RESUMEN
Background: Dyspnea is frequently a debilitating symptom of chronic obstructive pulmonary disease (COPD). Cannabinoid receptor agonists have the potential to alter dyspnea in these patients. Objective: Our objective was to determine if dronabinol, a pure cannabinoid, improves dyspnea and exercise tolerance in COPD. Methods: In this double-blind randomized, crossover pilot study, COPD patients received up to 20mg of oral dronabinol or placebo daily for 6 weeks with an intervening washout period. Dyspnea and fatigue were assessed using the Borg scale at rest and after an incremental shuttle walk. Functional status, mood, and depression were measured using the St George's Respiratory Questionnaire (SGRQ), the Pulmonary Functional Status and Dyspnea Questionnaire (PFSDQ), and the Geriatric Depression Scale (GDS). Results: A total of 11 participants (with mean forced expiratory volume in 1 second 50.8 ± 24.8%) completed the study with no improvement in dyspnea at rest or postexercise taking dronabinol versus placebo (Borg scale 0.27, 95% confidence interval [CI] -0.59 to 1.14 versus 0.23 points, 95% CI -0.71 to 1.07 at rest and 0.82, 95% CI -0.59 to 2.22 versus 0.36 points, 95% CI 0.13 to 2.78 post exercise; p=0.94 and p=0.69 respectively). Dronabinol compared with placebo showed no significant change in PFSDQ dyspnea scores (0.64, 95% CI -3.92 to 5.20 versus 5.0, 95% CI -6.29 to 16.29; p=0.43) or shuttle walk distances (20.7m, 95% CI -21.5 to 62.8 versus 13.7m, 95% CI -24.8 to 52.2; p=0.69). There were no significant differences in fatigue at rest and postexercise, SGRQ scores, or GDS scores. Conclusion: In this pilot study, dronabinol did not significantly improve dyspnea or exercise capacity compared with placebo.
