Effects of beta-adrenergic and calcium antagonists on the development of anaphylactoid reactions from radiographic contrast media during cardiac angiography.

Anaphylactoid reactions (ARs) occurring in patients receiving propranolol have been described as unusually severe and having a "sluggish" response to epinephrine. Although the mechanism of ARs to iodinated radiographic contrast media is not IgE mediated, because of widespread use of beta-adrenergic blocking agents, we undertook a prospective study to determine the incidence of AR to radiographic contrast media during cardiac angiography. Nine hundred fifty-two consecutive patients were divided into four groups according to concomitant chronic medications. Group I (447 patients) were receiving no beta-adrenergic blocking agents or calcium antagonists. Group II (216 patients) were receiving a beta-adrenergic blocking agent. Group III (147 patients) were receiving a calcium antagonist but not a beta-adrenergic blocking agent. Group IV (142 patients) were receiving both a calcium antagonist and a beta-adrenergic blocking agent. The reaction rates, respectively, in the four groups were 4.47%, 7.41%, 5.44%, and 4.93%. The rates of ARs were not associated with the use of concomitant medications in any of the groups (chi 2 = 2.531; p = 0.47). The probability of a type II error in comparison of groups I and II was 0.75 should the true incidence of reactions in patients receiving beta-adrenergic antagonists be 7.41%. No difference in the incidence of AR was observed between patients taking selective and nonselective beta-adrenergic blocking agents in group II. Specific ARs occurring in patients receiving beta-adrenergic blocking agents were usually mild and often without need for specific pharmacotherapy.