Drug Interaction Report

PHENobarbital may reduce the blood levels and effects of progesterone. If you are using low-dose oral contraceptives, you may have an increased risk of breakthrough bleeding and unintended pregnancy. You should discuss the use of alternative or additional methods of birth control with your healthcare provider. If you take hormone replacement for menopause, notify your doctor if your medication is no longer controlling your symptoms or you experience abnormal bleeding. You may need a dose adjustment or more frequent monitoring by your doctor 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.

Grapefruit juice may increase the blood levels of certain medications such as progesterone. You may want to limit your consumption of grapefruit and grapefruit juice during treatment with progesterone. However, if you have been regularly consuming grapefruit or grapefruit juice with the medication, then it is advisable for you to talk with your doctor before changing the amounts of these products in your diet, as this may alter the effects of your medication. Contact your doctor if your condition changes or you experience increased side effects. Orange juice is not expected to interact.