Phenobarbital

You should not take more than 400 milligrams during a 24-hour period.

Daytime Sedation

The usual dose is 30 to 120 milligrams a day, divided into 2 to 3 doses.

To Induce Sleep

The usual dose is 100 to 200 milligrams.

Anticonvulsant Use

Phenobarbital dosage must be individualized on the basis of specific laboratory tests. Your doctor will determine the exact dose best for you. The usual dose is 60 to 200 milligrams daily.

CHILDREN

Anticonvulsant Use

The phenobarbital dosage must be individualized on the basis of specific laboratory tests. Your doctor will determine the exact dose best for your child.

The usual dose is 3 to 6 milligrams per 2.2 pounds of body weight per day.

DOSAGE ADJUSTMENT

People who are elderly or weak may be prescribed a lower dose. People who have liver or kidney disease may also require a lower dose of phenobarbital.

Overdosage

Barbiturate overdose can be fatal. If you suspect an overdose, seek medical treatment immediately.

• Symptoms of phenobarbital overdose may include:
  Congestive heart failure, diminished breathing, extremely low body temperature, fluid in lungs, involuntary eyeball movements, irregular heartbeat, kidney failure, lack of muscle coordination, low blood pressure, poor reflexes, skin reddening or bloody blisters, slowdown of the central nervous system