title: Effects of isradipine, a dihydropyridine-class calcium channel antagonist, on D-methamphetamine-induced cognitive and physiological changes in humans.
abstract: D-methamphetamine is abused for its euphoric effects and stimulatory action on cognitive function. Its abuse can, however, be associated with massive hypertension resulting in strokes, ruptured aneurysms, or myocardial infarction. We examined the utility of isradipine, a dihydropyridine-class calcium channel antagonist, in treating d-methamphetamine induced hypertension and evaluated its effects on cognitive function, both of which are mediated by dopaminergic mechanisms. D-methamphetamine dose-dependently increased all vital signs (systolic, diastolic, and mean arterial pressure, and pulse rate) parameters. Isradipine significantly reduced d-methamphetamine-induced increases in diastolic and mean arterial pressure; however, this potentially beneficial therapeutic effect was offset by a significant reflex rise in pulse rate. D-methamphetamine also improved attention, accuracy of reasoning ability, and performance on computerized cognitive function tasks. D-methamphetamine's cognitive improving effects were not altered significantly by isradipine. Isradipine increased the false responding rate but was without significant effect on any other attentional task, or on reasoning ability, or performance. Isradipine does not appear to enhance cognitive function in healthy humans.
authors.affiliation: Department of Psychiatry, University of Texas-Health Science Center at San Antonio, San Antonio, TX 78284-7792, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Johnson
authors.forename: N
authors.initials: N
authors.lastname: Ait-Daoud
authors.forename: L T
authors.initials: LT
authors.lastname: Wells
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000188:drug therapy* / Q000503:physiopathology*; D002121:Calcium Channel Blockers / Q000008:administration & dosage*; D002320:Cardiovascular Physiological Phenomena / Q000187:drug effects*; D003071:Cognition / Q000187:drug effects* / Q000502:physiology*; D018592:Cross-Over Studies; D004095:Dihydropyridines / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D017275:Isradipine / Q000008:administration & dosage*; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage* / Q000009:adverse effects*; D008875:Middle Aged; D018697:Nootropic Agents / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D018697:Nootropic Agents; D008694:Methamphetamine; C038806:1,4-dihydropyridine; D017275:Isradipine