Methods: In a double-blinded, placebo-controlled study, 30 NAR patients randomized to Dymista (n=20) or Placebo (n=10) treatment groups were initially (Pre-Rx visit) exposed to CDA (~14°C, ×1hr.) and again two-weeks post treatment (Post-Rx visit); NLFs were collected pre- and post-CDA exposure at each visit. Enzyme immunoassays were used to measure SP levels in NLF. Association of CDA-induced cough-counts with log-normalized SP ratio (post/pre-exposure) was determined by correlational and linear regression analysis.
Results: Log(SP)-ratio differed significantly between Dymista-Post-Rx vs. Dymista-Pre-Rx samples (est.= -0.739, p=0.00004) and Dymista-Post-Rx vs. Placebo-Post-Rx (est.=-0.748, p=0.00051). Within the Dymista-group CDA-induced cough-counts post-Rx visit were significantly decreased (p=0.0003) and correlated with a reduction in the Log(SP)-ratio (Spearman rho=0.33, p=0.03).
Conclusions: Dymista may have a significant clinical effect in NAR by reduction in SP secretion. Larger clinical studies are warranted to demonstrate the clinical effect of Dymista in the NAR treatment.