Product Information

Registration Status: Active

APO-TRIHEX TABLET 2mg is approved to be sold in Singapore with effective from 1991-05-21. It is marketed by PHARMAFORTE SINGAPORE PTE LTD, with the registration number of SIN05827P.

This product contains Trihexyphenidyl 2mg in the form of TABLET. It is approved for ORAL use.

This product is manufactured by APOTEX INC in CANADA.

It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.



One of the centrally acting muscarinic antagonists used for treatment of parkinsonian disorders and drug-induced extrapyramidal movement disorders and as an antispasmodic. [PubChem]


Indicated for the treatment of parkinson's disease and extrapyramidal reactions caused by drugs.

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.


Trihexyphenidyl is rapidly absorbed from the gastrointestinal tract.


Symptoms of overdose include mydriasis, dryness of mucous membranes, red face, atonic states of bowels and bladder, and hyperthermia in high doses. Central consequences are agitation, confusion, and hallucinations. An untreated overdose may be fatal, particular in children. Premortal signs are respiratory depression and cardiac arrest.

Active Ingredient/Synonyms

(RS)-1-cyclohexyl-1-phenyl-3-(1-piperidyl)propan-1-ol | Apo-trihex | Benzhexol Hydrochloride | Trihexifenidilo | Trihexyphenidyl | Trihexyphénidyle | Trihexyphenidylum | Trihexyphenidyl |

Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


  1. Health Science Authority of Singapore - Reclassified POM
  2. Drugbank