TY - JOUR
T1 - Efficacy and tolerability of zinc acetate for treatment of chronic refractory cough
T2 - pilot randomised futility trial
AU - Balasubramanian, Aparna
AU - Holbrook, Janet T.
AU - Canning, Brendan J.
AU - Que, Loretta G.
AU - Castro, Mario
AU - Make, Barry J.
AU - Rogers, Linda
AU - Busk, Michael F.
AU - Rea, Alexis
AU - McCook-Veal, Ashley A.
AU - He, Jiaxian
AU - McCormack, Meredith C.
AU - Wise, Robert A.
N1 - Funding Information:
Support statement: This research was funded by grants from the American Lung Association and the National Institutes of Health – National Heart, Lung, and Blood Institute 1R34HL132369-01 National Heart, Lung, and Blood Institute. Funding information for this article has been deposited with the Crossref Funder Registry.
Publisher Copyright:
© The authors 2023.
PY - 2023
Y1 - 2023
N2 - Background: Cough is the most reported symptom in the United States, with chronic refractory cough representing significant morbidity to patients. Zinc acetate may have beneficial effects in the cough reflex pathway. We sought to assess the safety and efficacy of zinc acetate in the management of chronic refractory cough. Study design and methods: This was a randomised, placebo-controlled, parallel-design pilot trial of individuals with chronic refractory cough. The effects of 6 weeks of zinc acetate versus placebo on quality of life and symptoms as measured by the Cough Quality-of-Life Questionnaire (CQLQ), Leicester Cough Questionnaire (LCQ), cough visual analogue score (C-VAS) and Global Assessment of Change in Cough (GACC) scores were evaluated. A futility analysis plan with a one-sided 80% confidence interval was used to compare treatment effect to published minimum clinically important differences (MCID) for each outcome. Results: 34 participants, 17 in each group, were enrolled and randomised. Participants were primarily white females with moderate–severe cough. Participants assigned to zinc acetate had a significant increase in serum zinc levels after 6 weeks, while those assigned to placebo did not. Both groups showed improvement in CQLQ, LCQ, C-VAS and GACC scores, but the treatment effects of zinc acetate versus placebo were small with confidence intervals that did not include the MCIDs. Interpretation: We observed no benefit of zinc therapy over placebo on cough symptoms or quality of life and conclude that larger trials of zinc for chronic cough are not warranted.
AB - Background: Cough is the most reported symptom in the United States, with chronic refractory cough representing significant morbidity to patients. Zinc acetate may have beneficial effects in the cough reflex pathway. We sought to assess the safety and efficacy of zinc acetate in the management of chronic refractory cough. Study design and methods: This was a randomised, placebo-controlled, parallel-design pilot trial of individuals with chronic refractory cough. The effects of 6 weeks of zinc acetate versus placebo on quality of life and symptoms as measured by the Cough Quality-of-Life Questionnaire (CQLQ), Leicester Cough Questionnaire (LCQ), cough visual analogue score (C-VAS) and Global Assessment of Change in Cough (GACC) scores were evaluated. A futility analysis plan with a one-sided 80% confidence interval was used to compare treatment effect to published minimum clinically important differences (MCID) for each outcome. Results: 34 participants, 17 in each group, were enrolled and randomised. Participants were primarily white females with moderate–severe cough. Participants assigned to zinc acetate had a significant increase in serum zinc levels after 6 weeks, while those assigned to placebo did not. Both groups showed improvement in CQLQ, LCQ, C-VAS and GACC scores, but the treatment effects of zinc acetate versus placebo were small with confidence intervals that did not include the MCIDs. Interpretation: We observed no benefit of zinc therapy over placebo on cough symptoms or quality of life and conclude that larger trials of zinc for chronic cough are not warranted.
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U2 - 10.1183/23120541.00678-2022
DO - 10.1183/23120541.00678-2022
M3 - Article
C2 - 37057088
AN - SCOPUS:85159128696
SN - 2312-0541
VL - 9
JO - ERJ Open Research
JF - ERJ Open Research
IS - 2
M1 - 00678-2022
ER -