The acute and chronic bronchodilator effects of ephedrine in asthmatic patients.

In eight asthmatic patients, there was no change in the bronchodilator response to a single dose of ephedrine (22 mg) given alone or in a compound tablet, after treatment with ephedrine (11 mg three times a day) or one tablet three times a day for 2 weeks. 2 There was no deterioration in lung function during the 2 week treatment period with either ephedrine or the compound tablet. 3 An inter-patient variation was noted in the plasma ephedrine concentraition required for bronchodilatation. 4 The half-life of theophylline did not change after chronic treatment with the tablets, one three times a day for 2 weeks.