Efficacy and safety of glycopyrrolate/formoterol fumarate metered dose inhaler in patients with tuberculosis-associated chronic obstructive pulmonary disease: study protocol for a randomised controlled trial

Background Clinical trials have shown that glycopyrrolate/formoterol fumarate improves lung function in patients with chronic obstructive pulmonary disease (COPD) caused by tobacco exposure. Although tuberculosis-associated COPD has worse respiratory health outcomes than smoking-associated COPD, no clinical trials have determined whether pharmacological intervention is effective. We designed a clinical trial to evaluate the safety and efficacy of glycopyrrolate/formoterol fumarate for the treatment of tuberculosis-associated COPD. Methods We report the protocol for a prospective, multicentre, open-label, parallel-group, observer-blind, randomised clinical trial in China. Tuberculosis-associated COPD will be defined as a history of pulmonary tuberculosis and imaging manifestations, no current long-term anti-tuberculosis treatment, smoking index 1 )/forced vital capacity (FVC) ratio 1 ≥50% predicted. Patients with tuberculosis-associated COPD will be randomly assigned (1:1) to the glycopyrrolate/formoterol fumarate metered dose inhaler (18 µg/9.6 µg twice daily) or no additional treatment. All patients will be provided with salbutamol as rescue medication. The primary outcome will be the between-group difference in the change from baseline to 12 weeks in prebronchodilator FEV 1 . The key secondary outcomes will be the between-group difference in the change from baseline to 12 weeks in postbronchodilator FEV 1 ; percentage predicted prebronchodilator and postbronchodilator FEV 1 , FVC, and percentage predicted FVC; and COPD Assessment Test scores. Discussion The results of the PTB-COPD trial will provide the first insights into the pharmacological treatment of tuberculosis-associated COPD. We anticipate the results of this trial to be available in the first half of 2027. Trial registration Chinese Clinical Trial Registry, ChiCTR2500103088. Registered on May 23, 2025.