What Is Trihexyphenidyl Used For?
Trihexyphenidyl for Extrapyramidal Symptoms
Extrapyramidal symptoms (also known as EPS) are a set of side effects that are common with antipsychotic medications, as well as a few other types of medications. Extrapyramidal symptoms are usually divided into different categories. Dyskinesias are movement disorders, while dystonias are muscle tension disorders. "Tardive" symptoms are those that appear during long-term treatment (often after several years of treatment). Unlike earlier symptoms, tardive symptoms are more likely to be permanent, even after the medication is stopped.
Trihexyphenidyl can be very effective for controlling most EPS. However, trihexyphenidyl should not be used to treat tardive dyskinesia, as it is not effective for this use and may even worsen tardive dyskinesia.
How Does Trihexyphenidyl Work?
Trihexyphenidyl is an anticholinergic medication. It works by blocking the effects of acetylcholine (a neurotransmitter), a chemical in the nervous system. Normal muscle movement control requires a careful balance of acetylcholine and dopamine (another neurotransmitter). In Parkinson's disease (and with extrapyramidal disorders caused by antipsychotic medications), dopamine levels are decreased, creating an imbalance between dopamine and acetylcholine. By blocking the effects of acetylcholine, trihexyphenidyl helps to re-establish a normal balance between dopamine and acetylcholine.
Trihexyphenidyl also has antihistamine effects, but these effects are not thought to be important for treating Parkinson's disease or extrapyramidal symptoms.
Trihexyphenidyl Uses in Children
Trihexyphenidyl is not specifically approved for use in children. Discuss the potential risks and benefits of the drug with your child's healthcare provider.
Off-Label Trihexyphenidyl Uses
On occasion, your healthcare provider may recommend trihexyphenidyl for something other than the conditions discussed in this article. At this time, using trihexyphenidyl to treat excessive salivation ("drooling") due to medications or other causes is considered an off-label trihexyphenidyl use.