Drug Interaction Report

PHENobarbital can significantly reduce the blood levels of abiraterone, which may make the medication less effective in treating your condition. Using PHENobarbital with abiraterone may also increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. 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.

Ask your doctor before using PHENobarbital together with ethanol (alcohol), this can add to dizziness, drowsiness and other side effects of PHENobarbital. Be careful if you drive or do activities that require you to be awake and alert. Talk with your doctor before using any medications together, or drinking alcohol with PHENobarbital. 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.

This interaction does not apply to abiraterone acetate (Yonsa) 125 mg tablets, which can be taken with or without food.

Taking abiraterone with food increases the amount of medicine that gets absorbed by the body for certain formulations. This may increase the risk of side effects such as high blood pressure, water retention, and a condition called hypokalemia (low blood potassium), which in severe cases can lead to muscle weakness, paralysis, breathing and swallowing difficulties (due to muscle paralysis), and irregular heart rhythm. You should take abiraterone once a day on an empty stomach. No food should be eaten for at least two hours before and one hour after taking abiraterone. Let your doctor know if you experience nausea, vomiting, constipation, abdominal cramping, confusion, dizziness, lightheadedness, fainting, muscle weakness, muscle cramps, numbness or tingling, rapid heartbeat, chest pain, and/or swelling in the legs or feet, as these may be symptoms of hypokalemia or excessive effects of abiraterone. 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.