UnifiedACB

Medication evidence profile

Trihexyphenidyl

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Clinical overview

Anticholinergic antiparkinsonian agent

Trihexyphenidyl has public medication-list entries in JARS 2025, Yamada-ABS 2023, BAAS 2019, GABS 2018, KABS 2020 open validation supplement, and CALS 2022 Table 4. These are 6 separate source versions, each with its own evidence and definitions.

Source-specific scores

SourceScore
JARS3
Yamada-ABS3
BAAS3
Swe-ABSNot listed
GABS3
KABS3
CALS3

How to read this: 0 means the source explicitly assigned zero. “Not listed” means the source did not provide a score for this medication. Scores from different scales are not averaged.

Other names used in the sources

Trihexyphenidyl/benzhexol, benzhexol

How to interpret the evidence

6 of 7 public source versions contain an explicit medication-list entry for trihexyphenidyl.

The available rows for trihexyphenidyl display the same numeric value. Agreement of the displayed numbers does not establish identical methods, clinical meaning or patient-level risk.

None of the public rows in this profile is an explicit zero. An unlisted source still supplies no value.

Source labels and provenance · 6 observations
  1. Japanese Anticholinergic Risk Scale (JARS) 2025 English translation

    Source label: Trihexyphenidyl/benzhexol. Published value: 3.
    Source version: JARS-2025
    Source location: RC4 source recovery; recovery_scope=primary_table_complete; ATC=N04AA01
    Observation: JARS_2025_R0020; rating state: published_rating.

  2. Yamada Pharmacological Anticholinergic Burden Scale 2023

    Source label: Trihexyphenidyl. Published value: 3.
    Source version: YAMADA-ABS-2023
    Source location: RC4 source recovery; recovery_scope=primary_nonzero_complete
    Observation: YAMADA_ABS_2023_R0087; rating state: published_rating.

  3. Brazilian Anticholinergic Activity Scale 2019

    Source label: Trihexyphenidyl. Published value: 3.
    Source version: BAAS-2019
    Source location: RC4 source recovery; recovery_scope=primary_table_complete
    Observation: BAAS_2019_R0043; rating state: published_rating.

  4. German Anticholinergic Burden Score 2018

    Source label: Trihexyphenidyl. Published value: 3.
    Source version: GABS-2018
    Source location: RC4 source recovery; recovery_scope=primary_nonzero_complete
    Observation: GABS_2018_R0149; rating state: published_rating.

  5. KABS 2019 scale - 2020 open validation supplement

    Source label: Trihexyphenidyl. Published value: 3.
    Source version: KABS-2020-validation-supplement
    Source location: Additional file 1; category Anti-parkinson drugs; table row 35
    Observation: KABS2020_SUPP_0169; rating state: published_validation_supplement_rating.

  6. CALS 2022 - primary final Table 4

    Source label: Trihexyphenidyl. Published value: 3.
    Source version: CALS-2022-primary-table4
    Source location: Table 4; literal capture row 182; displayed table row 26; displayed column 7
    Observation: CALS2022_T4_0182; rating state: published_final_table_rating.

Class context — anticholinergic antiparkinsonian agents

These agents are identified as strongly anticholinergic. The 2023 general criterion also addresses their use in older adults. Route qualifications belong to the applicable medication and criterion.

AGS Beers 2023 Table 2; AGS Beers 2023 Table 7

Older-adult medication context

AGS Beers context: classification and criteria

AGS Beers 2023 · Strong anticholinergicBeers: Avoid / generally avoid in older adults
  • Table 7: Strong-anticholinergic reference listing.
  • Table 2: General older-adult medication criterion.

Source-scale observations and geriatric criteria answer different questions. The Beers material does not alter any score above.

Adults 65 years and older; intended for ambulatory, acute, and institutional care except hospice/end-of-life settings.

Condition-specific and medication-combination contexts

Table 3: clinical conditions

Condition-specific contexts: delirium or high delirium risk, dementia or cognitive impairment, and history of falls or fractures. Applicability depends on the condition and the relevant source criterion.

Table 5: cumulative anticholinergic exposure

Concurrent use of more than one anticholinergic medication should be minimized because cumulative exposure increases geriatric safety concerns.

American Geriatrics Society 2023 updated AGS Beers Criteria — Tables 2, 3, 5 and 7; selected criterion context.

Potentially inappropriate does not mean absolutely contraindicated. Apply the criterion in clinical context and use shared decision-making.

What this page does not establish

  • No medication-list entry is available here from Swe-ABS 2023. These gaps remain “Not listed”; no score is inferred from another source or from class membership.
  • No route inference unless present in the source label.
  • These source records do not estimate an individual’s probability of harm or establish whether to start, stop or change a medication. Ordinal source scores are not averaged into a UnifiedACB score.
Why is this medication clinically relevant to anticholinergic burden?Is this medication identified in the 2023 AGS Beers Criteria?What geriatric concerns are most relevant for this medication?

References

  1. Mizokami F, Mizuno T, Taguchi R, et al. Development of the Japanese Anticholinergic Risk Scale: English translation of the Japanese article. Geriatr Gerontol Int. 2025;25(1):5-13. doi:10.1111/ggi.15001. Open source
  2. Yamada S, Mochizuki M, Chimoto J, Futokoro R, Kagota S, Shinozuka K. Development of a pharmacological evidence-based anticholinergic burden scale for medications commonly used in older adults. Geriatr Gerontol Int. 2023;23(7):558-564. doi:10.1111/ggi.14619. Open source
  3. Nery RT, Reis AMM. Development of a Brazilian anticholinergic activity drug scale. Einstein (Sao Paulo). 2019;17(2):eAO4435. doi:10.31744/einstein_journal/2019AO4435. Open source
  4. Kiesel EK, Hopf YM, Drey M. An anticholinergic burden score for German prescribers: score development. BMC Geriatr. 2018;18(1):239. doi:10.1186/s12877-018-0929-6. Open source
  5. Suh Y, Ah YM, Han E, et al. Dose response relationship of cumulative anticholinergic exposure with incident dementia: validation study of Korean anticholinergic burden scale. BMC Geriatr. 2020;20(1):265. doi:10.1186/s12877-020-01671-z. Open source
  6. Ramos H, Moreno L, Pérez-Tur J, Cháfer-Pericás C, García-Lluch G, Pardo J. CRIDECO Anticholinergic Load Scale: an updated anticholinergic burden scale. Comparison with the ACB Scale in Spanish individuals with subjective memory complaints. J Pers Med. 2022;12(2):207. doi:10.3390/jpm12020207. Open source

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Medication context: Trihexyphenidyl

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