The efficacy and safety of duloxetine in treating refractory chronic cough: a randomized clinical trial.

BACKGROUND

Enhanced cough sensitivity is proposed as a potential cause for refractory chronic cough (RCC), and modulation of sensory nerve hyperresponsiveness is suggested as an effective treatment. However, the treatment of RCC has considerable potential for enhancement, particularly in terms of the targets and side effects. We aimed to investigate the efficacy and safety of duloxetine, a selective 5-HT and norepinephrine reuptake inhibitor, in patients with RCC.

METHODS

This is a prospective, randomized, double-blind trial. RCC patients without mood disorders in the Tongji Hospital of Tongji University outpatient clinic were invited to participate in this study. Patients were randomly assigned to the duloxetine group or placebo group, with both patients and investigators being masked. The co-primary endpoint was the change in Leicester cough questionnaire (LCQ) score and cough frequency.

RESULTS

Between Oct 2020 and May 2024, 98 patients were randomly assigned to duloxetine (n = 49) and placebo (n = 49) groups. After an 8-week treatment phase and a 3-week follow-up period, the mean number of coughs per hour in the duloxetine group was reduced from 83.96 ± 28.95 to 33.12 ± 22.99, showing a significant decrease than that of the placebo group (87.67 ± 31.75 to 80.36 ± 31.75) (p < 0.001). In addition, duloxetine significantly improved scores on the LCQ (12.75 ± 2.44 to 14.88 ± 2.45), whereas no significant reduction was observed in the placebo group (12.17 ± 2.64 to 12.81 ± 2.32) (P < 0.001 between groups). However, adverse events such as nausea 5 (11.36%), dizziness 7 (15.91%), and somnolence 4 (9.09%) occurred more frequently in the duloxetine group (all P < 0.05).

CONCLUSIONS

Duloxetine reduced cough frequency and sensitivity, which appears to be a novel therapeutic approach for RCC.

TRIAL REGISTRATION: The study was approved by the Ethics Committee of Shanghai Tongji Hospital (2020-KYSB-160, 2021-086) and registered in the Chinese Clinical Trial Registry (ChiCTR2000037429).