Prostanoids and the Cough Reflex

Prostanoids such as prostaglandin (PG) D₂, PGE₂, PGF_2α, prostacyclin (PGI₂), and thromboxane (Tx) A₂ act via five classes of receptors named DP, EP, FP, IP, and TP, respectively, and mediate a diverse range of physiological effects. Prostanoids are commonly associated with many diseases as a proinflammatory mediator; however, in the lung, prostanoids, particularly PGE₂, seem to have a protective role. Inhaled PGE₂ has been shown to be anti-inflammatory and a bronchodilator but causes cough. This has hindered the development of prostanoids for the treatment of airway inflammatory diseases. We discuss here the extensive research into the role of prostanoids in the airways and their modulation of the cough reflex.