Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Balversa (Erdafitinib). If you are concerned about side effects, discuss the risks and benefits of Balversa (Erdafitinib) with your doctor.

The following side effects have been reported by at least 1% of people taking Balversa (Erdafitinib). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• changed sense of taste
• Constipation
• decreased appetite
• Diarrhea
• discoloured nails
• dry eyes
• Dry Mouth, nose, skin
• fatigue
• hair loss
• infected skin around the nail
• itchy skin rash
• muscle pain
• nausea
• sore throat
• stomach pain
• vaginal dryness
• vomiting
• watery eyes
• weakness
• weight loss

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• blood in the urine
• dry eyes
• Fever
• mouth sores
• signs of Anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• skin or nail problems (e.g., nail pain, cracked skin, very dry skin, bleeding under the nail, nail separation from the bed)
• skin rash
• swelling or peeling skin of the hands and feet
• symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)
• vision problems (e.g., blurred vision, vision loss, cloudy vision)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Balversa (Erdafitinib).

3 mg
Each yellow, round, biconvex, film-coated tablet, debossed with "3" on one side and "EF" on the other side, contains 3 mg of Balversa (Erdafitinib). Nonmedicinal ingredients: croscarmellose sodium, magnesium stearate (from vegetable source), mannitol, meglumine, and microcrystalline cellulose; film-coating: glycerol monocaprylocaprate Type I, iron oxide yellow, polyvinyl alcohol partially hydrolyzed, sodium lauryl sulfate, talc, and titanium dioxide.

4 mg
Each orange, round, biconvex, film-coated tablet, debossed with "4" on one side and "EF" on the other side, contains 4 mg of Balversa (Erdafitinib). Nonmedicinal ingredients: croscarmellose sodium, magnesium stearate (from vegetable source), mannitol, meglumine, and microcrystalline cellulose; film-coating: glycerol monocaprylocaprate Type I, iron oxide yellow, iron oxide red, polyvinyl alcohol partially hydrolyzed, sodium lauryl sulfate, talc, and titanium dioxide.

5 mg
Each brown, round, biconvex, film-coated tablet, debossed with "5" on one side and "EF" on the other side, contains 5 mg of Balversa (Erdafitinib). Nonmedicinal ingredients: croscarmellose sodium, magnesium stearate (from vegetable source), mannitol, meglumine, and microcrystalline cellulose; film-coating: ferrosoferric oxide/iron oxide black, glycerol monocaprylocaprate Type I, iron oxide yellow, iron oxide red, polyvinyl alcohol partially hydrolyzed, sodium lauryl sulfate, talc, and titanium dioxide.

Do not take Balversa (Erdafitinib) if you are allergic to Balversa (Erdafitinib) or any ingredients of the medication.

There may be an interaction between Balversa (Erdafitinib) and any of the following:

• Abiraterone acetate
• Aliskiren
• aluminum hydroxide
• alpha-blockers (e.g., Alfuzosin, Doxazosin, Silodosin, Tamsulosin)
• amantadine
• Amiloride
• antiarrhythmics (e.g., amidarone, Disopyramide, Dronedarone, procainamide, quinidine)
• anticancer medications (e.g., Busulfan, Cabazitaxel, Docetaxel, Doxorubicin, Etoposide, Ifosfamide, Irinotecan, Vincristine)
• Apalutamide
• Aprepitant
• Aripiprazole
• "azole" antifungals (e.g., fluconazole, itraconazole, ketoconazole, Voriconazole)
• benzodiazepines (e.g., Chlordiazepoxide, Clonazepam, Diazepam, Lorazepam)
• Bicalutamide
• Bisoprolol
• Bosentan
• Buprenorphine
• Buspirone
• Calcitriol
• calcium carbonate
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• Carvedilol
• cetirizine
• chloroquine
• Cobicistat
• Colchicine
• conivaptan
• Cyclosporine
• dabigatran
• Dantrolene
• Dapsone
• Darifenacin
• Deferasirox
• Dexamethasone
• Digoxin
• Eliglustat
• Enzalutamide
• estrogens (e.g., conjugated estrogen, Estradiol, ethinyl estradiol)
• Everolimus
• Fesoterodine
• Flibanserin
• Flutamide
• "gliptin" Diabetes medications (e.g., Linagliptin, Saxagliptin, Sitagliptin)
• grapefruit juice
• H2-receptor blockers (e.g., Cimetidine, Famotidine, Ranitidine)
• Haloperidol
• Hepatitis C antivirals (e.g., daclatasvir, dasabuvir, ombitasvir, paritaprevir)
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• Hydrocortisone
• ivermectin
• Leflunomide
• Lomitapide
• Loperamide
• Loratadine
• Losartan
• lumacaftor
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• magnesium hydroxide
• maraviroc
• Mefloquine
• Memantine
• Metformin
• Methadone
• mifepristone
• Mirtazapine
• Mitotane
• Modafinil
• nitrates (e.g., isosorbide dinitrate, isosorbide mononitrate)
• Nadolol
• Naloxegol
• Ondansetron
• Oxycodone
• phosphate supplements
• Pimozide
• Pindolol
• praziquantel
• Primaquine
• progestins (e.g., Dienogest, Levonorgestrel, medroxyprogesterone, Norethindrone)
• other protein kinase inhibitors (e.g., Bosutinib, Crizotinib, Dabrafenib, imatinib, Nilotinib, Pazopanib)
• proton pump inhibitors (e.g., Lansoprazole, Omeprazole)
• Quetiapine
• quinine
• Repaglinide
• rifabutin
• rifampin
• rilpivirine
• Rivaroxaban
• Romidepsin
• St. John's wort
• seizure medications (e.g., Carbamazepine, Eslicarbazepine, Phenobarbital, Phenytoin, primidone, zonisamide)
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• Sildenafil
• Sirolimus
• Solifenacin
• "statin" anticholesterol medications (e.g., Atorvastatin, Lovastatin, Simvastatin)
• Stiripentol
• Tacrolimus
• Tamoxifen
• Tetracycline
• Ticagrelor
• Ticlopidine
• Tocilizumab
• Tolterodine
• Tolvaptan
• Tramadol
• Trazodone
• tricyclic antidepressants (e.g., Amitriptyline, Clomipramine, Desipramine, Trimipramine)
• Ulipristal
• Varenicline
• Zolpidem
• Zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Balversa (Erdafitinib). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Balversa (Erdafitinib).

Eye problems: People taking Balversa (Erdafitinib) may experience eye problems and vision changes. If you experience changes to your vision such as cloudiness, blurred vision or vision loss, contact your doctor immediately.

Phosphorus levels: Balversa (Erdafitinib) can cause higher than normal levels of phosphate in the blood. Your doctor will test for the amount of phosphate in your blood with blood tests while you are taking Balversa (Erdafitinib).

Pregnancy: Balversa (Erdafitinib) should not be taken during pregnancy. Balversa (Erdafitinib) may cause severe harm to a developing baby if it is taken by the mother while she is pregnant. Female partners of men taking Balversa (Erdafitinib) should not become pregnant. Both females and males must use a reliable method of birth control (e.g., condoms, birth control pill) during treatment and for at least 3 months after treatment is finished. If you become pregnant while taking Balversa (Erdafitinib), contact your doctor immediately.

Breast-feeding: Balversa (Erdafitinib) may pass into breast milk. If you are a breast-feeding mother and are taking Balversa (Erdafitinib), it may affect your baby. Due to the potential for serious harm to a baby if they are exposed to Balversa (Erdafitinib), breast-feeding mothers are advised not use Balversa (Erdafitinib).

Children: The safety and effectiveness of using Balversa (Erdafitinib) have not been established for children.