Airway Responsiveness to Methacholine during the Natural Menstrual Cycle and the Effect of Oral Contraceptives1,2

Exacerbations of symptoms have been reported in some women with asthma just prior to and during menstruation. We examined changes in airway responsiveness to methacholine during 2 consecutive menstrual cycles in 17 well-controlled asthmatics with a wide range of airway responsiveness. In 10 women with regular natural cycles, measurements were made 1 wk before and 1 wk after the start of menstruation to coincide with the highest and lowest …