-benztropine
-drugs for bladder problems
-drugs for breathing problems like ipratropium and tiotropium
-drugs for certain stomach or intestine problems like propantheline, homatropine methylbromide, glycopyrrolate, atropine, belladonna, and dicyclomine
-levodopa
-scopolamine

They need to know if you have any of these conditions:
-glaucoma
-heart disease
-high blood pressure
-kidney disease
-liver disease
-prostate problems
-an unusual or allergic reaction to trihexyphenidyl, other medicines, lactose, foods, dyes, or preservatives
-pregnant or trying to get pregnant
-breast-feeding

Your doctor or health care professional may want you to have eye exams while you are taking this medicine.

Your mouth may get dry. Chewing sugarless gum or sucking hard candy, and drinking plenty of water may help. Contact your doctor if the problem does not go away or is severe.

This medicine may cause dry eyes and blurred vision. If you wear contact lenses you may feel some discomfort. Lubricating drops may help. See your eye doctor if the problem does not go away or is severe.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.

Keep out of the reach of children.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Throw away any unused medicine after the expiration date.