Pharmacokinetics and pharmacodynamics of a short- and long-acting theophylline medication (Theolair and Theolair retard) in normals and patients with COLD. Part III: Plasma cyclic AMP.

Supporting evidence was found for the beta-blockade theory of Szentivanyi. Asthmatics (n = 6) showed lower basal plasma cyclic AMP levels and lower cyclic AMP levels after administration of a short- and long-acting theophylline preparations (Theolair and Theolair retard) than normals (n = 6) did. No difference was found in this respect between Theolair and Theolair retard. Basal cyclic AMP levels showed a diurnal variation, with highest levels in the morning which gradually decreased during the day. The correlation of the plasma cyclic AMP levels with the lung function change after stimulation with theophyllines in asthmatics was rather poor. This is probably caused by the rather low changes in plasma cyclic AMP levels.