title: Hemodynamic mechanisms underlying the incomplete tolerance to caffeine's pressor effects.
abstract: Blood pressure (BP) and cardiovascular hemodynamics were assessed at baseline and after caffeine administration in a 4-week, placebo-controlled, double-blind, randomized, crossover trial of caffeine tolerance formation. Half of the subjects developed tolerance to the pressor effect of caffeine, whereas the other half continued to show increases in BP after caffeine ingestion (F = 16.7, p <0.0001). In the subjects who did not develop tolerance, peripheral resistance increased incrementally as the daily dose of caffeine increased (F = 2.8, p = 0.05).
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA. noha-farag@ouhsc.edu
authors.forename: Noha H
authors.initials: NH
authors.lastname: Farag
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Vincent
authors.forename: Barbara S
authors.initials: BS
authors.lastname: McKey
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Whitsett
authors.forename: William R
authors.initials: WR
authors.lastname: Lovallo
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004361:Drug Tolerance; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
chemical_list: D014662:Vasoconstrictor Agents; D002110:Caffeine