Investigating the effect of Montelukast drug on pulmonary function and clinical symptoms of patients with moderate to severe COPD

Comparison of the mean difference in FEV1 Comparison of the mean difference in FVC Comparison of the mean difference in FEF25–75% Comparison of the mean difference in FEV₁/FVC ratio Comparison of the number of exacerbation episodes Comparison of clinical improvement in dyspnea based on the modified MMRC questionnaire Comparison of clinical improvement in dyspnea based on the COPD Assessment Test (CAT)

Randomized triple-blind phase 2 clinical trial, parallel-group design, including one intervention group (Montelukast 10 mg daily for two months) and one placebo group (one tablet daily for two months). Sixty-two patients will be randomized using balanced block randomization (using online software).

This study will be conducted at Imam Khomeini Hospital in Ahvaz and in related pulmonary specialists’ offices. Blinding is maintained for all study stakeholders, including the patient, prescriber, outcome assessor, data analyst, investigator, and oversight committee members, due to the use of placebo. The data analyst will perform analyses based on two anonymized groups labeled A and B.

Inclusion criteria: Patients aged 40 to 70 years diagnosed with moderate to severe COPD, clinically stable over the past three months, with no history of hospitalization in the past six months, and who have completed a written informed consent form. Exclusion criteria: Patients with advanced cardiovascular disease; autoimmune or inflammatory rheumatologic disorders; uncontrolled hypertension; progressive kidney disease; and hypersensitivity to Montelukast.

Intervention: Montelukast (Zahravi Pharmaceutical Company) one 10 mg tablet daily for two months. Control: A placebo daily for two months. Jundishapur Faculty of Pharmacy manufactures the placebo.

Forced expiratory volume, Forced vital capacity

Randomization method and description: Balanced block randomization. Unit of randomization: Individual participant. Stratification layers (if stratified randomization is used): Not applicable. Randomization tool: The sequence of drug and placebo allocation is determined using statistical software and predefined block sizes. Random sequence generation: Drug and placebo packages are identical in appearance and labeled with sequential numbers according to the randomization list. These are provided to the designated unit/person responsible for dispensing the intervention, to be distributed in order to participants enrolled in the study. Allocation concealment: The randomization list is prepared in duplicate and kept by an individual not involved in the study and not present at the study site. During data analysis, only two groups labeled A and B are provided to the analyst. The identity of the drug and placebo groups is revealed only after completion of the analysis and summary of results.

Since the placebo in this study is manufactured and provided by the producing company, there is no visual difference between what is given to the dispenser and the patient. Therefore, there is no way for the outcome assessor, data analyst, or even members of the safety and data monitoring committee to identify the type of intervention. All parties remain blinded to whether the patient receives the active drug or the placebo.