Preoperative Withdrawal of Propranolol

To the Editor.— The clinical review "Noncardiac Surgery in Patients With Coronary Artery Disease: Risks, Precautions, and Perioperative Management" by Hillis and Cohn, which appeared in theArchives(138:972-975, 1978), placed many problems relating to this topic in perspective. However, the authors' approach to the preoperative management of the patient taking propranolol hydrochloride is presented as though withdrawal of the drug in the manner described was a well-accepted principle. One finds that the literature no longer supports the need for preoperative withdrawal of propranolol as an anesthetic hazard. Original concerns about the myocardial depressant effects of certain anesthetic agents being potentiated by β-blockade are no longer present. For example, Slogoff et al,1in the dog model, demonstrated that propranolol added to but did not potentiate the effects of morphine and halothane. To evaluate the safety of propranolol plus other agents, Kopriva et al,2in a prospective study, measured