UsesTrihexyphenidyl is used to treat symptoms of Parkinson’s disease (a type of nerve disease that causes movement disorder characterized by slowness of movements, muscle stiffness, uncontrolled shaking and poor balance and co-ordination) and drug-induced extra pyramidal symptoms (movement disorders similar to symptoms of Parkinson’s disease) except tardive dyskinesia (involuntary movement of face and jaw). It is often given along with levodopa (anti-Parkinson drug)
Mechanism of ActionTrihexyphenidyl is an anticholinergic agent, which works by blocking the action of a chemical called acetylcholine on the nerves which results in relaxing of smooth muscles; thereby, reducing the rigidity of muscle spasm (sudden involuntary contraction of a muscle or group of muscles), tremor (uncontrolled shaking) and excessive salivation associated with Parkinson’s disease
DosageAdult- PO- Initial: The recommended dose is 1 mg/day in 3-4 divided doses, increased gradually up to 6-10 mg/day according to response
Side EffectsAnxiety Tachycardia Restlessness Blurring of vision Hallucination Impaired memory Euphoria Difficulty urinating and rash Dryness of mouth
Warnings/PrecautionsTrihexyphenidyl is not recommended for use in patients with tardive dyskinesia (involuntary movement of face and jaw) and in children under 18 years of age Trihexyphenidyl is not recommended as prophylaxis (preventive treatment) for drug-induced parkinsonism. Avoid abrupt discontinuation of treatment as it can result in worsening of symptoms of Parkinson’s disease or emergence of life-threatening complications (neuroleptic malignant syndrome) Take precautions while driving or operating machinery as trihexyphenidyl can impair mental and physical abilities Use trihexyphenidyl with caution in hot weather as it can increase susceptibility to heat stroke (symptoms: very high fever, inability to bear heat, nausea, vomiting etc.) Please consult your doctor if you are pregnant or planning to become pregnant or are breastfeeding