Aims: There is no evidence demonstrating the clinical usefulness of phosphodiesterase (PDE) inhibitors in the treatment of asthma, although PDE3 and 4 inhibitors have received much attention for the treatment of bronchial asthma. We compared the bronchodilator effects of intravenously administered olprinone, a selective PDE3 inhibitor, and aminophylline, a nonselective PDE inhibitor, both alone and concomitantly.
Methods: In 12 patients with mild stable asthma, we compared the acute bronchodilator effects of the following two drugs, alone and together using a double-blind crossover design: intravenous administration of olprinone, 30 micro g min-1; aminophylline, 2.25 mg min-1; and olprinone plus aminophylline over a total period of 150 min.
Results: Mean maximal increase (95% confidence interval) in the FEV1 was 7.8% (2.4, 13.2), 17.1% (10.0, 24.2), 16.6% (11.2, 22.0), and 1.0% (-1.1, 3.1) during infusion of aminophylline, olprinone, aminophylline and olprinone, and saline, respectively. The magnitude of bronchodilatation produced by olprinone was greater than that by aminophylline. The combination of aminophylline and olprinone did not produce any greater bronchodilatation than olprinone alone. Olprinone alone or in combination with aminophylline lowered diastolic blood pressure, and increased heart rate.
Conclusions: These results suggest that the intravenous administration of PDE3 inhibitors exhibits a bronchodilatory effect. There are no additive or synergistic effects of administration of olprinone and aminophylline at the same time.