Efficacy and predictors of response to inhaled corticosteroid treatment for chronic cough

Abstract

Background/aims: Inhaled corticosteroids (ICS) are a treatment of choice for eosinophilic airway diseases, but their efficacy for other causes of chronic cough is controversial.

Methods: We conducted a prospective observational study to determine the ICS efficacy and clinical predictors of response to ICS in patients with upper airway cough syndrome (UACS) or unexplained chronic cough (UCC). Sixty-eight patients with UACS and 33 patients with UCC (duration of cough ≥ 8 weeks) were treated with ICS: 250 µg of fluticasone propionate or 400 µg of budesonide twice a day at physician's discretion. They were followed after 2 weeks to assess persistent cough which was measured as 0% to 100% compared with baseline cough frequency.

Results: The median grade of persistent cough after 2-week ICS treatment was 40% (interquartile range [IQR], 10 to 70) in UACS and was 50% (IQR, 20 to 70) in UCC. The only adverse event was infrequent, mild hoarse voice (five UACS and one UCC). Long duration of cough (≥ 52 weeks) and cough not aggravated by cold air exposure were predictors of a poorer response to short course ICS treatment (logistic regression analysis, p = 0.018 and p = 0.031, respectively). However, prolonged treatment with ICS more than 2 weeks was more effective in patients with long cough duration (≥ 52 weeks).

Conclusion: Short course ICS treatment has modest efficacy on UACS and UCC without significant adverse events. Duration of cough and cough triggered by cold air exposure were the clinical factors associated with ICS response. Extended treatment with ICS may be beneficial in patients with long duration of cough.

Keywords: Adrenal cortex hormones; Cough; Treatment outcome.

Figure 1.

The proportion of study participants according to the degree of persistent cough after 2-week treatment with inhaled corticosteroid. A good response to 2-week inhaled corticosteroid treatment was defined as having a persistent cough after treatment that was ≤ 50% of baseline cough frequency level (100%) after treatment. UACS, upper airway cough syndrome; UCC, unexplained chronic cough.

Figure 2.

Median degree of persistent cough after 2-week treatment with inhaled corticosteroid varied according to duration of cough reported at baseline (p = 0.004, linear trend test).

Figure 3.

The decrease of persistent cough (% relative to baseline) after prolonged treatment with inhaled corticosteroid. (A) Patients with cough duration < 52 weeks (n = 28). (B) Patients with cough duration ≥ 52 weeks (n = 14). In patients with cough duration longer than 52 weeks, prolonged treatment with ICS for more than 2 weeks was followed by a significantly lower degree of persistent cough (median persistent cough [Q1 to Q3], T1: 50% [30 to 80], T2: 0% [0 to 35], p <0.05). T0, baseline; T1, 2 weeks after T0; T2, more than 2 weeks after T1. ^ap < 0.05 analyzed by Friedman test with Dunn’s post-test.