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Mebaral Dosage

Dosage form: tablet
Drug classes: Barbiturate anticonvulsants, Barbiturates

Medically reviewed by Last updated on May 15, 2024.


Average dose for adults: 400 mg to 600 mg (6 grains to 9 grains) daily; children under 5 years: 16 mg to 32 mg (1/4 grain to 1/2 grain) three or four times daily; children over 5 years: 32 mg to 64 mg (1/2 grain to 1 grain) three or four times daily. MEBARAL is best taken at bedtime if seizures generally occur at night, and during the day if attacks are diurnal.

Treatment should be started with a small dose which is gradually increased over four or five days until the optimum dosage is determined. If the patient has been taking some other antiepileptic drug, it should be tapered off as the doses of MEBARAL are increased, to guard against the temporary marked attacks that may occur when any treatment for epilepsy is changed abruptly. Similarly, when the dose is lowered to a maintenance level or to be discontinued, the amount should be reduced gradually over four or five days.

Special Patient Population

Dosage should be reduced in the elderly or debilitated because these patients may be more sensitive to barbiturates. Dosage should be reduced for patients with impaired renal function or hepatic disease.

Combination with Other Drugs

MEBARAL may be used in combination with phenobarbital, either in the form of alternating courses or concurrently. When the two drugs are used at the same time, the dose should be about one-half the amount of each used alone. The average daily dose for an adult is from 50 mg to 100 mg (3/4 grain to 1 1/2 grains) of phenobarbital and from 200 mg to 300 mg (3 grains to 4 1/2 grains) of MEBARAL.

MEBARAL may also be used with phenytoin sodium; in some cases, combined therapy appears to give better results than either agent used alone, since phenytoin sodium is particularly effective for the psychomotor types of seizure but relatively ineffective for petit mal. When the drugs are employed concurrently, a reduced dose of phenytoin sodium is advisable, but the full dose of MEBARAL may be given. Satisfactory results have been obtained with an average daily dose of 230 mg (3 1/2 grains) of phenytoin sodium plus about 600 mg (9 grains) of MEBARAL.


Adults: 32 mg to 100 mg (1/2 grain to 1 1/2 grains)-optimum dose, 50 mg (3/4 grain)-three to four times daily. Children: 16 mg to 32 mg (1/4 grain to 1/2 grain) three to four times daily.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.