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 this medication.
Abnormal heart rhythms: This medication can cause abnormal heart rhythms. Certain medications (e.g., sotalol, quinidine, thioridazine, chlorpromazine, droperidol, pimozide, gatifloxacin, moxifloxacin, mefloquine, pentamidine, arsenic trioxide, dolasetron mesylate, probucol, tacrolimus) can increase the risk of a type of abnormal heart rhythm called QT prolongation, and should not be used in combination with enzalutamide. You are more at risk for this type of abnormal heart rhythm and its complications if you:
- are female
- are older than 65 years of age
- have a family history of sudden cardiac death
- have a history of heart disease or abnormal heart rhythms
- have a slow heart rate
- have congenital prolongation of the QT interval
- have diabetes
- have low potassium, magnesium, or calcium levels
- have nutritional deficiencies
- have had a stroke
If you have heart disease and abnormal heart rhythms, or if you are taking certain medications (e.g., verapamil, atazanavir), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Blood disorders: This medication can cause the levels of certain blood cells to drop. This may lead to problems with blood clotting, or the immune system. Contact your doctor immediately if you develop a fever, chills, easy bruising, or bleeding (symptoms may include black and tarry stools, blood in the urine, or cuts that won't stop bleeding) while taking this medication. Your doctor will arrange periodic blood testing to monitor various blood components.
Blood pressure: Enzalutamide may cause high blood pressure. Your doctor should monitor your blood pressure regularly while you are taking this medication.
Posterior Reversible Encephalopathy Syndrome: Very rarely, this medication can cause a reversible brain problem called PRES (posterior reversible encephalopathy syndrome). If you develop a seizure, headache, weakness, confusion, loss of vision, or other vision changes while using this medication, get immediate medical attention.
Reduced alertness: Enzalutamide may affect the mental abilities needed to drive or operate machinery, such as concentration, problem solving and focused attention. Avoid driving, operating machinery, or performing other hazardous tasks until you have determined how this medication affects you.
Seizures: There have been reports of seizures occurring with enzalutamide. Seizures are more likely to occur when higher doses of this medication are taken or in people who have been previously treated with docetaxel. If you have a history of epilepsy or medical conditions that increase the risk of seizures, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Pregnancy: Enzalutamide should not be used by women. It is not known if enzalutamide is found in semen. If you are engaged in sexual activity with a pregnant woman, a condom should be used. If you are engaged in sexual activity with a woman who may become pregnant, you should use a condom and a second effective method of birth control. Condoms must be used during treatment with enzalutamide and for 3 months after treatment has ended to avoid possible contact between a developing fetus and the medication. To prevent accidental exposure to enzalutamide, women who handle these tablets should wear gloves.
Breast-feeding: Enzalutamide should not be used by women. It is not known if enzalutamide passes into breast milk. To prevent accidental exposure to enzalutamide, women who handle these tablets should wear gloves.
Children: The safety and effectiveness of using this medication have not been established for children.