THE EFFECTS OF ORAL-ADMINISTRATION OF (-)-MENTHOL ON NASAL RESISTANCE TO AIR-FLOW AND NASAL SENSATION OF AIR-FLOW IN SUBJECTS SUFFERING FROM NASAL CONGESTION ASSOCIATED WITH THE COMMON COLD

Abstract— The effects of oral administration of a lozenge containing 11 mg (—)‐menthol on nasal resistance to airflow (NAR) and nasal sensation of airflow in 62 subjects suffering from nasal congestion associated with naturally acquired common cold infection have been studied. NAR was measured by posterior rhinomanometry and nasal sensation of airflow by means of a visual analogue scale (VAS). The effects of the lozenge were compared with a candy placebo lozenge in a double blind randomized trial. NAR showed a significant increase (P < 0.05) in both the menthol and placebo groups over the 2 h experiment with no difference between the groups at any time. The VAS scores showed significant changes of subjective improvement in nasal sensation of airflow (P < 0.001) in the menthol‐treated group 10 min after dosing whereas the placebo group showed no change. It is concluded that dosing with 11 mg menthol in subjects with common cold has no effect on NAR as measured by posterior rhinomanometry but causes a marked change in nasal sensation of airflow with a subjective sensation of nasal decongestion. 1990 Royal Pharmaceutical Society of Great Britain