Drug Interaction Report

Using risedronate together with pemigatinib may increase the levels of phosphate in the blood, which may increase your risk of high phosphate levels (hyperphosphatemia), and a buildup of minerals such as calcium in different tissues in your body. Your doctor will check your blood phosphate level regularly when your first start treatment with pemigatinib and regularly throughout treatment. They may recommend changes in your diet, phosphate-lowering therapy, and/or change your dose of pemigatinib 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.

Pemigatinib may be taken with or without food. Do not consume grapefruit, grapefruit juice, or any supplements that contain grapefruit extract during treatment with pemigatinib unless directed otherwise by your doctor. Grapefruit juice can increase the blood levels of pemigatinib. This may increase the frequency and severity of serious side effects such as elevated phosphate levels in the blood (which can eventually lead to low blood calcium levels; calcium deposits in the skin, muscles, and other tissues; anemia; muscle cramps; seizures; and irregular heart rhythm), eye and vision problems, joint pain, mouth sores and inflammation, hair loss, diarrhea, nausea, vomiting, and constipation. Talk to your doctor if you have any questions or concerns. 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 may reduce the absorption of risedronate, which may lead to lower blood levels of the medication and possibly reduced effectiveness. You should take risedronate first thing in the morning, at least 30 minutes before you eat or drink anything or take any other medication. Take each dose with a full glass (6 to 8 ounces) of water, and use only plain water (not mineral or vitamin water). Do not take risedronate if you cannot sit upright or stand for at least 30 minutes. Because risedronate can cause irritation and ulcer in the stomach or esophagus (the tube that connects your mouth and stomach), you will need to stay upright for at least 30 minutes after taking this medication. Talk to your doctor or pharmacist 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.