Research

Phosphodiesterase 3 inhibition and cough in elderly asthmatics

Yoshihisa Ishiura¹ , Masaki Fujimura² , Kouichi Nobata² , Miki Abo¹ , Takayoshi Oribe¹ , Shigeharu Myou² and Hiroyuki Nakamura¹

¹  The Department of Internal Medicine, Toyama City Hospital, Toyama, Japan

²  Respiratory Medicine, Cellular Transplantation Biology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan

author email corresponding author email

Cough 2005, 1:11doi:10.1186/1745-9974-1-11

Published:	24 November 2005

Abstract

Aims

Cough is a common symptom of bronchial asthma, a chronic inflammatory airway disease. Recently, the therapeutic effects of selective phosphodiesterase (PDE) inhibitors have been focused on bronchial asthma. This study was designed to investigate the clinical effect of PDE 3 inhibition on cough reflex sensitivity in elderly patients with bronchial asthma.

Methods

Effects of cilostazol, a PDE 3 inhibitor, on cough response to inhaled capsaicin were examined in 11 patients over 70 years with stable asthma in a randomized, placebo-controlled cross over study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough reflex sensitivity.

Results

The cough threshold was significantly (p < 0.05) increased after two-week treatment with cilostazol (100 mg twice a day orally) compared with placebo [48.8 (GSEM 1.4) vs. 29.2 (GSEM 1.3) μM].

Conclusion

These findings indicate that PDE 3 inhibition may be a novel therapeutic option for elderly patients with asthma, especially for their cough symptoms.