$Unique_ID{BRK02174}
$Pretitle{}
$Title{TRIHEXYPHENIDYL}
$Subject{Artane (Lederle)
Artane Sequels (Lederle)
Trihexane (Rugby)
Trihexidyl (Henry Schein)
Trihexy (Geneva Generics)
trihexyphenidyl hydrochloride (various manufacturers)}
$Volume{}
$Log{}

Copyright (C) 1991 Publications International, Ltd.


TRIHEXYPHENIDYL
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BRAND NAMES (Manufacturers):
     Artane (Lederle)
     Artane Sequels (Lederle)
     Trihexane (Rugby)
     Trihexidyl (Henry Schein)
     Trihexy (Geneva Generics)
     trihexyphenidyl hydrochloride (various manufacturers)
TYPE OF DRUG:
     Antiparkinsonism agent
INGREDIENT:
     trihexyphenidyl
DOSAGE FORMS:
     Tablets (2 mg and 5 mg)
     Sustained-release capsules (5 mg)
     Oral elixir (2 mg per 5-ml spoonful, with 5% alcohol)
STORAGE:
     Store at room temperature in a tightly closed container.  This medication
       should never be frozen.

USES

     Trihexyphenidyl is used to treat the symptoms of Parkinson's disease or
to control the side effects of phenothiazine tranquilizers.  It is not clearly
understood how this medication works, but it is thought to act by balancing
certain chemicals in the brain.

TREATMENT

     In order to reduce stomach irritation, you should take trihexyphenidyl
with food or just after a meal.
     Antacids and antidiarrheal medications prevent the absorption of this
medication from the gastrointestinal tract, so at least one hour should
separate doses of trihexyphenidyl and one of these medicines.
     The oral elixir form of this medication should be measured carefully with
a specially designed 5-ml measuring spoon.  An ordinary kitchen teaspoon is
not accurate enough.
     The sustained-release capsules should be swallowed whole.  Chewing,
crushing, or breaking the capsules destroys their sustained-release activity
and possibly increases the side effects.
     If you miss a dose of this medication, take the missed dose as soon as
possible, unless it is within two hours of the next dose of the tablets or
oral elixir or within eight hours of the next dose of the sustained-release
capsules.  In that case, do not take the missed dose at all; just return to
your regular dosing schedule.  Do not double the next dose.

SIDE EFFECTS

     Minor.

     Bloating; blurred vision; constipation; decreased sweating; dizziness;
drowsiness; dry mouth, throat, and nose; false sense of well-being; headache;
increased sensitivity of the eyes to light; muscle cramps; nausea;
nervousness; and weakness.  These side effects should disappear as your body
adjusts to the medication.
     If you are constipated, increase the amount of fiber in your diet (fresh
fruits and vegetables, salads, bran, whole-grain breads), exercise, and drink
more water (unless your doctor directs you to do otherwise).
     Chew sugarless gum or suck on ice chips or a piece of hard candy to
reduce mouth dryness.
     Wear sunglasses if you find that your eyes have become sensitive to
light.
     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
confusion, depression, difficulty in urinating, hallucinations, involuntary
muscle movements, numbness or tingling of the fingers or toes, palpitations,
or unusual excitement.

INTERACTIONS

     Trihexyphenidyl interacts with other types of medications:
     1. It can cause extreme drowsiness when combined with alcohol or other
central nervous system depressants (drugs that slow the activity of the brain
and spinal cord), such as antihistamines, barbiturates, benzodiazepine
tranquilizers, muscle relaxants, narcotics, and pain medications, or with
tricyclic antidepressants.
     2. Amantadine, antihistamines, haloperidol, monoamine oxidase (MAO)
inhibitors, phenothiazine tranquilizers, procainamide, quinidine, and
tricyclic antidepressants can increase the side effects of trihexyphenidyl.
At least 14 days should separate the use of this drug and the use of an MAO
inhibitor.
     3. Trihexyphenidyl can increase the elimination of chlorpromazine from
the body and thus decrease its effectiveness.
     4. Trihexyphenidyl can decrease the effectiveness of the drug levodopa.
     BE SURE TO TELL YOUR DOCTOR about any medications you are currently
taking, especially any of the medications that are listed above.

WARNINGS

     * Tell your doctor about unusual or allergic reactions you have had to
any medications, especially to trihexyphenidyl.
     * Tell your doctor if you now have or if you have ever had achalasia,
glaucoma, heart disease, myasthenia gravis, blockage of the intestinal or
urinary tract, enlarged prostate gland, stomach ulcers, or thyroid disease.
     * If this drug makes you dizzy or drowsy, avoid any activity that
requires alertness, such as driving a car or operating potentially dangerous
machinery.  Be careful on stairs, and avoid standing up suddenly.
     * This medication can decrease sweating and heat release from the body.
You should, therefore, try not to get overheated (avoid exercising strenuously
in hot weather, and do not take hot baths, showers, or saunas).
     * Your doctor may recommend periodic eye exams to check pressure in your
eyes.
     * Be sure to tell your doctor if you are pregnant.  Although
trihexyphenidyl appears to be safe during pregnancy, extensive studies have
not been conducted.  Also, tell your doctor if you are breast-feeding an
infant.  Small amounts of this medication may pass into breast milk.

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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.
