after joining the study, you attend an enrollment visit where study staff confirm eligibility and obtain written consent.

the visit includes collection of basic health information and review of current medications.

a series of assessments are performed to document the starting condition.

these include a physical examination, laboratory tests, and questionnaires such as the mds-updrs, moCA, and pdq-8 to evaluate motor function, cognition, and quality of life.

you begin taking montelukast 60 mg by mouth once each day.

montelukast is the active substance; the dose is expressed in milligrams, which is a standard unit of weight for medicines.

the medication is taken continuously for the entire extension period of the trial.

you return to the study site at scheduled intervals, typically every three months.

during each visit, safety labs are drawn, and the same questionnaires used at baseline are repeated to track changes.

any new symptoms or side effects are recorded.

outside of scheduled visits, you are asked to report any adverse event (unwanted medical occurrence) as soon as it is noticed.

the study team may contact you to obtain additional information if needed.

at the end of the trial period, you attend a final visit that repeats the baseline assessments.

the purpose is to evaluate long‑term safety, tolerability, and any changes in disease measures.