Phenobarbital

Phenobarbital may cause excitement, depression, or confusion in elderly or weakened individuals, and excitement in children.

If you have been diagnosed with liver disease or your adrenal glands are not functioning properly, make sure the doctor knows about it. Phenobarbital should be prescribed with caution.

Barbiturates such as phenobarbital may cause you to become tired or less alert. Be careful driving, operating machinery, or doing any activity that requires full mental alertness until you know how you react to this medication.

Possible food and drug interactions when taking Phenobarbital

Phenobarbital may increase the effects of alcohol. Avoid alcoholic beverages while taking phenobarbital.

If phenobarbital is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining phenobarbital with the following:

Antidepressant drugs known as MAO inhibitors, including Nardil and Parnate
Antihistamines such as Benadryl
Blood-thinning medications such as Coumadin
Doxycycline (Doryx, Vibramycin)
Griseofulvin (Fulvicin-P/G, Grifulvin V)
Narcotic pain relievers such as Percocet
Oral contraceptives
Other epilepsy drugs such as Dilantin, Depakene, and Depakote
Other sedatives such as Nembutal and Seconal
Steroids such as Medrol and Deltasone
Tranquilizers such as Xanax and Valium

Special information if you are pregnant or breastfeeding

Barbiturates such as phenobarbital may cause damage to the developing baby during pregnancy. Withdrawal symptoms may occur in an infant whose mother took barbiturates during the last 3 months of pregnancy. If you are pregnant or plan to become pregnant, inform your doctor immediately.

Phenobarbital appears in breast milk and could affect a nursing infant. If phenobarbital is essential to your health, your doctor may advise you to stop breastfeeding until your treatment is finished.

Recommended dosage

ADULTS

Sedation

The usual initial dose of phenobarbital is a single dose of 30 to 120 milligrams. Your doctor may repeat this dose at intervals, depending on how you respond to this medication.