ERS 2024: Inhaled alkaline hypertonic divalent salts reduce refractory chronic cough frequency.
Summary
A single-blinded study in 12 chronic cough patients evaluated the cough-suppression efficacy of nasally delivered SC001 (pH 8 or 9) versus saline. Using Hyfe CoughMonitor, patients were monitored over three weeks. Results suggest alkaline (pH 9) SC001 aerosol shows promise for refractory chronic cough treatment.
Background: The hydration status of surface liquid in the larynx and trachea may regulate peripheral cough receptors.
Hypothesis: Topical hypertonic divalent salts (HDS) buffered to alkalinity provides relief for refractory chronic cough.
Methods: We conducted an exploratory, single-blinded controlled study in 12 chronic cough patients to examine cough-suppression efficacy of a nasally delivered HDS composition (SC001) at pH 8 or pH 9, compared to a normal saline (NS) control. Subjects were monitored continuously using the Hyfe CoughMonitor smartwatch for one week of baseline, one week of NS, and one week of SC001.
Results: Baseline cough rates ranged from 4 to 41 coughs/hr with a mean visual analog score (VAS) of 65±17. Adjusting for control, SC001 demonstrated efficacy at suppressing cough by 15% from Day 1 (p=0.015) and 23% from Day 3 (p=0.002) overall (n=12). Efficacy was highest in subjects treated with SC001 pH 9 (n=5), with a 25% cough-suppression observed from Day 1 (p=0.03) and 35% from Day 3 (p=0.02). Lower efficacy was observed for SC001 pH 8 (n=7), with 9% (p=0.08) and 16% (p=0.02) suppression observed from Day 1 and Day 3 respectively. Hourly cough counts correlated with VAS scores (ρ = 0.266, p-value = 0.015) at baseline and increased with treatment (ρ = 0.507, p-value = 0.000002). No adverse events were reported.
Conclusions: Alkaline (pH 9) HDS aerosol is a promising treatment for refractory chronic cough.
