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trademark for preparations of primidone, an anticonvulsant.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


Apo-Primidone (CA), Mysoline

Pharmacologic class: Barbiturate

Therapeutic class: Anticonvulsant

Pregnancy risk category NR


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


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


• Hypersensitivity to drug or phenobarbital

• Porphyria


Use cautiously in:

• hepatic, renal, or chronic obstructive pulmonary disease

• pregnant or breastfeeding patients

• hyperactive children.


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

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,


Skin: flushing, rash


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

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

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.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


A brand name for the ANTICONVULSANT drug primidone, used in the control of EPILEPSY.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
Mysoline is a prescription drug for the treatment of certain types of epilepsy, essential tremors and seizures.
Since AstraZeneca decided to stop making Mysoline national pressure group Epilepsy Action has been fighting to keep it available.
The first-generation AEDs known to cause birth defects and other developmental toxicities include the hydantoins (ethotoin [Peganone], fosphenytoin [Cerebyx], mephenvtoin [Mesantoin], and phenytoin [Dilantin]), phenobarbital, primidone (Mysoline), carbamazepine (Tegretol), and valproic acid derivatives (Depakene, Depakote).
And some of these drugs--particularly phenytoin, primidone (Mysoline), and phenobarbital--inhibit the transfer of vitamin K across the placenta.
At that time he was having at least 10 seizures a day and was taking lamotragine (Lamictal), mysoline (Primidone), and clonazepam (Klonopin).
Dilantin, phenobarbital, Tegretol, Depakene/Depakote, Mysoline, Zarontin, Klonopin
ET isn't curable, but blood pressure medications known as beta blockers--usually propranolol (Inderal)--or an anti-seizure medication such as primidone (Mysoline) may be prescribed alone or together to control bothersome tremors.
(food records, food frequency or typical intake interview) Table 2 Medication-Nutrient interactions associated with medications frequently prescribed for children with special healthcare needs Medications Use Drug Nutrient Interaction Carbamazepine (Tegretol), Anticonvulsants Decreased folic phentoin (Dilantin), acid levels with phenybarbital, primidone concurrent increased (Mysoline) Valproic Acid homocysteine levels.
He said he was now walking and talking normally after firing the doctor who prescribed him copious amounts of valium, dexederine, mysoline and other drugs.