Brands, Medical Use, Clinical Data
Drug Category
- Antiparkinson Agents
- Antidyskinetics
Dosage Forms
Brands / Synonyms
Apo-Trihex; Artane; Artane Sequels; Benzhexol; Benzhexolum; Parkinane Retard; PMS Trihexyphenidyl; Tremin; Trihexane; Trihexifenidilo [Inn-Spanish]; Trihexy; Trihexylphenidyl; Trihexylphenidyle; Trihexylphenizyl; Trihexyphenidyl; Trihexyphenidyl HCl; Trihexyphenidyle; Trihexyphenidyle [Inn-French]; Trihexyphenidylum [Inn-Latin]; Triphenidyl
Indications
Indicated for the treatment of parkinson's disease and extrapyramidal reactions caused by drugs.
Pharmacology
Trihexyphenidyl is an anticholinergic used in the symptomatic treatment of all etiologic groups of parkinsonism and drug induced extrapyramidal reactions (except tardive dyskinesia). Trihexyphenidyl possesses both anticholinergic and antihistaminic effects, although only the former has been established as therapeutically significant in the management of parkinsonism.
Mechanism of Action
Trihexyphenidyl is a selective M1 muscarinic acetylcholine receptor antagonist. It is able to discriminate between the M1 (cortical or neuronal) and the peripheral muscarinic subtypes (cardiac and glandular). Trihexyphenidyl partially blocks cholinergic activity in the CNS, which is responsible for the symptoms of Parkinson's disease. It is also thought to increase the availability of dopamine, a brain chemical that is critical in the initiation and smooth control of voluntary muscle movement.
Absorption
Trihexyphenidyl is rapidly absorbed from the gastrointestinal tract.
Toxicity
Not Available
Biotrnasformation / Drug Metabolism
Not Available
Contraindications
ARTANE is contraindicated in patients with hypersensitivity to trihexyphenidyl HCl or to any of the tablet or
elixir ingredients. Artane is also contraindicated in patients with narrow angle glaucoma. Blindness after long-term
use due to narrow angle glaucoma has been reported.
Drug Interactions
Cannabinoids, barbiturates, opiates, and alcohol may have additive effects with Trihexyphenidyl, and thus, an abuse potential exists.
Concurrent use of alcohol or other CNS depressants with Trihexyphenidyl may cause increased sedative effects.
Monoamine oxidase inhibitors and tricyclic antidepressants possessing significant anticholinergic activity may intensify the anticholinergic effects of antidyskinetic agents because of the secondary anticholinergic activities of these medications.
Prophylactic administration of anticholinergic agents, such as trihexyphenidyl, as a prevention of drug-induced parkinsonism during neuroleptic therapy is not recommended. There may be an increased risk for the development of tardive dyskinesia during concomitant administration of anticholinergics and neuroleptics.
The usual dose of either trihexyphenidyl or levodopa may need to be reduced during concomitant therapy, since concomitant administration may increase drug-induced involuntary movements.
Nursing Mothers:
It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Trihexyphenidyl is administered to a nursing woman. As with other anticholinergics, trihexyphenidyl may cause suppression of lactation. Therefore, trihexyphenidyl should only be used if the expected benefit to the mother outweighs the potential risk to the infant.
Pediatric Use:
Safety and effectiveness in pediatric patients have not been established.
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