primidone

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primidone

[pri´mĭ-dōn] an anticonvulsant used in the treatment of epilepsy; administered orally.

primidone

Apo-Primidone (CA), Mysoline

Pharmacologic class: Barbiturate

Therapeutic class: Anticonvulsant

Pregnancy risk category NR

Action

Unknown. May raise seizure threshold by decreasing neuronal firing after being converted to phenobarbital.

Availability

Suspension: 250 mg/5 ml

Tablets: 50 mg, 250 mg

Indications and dosages

➣ Grand mal, psychomotor, or focal epileptic seizures

Adults and children ages 8 and older: Initially, 100 to 125 mg P.O. at bedtime on days 1 to 3, then 100 to 125 mg P.O. b.i.d. on days 4 to 6, then 100 to 125 mg P.O. t.i.d. on days 7 to 9, followed by a maintenance dosage of 250 mg P.O. three or four times daily

Children younger than age 8: Initially, 50 mg P.O. at bedtime on days 1 to 3, then 50 mg P.O. b.i.d. on days 4 to 6, then 100 mg P.O. b.i.d. on days 7 to 9. For maintenance, 125 to 250 mg t.i.d. or 10 to 25 mg/kg/day in divided doses.

Dosage adjustment

• Renal impairment

Off-label uses

• Benign familial (essential) tremor

Contraindications

• Hypersensitivity to drug or phenobarbital

• Porphyria

Precautions

Use cautiously in:

• hepatic, renal, or chronic obstructive pulmonary disease

• pregnant or breastfeeding patients

• hyperactive children.

Administration

• Don't change brands. Bioequivalency problems have occurred.

See Don't stop therapy suddenly. Dosage must be tapered.

• Know that drug may be given alone or with other anticonvulsants.

Adverse reactions

CNS: headache, dizziness, stimulation, drowsiness, sedation, confusion, hallucinations, psychosis, ataxia, vertigo, hyperirritability, emotional disturbances, paranoid symptoms, coma

EENT: diplopia, nystagmus, eyelid edema

GI: nausea, vomiting, anorexia

GU: erectile dysfunction

Hematologic: megaloblastic anemia,

thrombocytopenia

Skin: flushing, rash

Interactions

Drug-drug. Acetazolamide, succinimide: decreased primidone blood level Carbamazepine: decreased primidone blood level, increased carbamazepine blood level

Hydantoins, isoniazid, nicotinamide: increased primidone blood level

Drug-diagnostic tests. Hemoglobin, platelets: decreased levels

Liver function tests: altered results

Patient monitoring

• Monitor primidone and phenobarbital blood levels.

• Monitor CBC and blood chemistry. Watch for evidence of blood dyscrasias.

• Assess neurologic status regularly. Stay alert for excessive drowsiness and emotional status changes.

Patient teaching

See Caution patient not to discontinue therapy suddenly. Advise him to discuss dosage changes with prescriber.

See Instruct patient to immediately report unusual bleeding, bruising, or rash.

• Tell patient drug may cause sexual dysfunction. Advise him to discuss this issue with prescriber.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, vision, and alertness.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.

primidone

Desoxyphenobarbital Neurology An anticonvulsant used as a monotherapy for partial seizures–eg, secondary generalized seizures. See Phenobarbital, Seizures.

primidone

An ANTICONVULSANT drug used in the treatment of EPILEPSY. A brand name is Mysoline.

primidone

primidone

primidone

primidone

Action

Availability

Indications and dosages

Dosage adjustment

Off-label uses

Contraindications

Precautions

Administration

Adverse reactions

Interactions

Patient monitoring

Patient teaching

primidone

primidone

primidone

Synonyms for primidone

noun an anticonvulsant (trade name Mysoline) used to treat grand mal seizures and essential tremor

Synonyms

Related Words