User:Mr. Ibrahem/Trihexyphenidyl

Trihexyphenidyl (THP), also known as benzhexol, is a medication used to treat Parkinsonism and certain extrapyramidal symptoms that occur as a result of antipsychotic medication. Use is not recommended in Parkinson’s disease due to side effects. It is taken by mouth. Onset of effects are within an hour and can last up to 12 hours.

Common side effects include dry mouth, blurry vision, nausea, and dizziness. Other side effects may include misuse, anxiety, trouble sleeping, and hallucinations. It is in the antimuscarinic class and works by reducing cholinergic activity in the brain.

Trihexyphenidyl was patented in 1948 and came into medical use in 1949. It is on the World Health Organization's List of Essential Medicines as an alternative to biperiden. It is available as a generic medication. In the United Kingdom 84 tablets of 2 mg cost the NHS less than 5 pounds as of 2021. In the United States it is similarly inexpensive.