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

September 9, 2026 updated by: safia bano

Comparison of Effectiveness of Benzhexol and Procyclidine in Improving Tremor in Tremor Predominant Parkinson's Disease Patients

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
88

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Pakistan
    • Punjab Province
      • Lahore, Punjab Province, Pakistan, 54000
        • Recruiting
        • Mayo Hospital Lahore
        • Sub-Investigator:
          • Ahsan Numan, FCPS,FAAN,FRCP,PhD
        • Contact:
        • Principal Investigator:
          • Saad A Malik, MBBS
        • Sub-Investigator:
          • Safia Bano, FCPS, PhD Scholar

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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:

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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
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.
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
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.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change from Baseline in Total Tremor Subset Score of the MDS-UPDRS Part III at 2 Weeks
Time Frame: From Baseline to Week 2
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.
From Baseline to Week 2

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Total Number of Side Effects
Time Frame: From Baseline to 6 months
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.
From Baseline to 6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
safia bano

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

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Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 3, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 3, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 9, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 14, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 9, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 751/RC/KEMU

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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