Effects of prostacyclin on aspecifically and specifically induced bronchoconstriction in asthmatic patients.

: The efficacy of prostacyclin in preventing aspecifically and specifically induced bronchoconstriction was evaluated in a single-blind cross-over study in 3 groups of asthmatic patients. Prostacyclin was given by inhalation in doses of 250 microgram in women and 500 microgram in men. Ultrasonic mist of H2O (group 1), physical exercise on cycloergometer (group 2) and pneumoallergens (group 3) were used as bronchial stimulant agents. Prostacyclin gave a very good protection in the first 2 groups, but was ineffective in the third. An increase in heart rate was observed immediately after the inhalation of prostacyclin: this effect was particularly evident in women in whom a significant decrease in diastolic pressure was noted too.