Erdafitinib is used to treat urothelial cancer (cancer of the lining of the bladder and other parts of the urinary tract) that spread to nearby tissues or other parts of the body that cannot be removed by surgery and has worsened during or after being treated with other chemotherapy medications. Erdafitinib is in a class of medications called kinase inhibitors. It works by blocking the action of an abnormal protein that signals cancer cells to multiply. This helps slow or stop the spread of cancer cells.

Side Effects Of Erdafitinib

Erdafitinib may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • nausea
  • diarrhea
  • vomiting
  • constipation
  • sores on lips, mouth, or throat
  • dry mouth
  • changes in taste
  • abdominal pain
  • decreased appetite
  • weight loss
  • unusual hair thinning or hair loss
  • fever
  • muscle or joint pain
  • burning during urination
  • fatigue or tiredness
  • shortness of breath

Some side effects can be serious. If you experience any of these symptoms , stop taking erdafitinib and call your doctor immediately:

  • blurred vision, loss of vision, or other visual changes
  • nail problems or changes
  • itchy, dry, or cracked skin
  • rash
  • swelling, pain, redness, or peeling of skin on the palms and soles of the feet

Erdafitinib may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

Warnings & Precautions

Before taking erdafitinib:

  • tell your doctor and pharmacist if you are allergic to erdafitinib, any other medications, or any of the ingredients in erdafitinib tablets. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: antifungals such as fluconazole (Diflucan), itraconazole (Sporonox, Onmel, Tolsura), and ketoconazole; carbamazepine (Carbatrol, Equetro, Tegretol, others); clarithromycin; medications for human immunodeficiency virus (HIV) such as efavirenz (Sustiva, in Atripla), indinavir (Crixivan), nelfinavir (Viracept), nevirapine (Viramune), ritonavir (Norvir, in Kaletra, in Viekira), and saquinavir (Fortovase, Invirase); metformin (Fortamet, Glucophage, in Actoplus Met, others); nefazodone; phenobarbital; phenytoin (Dilantin, Phenytek;), rifampin (Rifadin, Rimactane, in Rifater); and telithromycin (Ketek). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with erdafitinib, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
  • tell your doctor if you have ever been told that you have high blood levels of phosphorus or if you have or have ever had eye or vision problems, or kidney or liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or if you plan on fathering a child. If you are female, you will need to take a pregnancy test before you start treatment and use birth control to prevent pregnancy during your treatment and for 1 month after your final dose. If you are a male, you and your partner should use birth control during your treatment with erdafitinib and for 1 month after your final dose. Talk to your doctor about birth control methods that you can use during your treatment. If you or your partner become pregnant while taking erdafitinib, call your doctor immediately. Erdafitinib may harm the fetus.
  • tell your doctor if you are breastfeeding. You should not breastfeed while you are taking erdafitinib and for 1 month after the final dose.
  • you should know that this medication may decrease fertility in women. Talk to your doctor about the risks of taking erdafitinib.
  • you should know that this medication may cause dry eyes and other eye problems, which may be serious. Your doctor may tell you to use artificial tears or lubricant eye drops during your treatment with erdafitinib.

Erdafitinib Dosage

Erdafitinib comes as a tablet to take by mouth. It is usually taken once a day with or without food. Take erdafitinib at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take erdafitinib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole; do not split, chew, or crush them.

If you vomit after taking erdafitinib, do not take another dose. Continue your regular dosing schedule.

Your doctor may decrease your dose or temporarily or permanently stop your treatment if you experience certain side effects. Be sure to tell your doctor how you are feeling during your treatment with erdafitinib. Do not stop taking erdafitinib without talking to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.


Keep all appointments with your doctor, eye doctor, and the laboratory. Your doctor will order certain lab tests to check your body’s response to erdafitinib.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.