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RecruitingNCT07810296Updated Sep 14, 2026

Comparison of Benzhexol and Procyclidine for Tremor in Tremor-Predominant Parkinson's Disease

An interventional study of Benzhexol and Procyclidine in Parkinson Disease (PD), sponsored by safia bano. Recruiting at 1 site in Pakistan. Open to participants aged 40 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-09-14.

Sponsored by safia bano · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
88
Allocation
Randomized
Ages
40 Years to 70 Years
Sex
All
01

Study summary

The goal of this clinical trial is to compare benzhexol and procyclidine for improving tremor in adults with tremor-predominant Parkinson's disease who are taking levodopa. Researchers will compare the two medicines to determine whether benzhexol provides similar improvement in tremor to procyclidine and to assess their side effects. Participants will be randomly assigned to receive either benzhexol or procyclidine in addition to their usual levodopa treatment. Motor symptoms and side effects will be assessed before treatment and at 2 weeks, 3 months, and 6 months.

Read the detailed description

This randomized clinical trial will compare the effectiveness of benzhexol and procyclidine in improving tremor in patients with tremor-predominant Parkinson's disease who are receiving levodopa therapy.

Eligible participants will be adults aged 40 to 70 years with clinically diagnosed Parkinson's disease, predominant tremor at presentation, Hoehn and Yahr stage 1, 2, or 3, and resting tremor while receiving levodopa/carbidopa monotherapy. Participants with cognitive or behavioral abnormalities, lower urinary tract symptoms, benign prostatic hyperplasia, angle-closure glaucoma, or cardiac disease will be excluded.

Participants will be randomly assigned to one of two treatment groups. Group A will receive benzhexol and Group B will receive procyclidine, in addition to their existing levodopa treatment. Benzhexol will be started at 2 mg on the first day, increased to 2 mg twice daily on day 4 and to 2 mg three times daily on day 7, with subsequent dose adjustment according to tremor response and tolerability. Procyclidine will be started at 2.5 mg three times daily on day 1, increased according to the protocol to a maximum of 5 mg three times daily by day 7, with subsequent dose adjustment according to tremor response and tolerability.

Motor symptoms will be assessed using Part III of the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS-III). The primary assessment will focus on the total tremor subset score comprising the following eight items: postural tremor of the right hand, postural tremor of the left hand, rest tremor amplitude of the right upper extremity, rest tremor amplitude of the left upper extremity, rest tremor amplitude of the right lower extremity, rest tremor amplitude of the left lower extremity, rest tremor amplitude of the lip/jaw, and constancy of rest tremor.

Improvement will be assessed as the absolute change in the total tremor subset score from baseline, with the primary comparison made at the 2-week follow-up. The study aims to determine whether benzhexol provides at least similar improvement in tremor compared with procyclidine.

Participants will be assessed at baseline and at 2 weeks, 3 months, and 6 months after treatment initiation. MDS-UPDRS-III assessments will be performed by an independent observer, and adverse effects and tolerability of the study medications will be assessed and documented at follow-up visits.

The planned study enrollment is 88 participants, with 44 participants allocated to each treatment group. The study will be conducted in the Department of Neurology, Mayo Hospital, Lahore.

02

Conditions studied

  • Parkinson Disease (PD)

Keywords

  • Tremor
  • Tremor-Predominant Parkinson Disease
  • Benzhexol
  • Procyclidine
  • Anticholinergic
03

Who can participate

Ages eligible
40 Years to 70 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Diagnosed Parkinson's disease according to the Movement Disorder Society Clinical Diagnostic Criteria for Parkinson's Disease, with predominant tremor at presentation.
  • Hoehn and Yahr stage 1, 2, or 3.
  • Any gender.
  • Age 40 to 70 years.
  • Receiving levodopa/carbidopa monotherapy for Parkinson's disease, with resting tremor present.

Exclusion criteria

Exclusion Criteria:

  • Cognitive or behavioral abnormalities.
  • Lower urinary tract symptoms.
  • Benign prostatic hyperplasia.
  • Angle-closure glaucoma.
  • Cardiac disease.
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Care provider)
Enrollment
88 participants (estimated)

Study arms

  • Experimental
    Benzhexol

    Participants will receive benzhexol in addition to levodopa/carbidopa therapy. Benzhexol will be started at 2 mg on day 1, increased to 2 mg twice daily on day 4 and to 2 mg three times daily on day 7. The dose will subsequently be adjusted according to resolution of tremor or development of side effects. If tremor resolves, benzhexol will be continued at the effective dose; if intolerable side effects develop, the dose will be reduced and subsequently stopped if side effects persist. Participants will be followed for 6 months with assessments at baseline, 2 weeks, 3 months, and 6 months.

    Drug: Benzhexol

  • Active comparator
    Procyclidine

    Participants will receive procyclidine in addition to levodopa/carbidopa therapy. Procyclidine will be started at 2.5 mg three times daily on day 1, increased to 5 mg in the morning plus 2.5 mg in the afternoon and evening on day 3, then to 5 mg in the morning and afternoon with 2.5 mg in the evening on day 5, and finally up to 5 mg three times daily on day 7. The dose will subsequently be adjusted according to resolution of tremor or development of side effects. If tremor resolves, procyclidine will be continued at the effective dose; if intolerable side effects develop, the dose will be reduced and subsequently stopped if side effects persist. Participants will be followed for 6 months with assessments at baseline, 2 weeks, 3 months, and 6 months.

    Drug: Procyclidine

Interventions

  • DrugBenzhexol

    Benzhexol will be administered orally. Treatment will start at 2 mg on day 1, increase to 2 mg twice daily on day 4, and increase to 2 mg three times daily on day 7. The dose will subsequently be adjusted according to tremor response and tolerability. Treatment will continue for up to 6 months unless stopped because of persistent intolerable side effects.

  • DrugProcyclidine

    Procyclidine will be administered orally. Treatment will start at 2.5 mg three times daily on day 1, increase to 5 mg in the morning plus 2.5 mg in the afternoon and evening on day 3, then to 5 mg in the morning and afternoon with 2.5 mg in the evening on day 5, and finally up to 5 mg three times daily on day 7. The dose will subsequently be adjusted according to tremor response and tolerability. Treatment will continue for up to 6 months unless stopped because of persistent intolerable side effects.

05

What researchers measure

Primary outcomes

  1. Change from Baseline in Total Tremor Subset Score of the MDS-UPDRS Part III at 2 Weeks

    The total tremor subset score is the sum of Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III tremor items: postural tremor of the right hand, postural tremor of the left hand, kinetic tremor of right hand, kinetic tremor of left hand, rest tremor amplitude of the right upper extremity, rest tremor amplitude of the left upper extremity, rest tremor amplitude of the right lower extremity, rest tremor amplitude of the left lower extremity, rest tremor amplitude of the lip/jaw, and constancy of rest tremor. The minimum score is 0 and maximum score is 40 for tremor subset scores with a lower score indicating better function. Change from baseline will be calculated as the baseline total score minus the total score at 2 weeks, with a greater positive change representing greater improvement in tremor.

    Time frame: From Baseline to Week 2

Secondary outcomes

  1. Total Number of Side Effects

    The total number of side effects reported or observed in participants in the benzhexol and procyclidine groups during the study will be recorded and compared between the two treatment groups. Side effects will be assessed and documented during follow-up visits.

    Time frame: From Baseline to 6 months

06

Study locations

1 of 1 sites recruiting
  • Mayo Hospital Lahore
    Lahore, Punjab Province 54000, Pakistan
    • Saad A Malik, MBBS · Contact · saadazhar@live.com · +92-3005107713
    • Saad A Malik, MBBS · Principal investigator
    • Safia Bano, FCPS, PhD Scholar · Sub investigator
    • Ahsan Numan, FCPS,FAAN,FRCP,PhD · Sub investigator
    Recruiting
07

References and documents

Publications

  • Habib, Md. Ahsan & Alamgir, ASM & Dey, Subash Kanti & Alam, Afroja & Asafuddoula, Ahmed & Rizvi, Abu. (2016). Effect of Trihexiphenidyl and Procyclidine for the management of resting tremor. Bangladesh Medical Journal. 44. 72-75. 10.3329/bmj.v44i2.27241.
  • Goetz CG, Tilley BC, Shaftman SR, Stebbins GT, Fahn S, Martinez-Martin P, Poewe W, Sampaio C, Stern MB, Dodel R, Dubois B, Holloway R, Jankovic J, Kulisevsky J, Lang AE, Lees A, Leurgans S, LeWitt PA, Nyenhuis D, Olanow CW, Rascol O, Schrag A, Teresi JA, van Hilten JJ, LaPelle N; Movement Disorder Society UPDRS Revision Task Force. Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS): scale presentation and clinimetric testing results. Mov Disord. 2008 Nov 15;23(15):2129-70. doi: 10.1002/mds.22340. PubMed 19025984 ↗
  • Sahoo LK, Holla VV, Batra D, Prasad S, Bhattacharya A, Kamble N, Yadav R, Pal PK. Comparison of effectiveness of trihexyphenidyl and levodopa on motor symptoms in Parkinson's disease. J Neural Transm (Vienna). 2020 Dec;127(12):1599-1606. doi: 10.1007/s00702-020-02257-0. Epub 2020 Oct 9. PubMed 33037478 ↗
  • Barrett MJ, Sargent L, Nawaz H, Weintraub D, Price ET, Willis AW. Antimuscarinic Anticholinergic Medications in Parkinson Disease: To Prescribe or Deprescribe? Mov Disord Clin Pract. 2021 Oct 8;8(8):1181-1188. doi: 10.1002/mdc3.13347. eCollection 2021 Nov. PubMed 34765683 ↗
  • Lees A, Tolosa E, Stocchi F, Ferreira JJ, Rascol O, Antonini A, Poewe W. Optimizing levodopa therapy, when and how? Perspectives on the importance of delivery and the potential for an early combination approach. Expert Rev Neurother. 2023 Jan;23(1):15-24. doi: 10.1080/14737175.2023.2176220. Epub 2023 Feb 10. PubMed 36729395 ↗
  • Vazquez-Velez GE, Zoghbi HY. Parkinson's Disease Genetics and Pathophysiology. Annu Rev Neurosci. 2021 Jul 8;44:87-108. doi: 10.1146/annurev-neuro-100720-034518. PubMed 34236893 ↗
  • Peng S, Liu P, Wang X, Li K. Global, regional and national burden of Parkinson's disease in people over 55 years of age: a systematic analysis of the global burden of disease study, 1991-2021. BMC Neurol. 2025 Apr 23;25(1):178. doi: 10.1186/s12883-025-04191-8. PubMed 40269818 ↗
  • Ou Z, Pan J, Tang S, Duan D, Yu D, Nong H, Wang Z. Global Trends in the Incidence, Prevalence, and Years Lived With Disability of Parkinson's Disease in 204 Countries/Territories From 1990 to 2019. Front Public Health. 2021 Dec 7;9:776847. doi: 10.3389/fpubh.2021.776847. eCollection 2021. PubMed 34950630 ↗
08

Registry details

Key details

Study ID
NCT07810296
Lead sponsor
safia bano
Responsible party
safia bano (Assistant Professor Neurology, King Edward Medical University) — Sponsor-investigator
First posted
Sep 9, 2026
Start date
Sep 2026 (estimated)
Primary completion
Jul 2027 (estimated)
Completion
Jul 2027 (estimated)
Last update
Sep 14, 2026

Study contacts

Saad A Malik, MBBS
Contact
saadazhar@live.com
+92-3005107713

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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