Take XTANDI exactly as your doctor tells you. Take your prescribed dose once a day, at the same time each day. XTANDI can be taken with or without food. Swallow XTANDI capsules or tablets whole with enough water to make sure that you can swallow all of the medicine successfully. Do not chew, dissolve, or open the capsules. Do not cut, crush or chew the tablets. Your doctor may change your dose if needed. Your doctor may also change your pill size or stop treatment if you have swallowing problems., Xtandi (enzalutamide) is a brand-name drug that’s prescribed to treat prostate cancer in certain adults. As with other drugs, Xtandi can cause side effects, such as fatigue, headache, and hot , What are the possible side effects of XTANDI? XTANDI may cause serious side effects including: Seizure. If you take XTANDI, you may be at risk of having a seizure. Avoid activities where a sudden loss of consciousness could seriously harm you or someone else. Tell your doctor right away if you lose consciousness or have a seizure..