Functional neuroimaging of cognition impaired by a classical antihistamine, d‐chlorpheniramine
Open Access
- 30 January 2000
- journal article
- clinical trial
- Published by Wiley in British Journal of Pharmacology
- Vol. 129 (1), 115-123
- https://doi.org/10.1038/sj.bjp.0702994
Abstract
Antihistamine induced cognitive decline was evaluated using positron emission tomography (PET) measurement of histamine H1 receptor (H1R) occupancy and regional cerebral blood flow (rCBF). Cognitive performance in attention‐demanding task deteriorated dose‐dependently and the effects were statistically significant after the treatment of 2 mg of d‐chlorpheniramine. There was no significant change in subjective sleepiness in the same dose. The regional blockade of H1R was observed mainly in the frontal, temporal and anterior cingulate cortices, and the intravenous administration of d‐chlorpheniramine as a therapeutic dose (2 mg) blocked over 60% of H1R in the frontal cortices. The results from activation study using visual discrimination tasks demonstrated that enhanced activity in the right prefrontal and anterior cingulate cortices as well as a decreased activity in the left temporal and frontal cortices and midbrain after the treatment of d‐chlorpheniramine. There were no changes in global CBF for the subjects treated with 2 mg d‐chlorpheniramine (pre; 44.8±3.3 ml dl−1 min−1 vs post; 44.4±4.7 ml dl−1 min−1). The results indicated that the attention system of human brain could be altered by therapeutic doses of H1R antagonists. These findings provide the information as to the potential risk of antihistamines in our daily activities. British Journal of Pharmacology (2000) 129, 115–123; doi:10.1038/sj.bjp.0702994Keywords
This publication has 48 references indexed in Scilit:
- Sedative effects of antihistamines: safety, performance, learning, and quality of lifeClinical Therapeutics, 1997
- Histaminergic modulation of neocortical spindling and slow-wave activity in freely behaving ratsJournal of Neural Transmission, 1996
- Cortical Localization of Human Sustained Attention: Detection with Functional MR Using a Visual Vigilance ParadigmJournal of Computer Assisted Tomography, 1996
- Les méchanismes de l'eveil: du système réticulé mésencéphalique aux réseaux multiplesArchives of Physiology and Biochemistry, 1996
- Performance effects of antihistaminesJournal of Allergy and Clinical Immunology, 1990
- Differential cognitive effects of terfenadine and chlorpheniramineJournal of Allergy and Clinical Immunology, 1989
- Prolongation of simple and choice reaction times in a double-blind comparison of twice-daily hydroxyzine versus terfenadineJournal of Allergy and Clinical Immunology, 1989
- Effects of terfenadine on actual driving performance.Rinsho yakuri/Japanese Journal of Clinical Pharmacology and Therapeutics, 1988
- Distribution of the histaminergic neuron system in the central nervous system of rats; a fluorescent immunohistochemical analysis with histidine decar☐ylase as a markerBrain Research, 1984
- ANTIHISTAMINES AND SEDATIONThe Lancet, 1983