Positron emission tomography evaluation of sedative properties of antihistamines

Abstract

Introduction: H(1) antihistamines are often used in the medication for allergic diseases, coughs and colds, and insomnia, with or without prescription, even though their sedative properties are a potentially dangerous unwanted side effect that is not properly recognized. These sedative properties have been evaluated using the incidence of subjective sleepiness, objective cognitive and psychomotor functions, and positron emission tomography (PET) measurement of H(1) receptor occupancy.

Areas covered: This article reviews the current updated literature on the sedative properties of antihistamines examined by PET measurement of H(1) receptor occupancy.

Expert opinion: The use of PET to examine antihistamine penetration in the human brain in relation to psychometric and other functional measures of CNS effects is a major breakthrough and provides a new standard by which the functional CNS effects of antihistamines can be related directly to H(1) receptor occupancy. Therapy with antihistamines can be better guided by considering histamine H(1) receptor occupancy from the view of their sedative properties.