While Taking This Drug, Observe the Following

Foods: No restrictions. Eat liberally of foods rich in folic acid: fortified breakfast cereals, liver, legumes, green leafy vegetables.

Beverages: No restrictions. May be taken with milk or fruit juices.

Alcohol: Avoid completely. Alcohol can increase greatly the sedative and depressant actions of this drug on brain functions.

Tobacco Smoking: May enhance the sedative effects of this drug and in­crease drowsiness.

Marijuana Smoking: Increased drowsiness, unsteadiness; significantly im­paired mental and physical performance.

Other Drugs Phenobarbital may increase the effects of

• all other drugs with sedative effects, and cause excessive sedation.
Phenobarbital may decrease the effects of

• anticoagulants (Coumadin, etc.), and require dosage adjustments.

• certain beta blockers (Inderal, Lopressor), and reduce their effective­
ness.

• cortisonelike drugs.

• doxycycline (Vibramycin), and reduce its effectiveness.

• griseofulvin (Fulvicin, etc.), and reduce its effectiveness.

• oral contraceptives, and reduce their effectiveness in preventing preg­
nancy.

• quinidine (Quinaglute, etc.), and reduce its effectiveness.

• theophyllines (Aminophyllin, Theo-Dur, etc.), and reduce their an­
tiasthmatic effectiveness.

Phenobarbital taken concurrently with

• phenytoin (Dilantin) may alter phenytoin blood levels: a high pheno­
barbital level will increase the phenytoin level; a low phenobarbital
level will decrease the phenytoin level. Periodic determination of blood
levels of both drugs is advised.

The following drugs may increase the effects of phenobarbital

• valproic acid (Depakene).

Driving, Hazardous Activities: This drug may cause drowsiness and may

impair mental alertness, judgment, physical coordination and reaction

time. Restrict activities as necessary. Aviation Note: The use of this drug is a disqualification for piloting.

Consult a designated Aviation Medical Examiner. Exposure to Sun: Use caution until sensitivity has been determined. This

drug may cause photosensitivity.

Exposure to Cold: Observe the elderly for possible hypothermia while taking this drug.

Discontinuation: If used as an anticonvulsant, this drug must not be discontinued abruptly. Sudden withdrawal can precipitate status epilepticus (repetitive seizures). Gradual reduction in dosage should be made over a period of 3 months. Total drug withdrawal may be attempted after a period of 3 to 5 years without a seizure. However, seizures are likely to recur in 40% of adults and in 20% to 30% of children.