).
(2) Hair loss (26%), nail discoloration (11%).
5. Other Frequent Reactions
(1) Fatigue (54%), taste disturbance (37%), hyponatremia (40%).
(2) Musculoskeletal pain (20%), urinary tract infection (17%).
II. Strategies for Alleviating Erdafitinib Side Effects
1. Management of Ocular Symptoms
(1) Prevention: Use artificial tears daily (at least every 2 hours).
(2) Monitoring: Monthly ophthalmological examination (including OCT) for the first 4 months of treatment, then every 3 months thereafter.
(3) Management: Discontinue use if symptoms such as blurred vision occur; resume use at a reduced dose after recovery.
2. Hyperphosphatemia Control
(1) Diet: Restrict phosphorus intake (600-800 mg/day).
(2) Intervention: Serum phosphorus 7 mg/dL: Use phosphate binders and discontinue medication; 9 mg/dL: Reduce medication dosage.
3. Stomatitis Management
(1) Gargle with analgesic solution, avoid spicy foods.
(2) For grade 3 symptoms, discontinue medication until recovery to grade 1.
4. Skin Reaction Management
(1) Onycholysis: Keep nails clean and dry, avoid trauma.
(2) Palmoplantar erythema syndrome: Use urea ointment, reduce dosage in severe cases.
III. Erdafitinib Storage Requirements
1. Environmental Conditions
(1) Store at 20-25°C (68-77°F).
(2) Short-term storage is permissible at 15-30°C (59-86°F).
2. Packaging Characteristics
(1) Child-proof bottle.
(2) Three sizes: 3mg (yellow), 4mg (orange), and 5mg (brown) tablets.
3. Precautions
(1) Avoid humid environments.
(2) Reseal after opening.
