$Unique_ID{BRK02105}
$Pretitle{}
$Title{PRIMIDONE}
$Subject{Myidone (Major)
Mysoline (Wyeth-Ayerst)
primidone (various manufacturers)}
$Volume{}
$Log{}

Copyright (C) 1991 Publications International, Ltd.


PRIMIDONE
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BRAND NAMES (Manufacturers):
     Myidone (Major)
     Mysoline (Wyeth-Ayerst)
     primidone (various manufacturers)
TYPE OF DRUG:
     Anticonvulsant
INGREDIENT:
     primidone
DOSAGE FORMS:
     Tablets (50 mg and 250 mg)
     Oral suspension (250 mg per 5-ml spoonful)
STORAGE:
     Primidone tablets and oral suspension should be stored at room
       temperature in tightly closed containers.  This medication should never
       be frozen.

USES

     Primidone is used to treat various seizure disorders.  This drug is
converted in the body to phenobarbital.  It is not clear exactly how primidone
or phenobarbital acts to decrease the number of seizures, but both drugs are
central nervous system (brain and spinal cord) depressants.

TREATMENT

     In order to avoid stomach irritation, you can take primidone with food or
with a full glass of water or milk (unless your doctor directs you to do
otherwise).
     The oral suspension form of this medication should be shaken well just
before measuring each dose.  The contents tend to settle on the bottom of the
bottle, so it is necessary to shake the container to distribute the
ingredients evenly and equalize the doses.  Each dose should then be measured
carefully with a specially designed 5-ml measuring spoon.  An ordinary kitchen
teaspoon is not accurate enough.
     Primidone works best when the level of medicine in your bloodstream is
kept constant.  It is best, therefore, to take the doses at evenly spaced
intervals day and night.  For example, if you are to take three doses a day,
the doses should be spaced eight hours apart.
     It is important to try not to miss any doses of this medication.  If you
do miss a dose and remember within two hours, take the missed dose
immediately.  If more than two hours has passed, do not take the missed dose
at all; just return to your regular dosing schedule.  Do not double the next
dose.  If you miss two or more consecutive doses, contact your doctor as soon
as possible.

SIDE EFFECTS

     Minor.

     Dizziness, drowsiness, fatigue, loss of appetite, nausea, or vomiting.
These side effects should disappear as your body adjusts to the medication.
     If you feel dizzy, sit or lie down for a while; get up slowly from a
sitting or reclining position, and be careful on stairs.

     Major.

     Tell your doctor about any side effects that are persistent or
particularly bothersome.  IT IS ESPECIALLY IMPORTANT TO TELL YOUR DOCTOR about
blurred vision, emotional disturbances, irritability, loss of coordination, or
skin rash.

INTERACTIONS

     Primidone interacts with several other types of medications:
     1. Concurrent use of primidone with other central nervous system
depressants (such as alcohol, antihistamines, barbiturates, benzodiazepine
tranquilizers, muscle relaxants, narcotics, pain medications, phenothiazine
tranquilizers, and sleeping medications) or with tricyclic antidepressants can
lead to extreme drowsiness.
     2. The blood levels and therapeutic effects of oral anticoagulants (blood
thinners, such as warfarin), adrenocorticosteroids (cortisone-like
medications), digitoxin, phenytoin, doxycycline, and tricyclic antidepressants
can be decreased by primidone.
     3. Primidone can decrease the absorption of griseofulvin from the
gastrointestinal tract, thereby decreasing its effectiveness.
     Before starting to take primidone, BE SURE TO TELL YOUR DOCTOR about any
medications you are currently taking, especially any of those listed above.

WARNINGS

     * Tell your doctor about unusual or allergic reactions you have had to
any medications, especially to primidone, phenobarbital, or other barbiturates
(such as amobarbital, butabarbital, mephobarbital, pentobarbital, and
secobarbital).
     * Before starting to take primidone, be sure to tell your doctor if you
now have or if you have ever had asthma, kidney disease, liver disease, or
porphyria.
     * If this drug makes you dizzy or drowsy, do not take part in any
activity that requires alertness, such as driving a car or operating
potentially dangerous machinery.
     * Before having surgery or any other medical or dental treatment, be sure
to tell your doctor or dentist that you are taking primidone.
     * Do not stop taking this medication unless you first check with your
doctor.  Stopping the drug abruptly can lead to a worsening of your condition.
Your doctor may, therefore, want to reduce your dosage gradually or start you
on another drug when primidone is stopped.
     * Be sure to tell your doctor if you are pregnant.  An increased risk of
birth defects in infants of mothers with seizure disorders has been reported.
It is unclear whether this increased risk is associated with the disorders or
with the anticonvulsant medications, such as primidone, that are used to treat
them.  Such drugs may also lead to bleeding complications in the newborn.  The
risks and benefits of treatment should be discussed with your doctor.  Also,
tell your doctor if you are breast-feeding an infant.  Primidone passes into
breast milk and can cause extreme drowsiness in nursing infants.

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The material contained here is "FOR INFORMATION ONLY" and should not replace 
the counsel and advice of your personal physician.  Promptly consulting your 
doctor is the best path to a quick and successful resolution of any medical 
problem.
