Pediatric Movement Disorders - Treatments

Trihexyphenidyl (Artane®)

Trihexyphenidyl is probably the most effective medication to treat dystonia of unknown cause. It is an anticholinergic medicine, meaning that it acts to block acetylcholine receptors in the brain. Its action is similar to that of diphenhydramine (Benadryl®) and other over-the-counter cold/allergy medicines. Trihexyphenidyl's effect on the brain seems to be more specific. Side effects include dry mouth, blurred vision, constipation, urinary retention, and rapid heart rate. These side effects are usually much less frequent in children than adults; therefore children tolerate much higher doses; in some cases, the dose may be as high as 100 mg per day, or even higher. Extremely high doses are often required to see a benefit and it can take a long time to increase the dose to this level. If side effects are bothersome, the blurred vision may be controlled with pilocarpine eye drops; urinary retention can be controlled with bethanechol.