Trihexyphenidyl
Artane
Synthetic Anticholinergic AgentGeneric available
Trihexyphenidyl exerts direct inhibitory effect on parasympathetic nervous system and relaxing effect on smooth musculature (directly on muscle tissue and indirectly via parasympathetic inhibition). Similar to atropine but with fewer/less severe undesirable side effects. Blocks cholinergic activity centrally and peripherally. Therapeutic benefit in parkinsonism and drug-induced EPS via central anticholinergic effects.
Compare Trihexyphenidyl →FDA-Approved Indications
- All forms of parkinsonism (postencephalitic, arteriosclerotic, idiopathic) — as adjunct
- Extrapyramidal disorders from CNS drugs (antipsychotics, phenothiazines)
- Adjuvant therapy with levodopa for Parkinson disease
Common Off-Label Uses
- Generalized dystonia (younger patients tolerate well)
- Sialorrhea/drooling from clozapine
What Sets This Drug Apart
- Anticholinergic for drug-induced EPS and parkinsonism — preferred alternative to benztropine for some patients
- CRITICAL: Narrow-angle glaucoma contraindication with risk of blindness — gonioscope evaluation mandatory before therapy
- Severe anhidrosis and potentially fatal hyperthermia in hot weather — dose reduction required if sweating decreases
- Neuroleptic malignant syndrome reported with dose reduction/discontinuation — potentially fatal syndrome
- Cognitive dysfunction (confusion, memory impairment, forgetfulness) especially in elderly — contraindicated per Beers Criteria
- Abuse potential: euphoria and psychiatric disturbances can result from indiscriminate use to sustain continued euphoria