Diphenhydramine Enhances the Interaction of Hypercapnic and Hypoxic Ventilatory Drive

Abstract

We conclude that although it did not affect the ventilatory response to carbon dioxide during hyperoxia or the ventilatory response to hypoxia at an end-tidal carbon dioxide tension of 46 mmHg diphenhydramine augmented the hypoxic response under conditions of hypercapnia in our young healthy volunteers. Although these findings may help to explain the apparent safety of diphenhydramine, they may not be applicable to debilitated patients or those who have received systemic or neuraxial ventilatory depressants.