If phenobarbital is taken with certain other medicines, the effects of both could be increased, decreased, or altered. Even other seizure medicines may be affected: Phenobarbital causes a decrease blood levels of:

• Tegretol, Carbatrol (carbamazepine)
• Depakote, Depakene (valproic acid)
• Lamictal
• Zonegran
• Gabitril

Medications often used for other disorders are also affected. It is especially important to check with your doctor before taking any of these:

• Antidepressants
• Allergy medicines
• Coumadin (warfarin)
• Theophylline
• Tagamet (cimetidine)
• Oral contraceptives (birth control pills)
• Narcotic pain relievers such as Percocet
• Sedatives such as Nembutal and Seconal
• Steroids such as Medrol and Deltasone
• Tranquilizers such as Xanax and Valium

Reviewed February 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.