Menthol: effects on nasal sensation of airflow and the drive to breathe.

Menthol, in lozenges, nasal sprays, vapo-rubs, inhalers, and cough syrups, is widely used as a treatment for rhinitis that is associated with acute upper respiratory tract infection and allergy. Menthol as a plant extract has been used in traditional medicine in Asia for the treatment of respiratory diseases for hundreds of years, but it was only introduced to the West as a medicine at the end of the 19th century. With the recent discovery of a menthol receptor on the sensory nerves that modulate the cool sensation, menthol has graduated from the realms of herbal medicine into the field of molecular pharmacology. This review concerns the physiologic and pharmacologic mechanisms that underlie the widespread use of menthol as a treatment for the relief of nasal congestion associated with rhinitis and its effects on the drive to breathe and symptomatic relief of dyspnea.