Drug Interaction Report

Using regorafenib together with loncastuximab tesirine may increase the risk of serious and potentially life-threatening infections, as well as increase the risk of side effects that affect your bone marrow function, resulting in low numbers of different types of blood cells. You may be more likely to develop anemia, bleeding problems, or infections due to low blood cell counts. You should seek medical attention if you develop paleness, fatigue, dizziness, fainting, unusual bruising or bleeding, or if you develop signs and symptoms of infection such as fever, chills, diarrhea, sore throat, muscle aches, shortness of breath, blood in phlegm, weight loss, red or inflamed skin, body sores, and pain or burning during urination, during or after treatment with these drugs. Talk to your doctor if you have any questions or concerns. Your doctor may already be aware of the risks, but has determined that this is the best course of treatment for you and has taken appropriate precautions and is monitoring you closely for any potential complications. 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.

Depending on the amount of fat, food may help the absorption of regorafenib. You should take it with a low-fat breakfast at the same time everyday to maintain consistent blood levels and effects. Examples of a low-fat breakfast include: 2 slices of white toast with 1 tablespoon of low-fat margarine and 1 tablespoon of jelly, plus 8 ounces of skim milk (319 calories; 8.2 g fat); or 1 cup of cereal, 8 ounces of skim milk, 1 slice of toast with jam, apple juice, and 1 cup of coffee or tea (520 calories; 2 g fat). Avoid consuming grapefruit or grapefruit juice during treatment, as it may alter the blood levels and effects of the 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.