Drug Interaction Report

Using erdafitinib together with etidronate may alter the levels of phosphate in the blood, which may affect the dose of erdafitinib. Your doctor will check your blood phosphate level between 14 and 21 days after starting treatment with erdafitinib and then monthly, and may change your dose if necessary. Talk to your doctor if you have any questions or concerns. Contact your doctor as soon as possible if you develop signs and symptoms of high phosphate levels in the blood (hyperphosphatemia) such as muscle cramps, convulsions, tingling or numbness around the mouth, and bone pain. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Food, especially calcium-containing food such as dairy products, significantly decreases the absorption of etidronate. For at least the first 2 hours after taking etidronate, do not eat or drink anything other than plain water, and do not take any other medicines including vitamins or mineral supplements which are high in metals such as calcium, iron, magnesium, or aluminum. Use only plain water (not mineral water) when taking etidronate tablets.

Etidronate and multivitamin with minerals should not be taken orally at the same time. Products that contain magnesium, aluminum, calcium, iron, and/or other minerals may interfere with the absorption of etidronate into the bloodstream and reduce its effectiveness. You should take multivitamin with minerals at least 2 hours before or 2 hours after the etidronate dose. Talk to a healthcare professional if you are not sure whether a product contains something that could potentially interact with your medication or if you have questions on how to take this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.