J Am Geriatr Soc. 2002 Oct; 50(10): 1751-2.

A traditional Chinese herbal medicine, banxia houpo tang, improves cough reflex of patients with aspiration pneumonia.

Iwasaki K, Cyong JC, Kitada S, Kitamura H, Ozeki J, Satoh Y, Suzuki T, Sasaki H.