PRIMIDONE

Brand & Generic Names

Apo-Primidone
Myidone
Mysoline
PMS Primadone
Sertan

Basic Information

• Habit forming? No
• Prescription needed? Yes
• Available as generic? Yes
• Drug class: Anticonvulsant

Uses

Prevents some forms of epileptic seizures.

Dosage & Usage Information

How to take:
Tablet--Swallow with liquid. If you can't swallow whole, crumble tablet and take with liquid or food.
Liquid--If desired, dilute dose in beverage before swallowing.

When to take:
Daily in regularly spaced doses, according to doctor's prescription.

If you forget a dose:
Take as soon as you remember up to 2 hours late. If more than 2 hours, wait for next scheduled dose (don't double this dose).

What drug does:
Probably inhibits repetitious spread of impulses along nerve pathways.

Time lapse before drug works:
2 to 3 weeks.

Don't take with:
Any other medicine without consulting your doctor or pharmacist.

Overdose

SYMPTOMS:
Slow, shallow breathing; weak, rapid pulse; confusion, deep sleep, coma.

WHAT TO DO:

• Dial 911 (emergency) or O (operator) for an ambulance or medical help. Then give first aid immediately.
• If patient is unconscious and not breathing, give mouth-to- mouth breathing. If there is no heartbeat, use cardiac massage and mouth-to-mouth breathing (CPR). Don't try to make patient vomit. If you can't get help quickly, take patient to nearest emergency facility.
• See EMERGENCY Information.

Possible Adverse Reactions or Side Effects

Life-threatening:

In case of overdose, see Overdose section.

Common:

• Difficult breathing.
• Confusion, change in vision.
• Clumsiness, dizziness, drowsiness.

Infrequent:

• Unusual excitement, particularly in children; nausea; vomiting.
• Headache, fatigue, weakness.

Rare:

• Rash or hives, appetite loss, acute psychosis, hair loss, fever, joint pain.
• Swollen eyelids or legs.
• Decreased sexual ability.

Warnings & Precautions

Don't take if:

• You are allergic to any barbiturate.
• You have had porphyria.

Before you start, consult your doctor:

• If you have had liver, kidney or lung disease or asthma.
• If you have lupus.

Over age 60:
Adverse reactions and side effects may be more frequent and severe than in younger persons.

Pregnancy:
Studies inconclusive on harm to unborn child. Animal studies show fetal abnormalities. Decide with your doctor whether drug benefits justify risk to unborn child.

Breast-feeding:
Drug filters into milk. May harm child. Avoid. Consult doctor.

Infants & children:
Use only under medical supervision.

Prolonged use:

• Enlarged lymph and thyroid glands.
• Anemia.
• Rickets in children and osteomalacia (insufficient calcium to bones) in adults.
• Talk to your doctor about the need for follow-up medical examinations or laboratory studies to check complete blood counts (white blood cell count, platelet count, red blood cell count, hemoglobin, hematocrit), liver function, kidney function.

Skin & sunlight:
None expected.

Driving, piloting or hazardous work:
Don't drive or pilot aircraft until you learn how medicine affects you. Don't work around dangerous machinery. Don't climb ladders or work in high places. Danger increases if you drink alcohol or take medicine affecting alertness and reflexes.

Discontinuing:
Don't discontinue abruptly or without doctor's advice until you complete prescribed dose, even though symptoms diminish or disappear.

Others:

• Tell doctor if you become ill or injured and must interrupt dose schedule.
• Periodic laboratory blood tests of drug level recommended.

Possible Interaction with Other Drugs

GENERIC NAME	COMBINED EFFECT
------------------------	-----------------------
Anticoagulants*,	Decreased primidone effect.
Anticonvulsants*,	Changed seizure pattern.
Antidepressants*	Increased antidepressant effect.
Antidiabetics*	Increased sedation effect of
	primidone.
Antihistamines*	Increased sedation effect of
	primidone.
Aspirin	Decreased aspirin effect.
Carbamazepine	Unpredictable increase or decrease
	of primidone effect.
Carbonic anhydrase	Possible decreased primidone effect.
Central nervous system	Increased CNS depressant effects.
Contraceptives*,	Decreased contraceptive effect.
Cortisone drugs*	Decreased cortisone effect.
Cyclosporine	Decreased effect of cyclosporine.
Digitalis	Decreased digitalis effect.
Disulfiram	Possible increased primidone
	effect.
Estrogens*	Decreased estrogen effect.
Griseofulvin	Possible decreased griseofulvin
	effect.
Isoniazid	Decreased primidone effect.
Leucovorin	May counteract anticonvulsant
(large dose)	effect of primidone.
Loxapine	Decreased anticonvulsant effect of
	primidone.
MAO inhibitors*	Increased sedation effect of
	primidone.
Metronidazole	Possible decreased metronidazole
	effect.
Mind-altering drugs*	Increased effect of mind-altering
	drugs.
Nabilone	Greater depression of central
	nervous system.
Narcotics*	Increased narcotic effect.
Oxyphenbutazone	Decreased oxyphenbutazone effect.
Phenylbutazone	Decreased phenylbutazone effect.
Phenytoin	Possible increased primidone
	toxicity.
Rifampin	Possible decreased primidone
	effect.
Sedatives*	Increased sedative effect.
Sertraline	Increased depressive effects
	of both drugs.
Sleep inducers*	Increased effect of sleep inducer.
Tranquilizers*	Increased tranquilizer effect.

Possible Interaction with Other Substances

INTERACTS WITH	COMBINED EFFECT
---------------	---------------
Alcohol:	Dangerous sedative effect. Avoid.
Beverages:	None expected.
Cocaine:	Decreased primidone effect.
Foods:	Possible need for more vitamin D.
Marijuana:	Decreased anticonvulsant effect of
	primidone. Drowsiness,
	unsteadiness.
Tobacco:	None expected.