title: Positron emission tomography evaluation of sedative properties of antihistamines.
abstract: BACKGROUND
  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.
  
  
  METHODS
  This article reviews the current updated literature on the sedative properties of antihistamines examined by PET measurement of H(1) receptor occupancy.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Tohoku University Graduate School of Medicine, Department of Pharmacology, Sendai, Japan. yanai@med.tohoku.ac.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yanai
authors.forename: Dongying
authors.initials: D
authors.lastname: Zhang
authors.forename: Manabu
authors.initials: M
authors.lastname: Tashiro
authors.forename: Takeo
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Fumito
authors.initials: F
authors.lastname: Naganuma
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Harada
authors.forename: Tadaho
authors.initials: T
authors.lastname: Nakamura
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Shibuya
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Okamura
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism*; D006633:Histamine Antagonists / Q000378:metabolism / Q000494:pharmacology*; D006634:Histamine H1 Antagonists / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000378:metabolism / Q000494:pharmacology*; D049268:Positron-Emission Tomography / Q000379:methods; D011969:Receptors, Histamine H1 / Q000378:metabolism
chemical_list: D006633:Histamine Antagonists; D006634:Histamine H1 Antagonists; D006993:Hypnotics and Sedatives; D011969:Receptors, Histamine H1