title: Influences of caffeine, acetazolamide and cognitive stimulation on cerebral blood flow velocities.
abstract: Assessment of cerebral blood flow velocities (CBFV) can be used as a non-invasive tool to evaluate specific drug effects, like caffeine (CAF), acetazolamide (AA) as well as cognition. Their influences on each others CBFV were evaluated in detail, using a randomized, double-blind, double-dummy, placebo-controlled three-fold cross-over study design in 18 right-handed healthy male volunteers. CBFV (maximal, mean, minimal) and pulsatility index of both middle cerebral arteries were recorded by transcranial Doppler ultrasound simultaneously, during a verbal memory test, oral CAF, intravenous AA or placebo. AA led to increase in CBFV of 25-32%. Caffeine resulted in decreased V(mean) and V(min) of 10-13%. Cognitive stimulation resulted in a slight increase of CBVF of about 4%, but was overruled by effects of AA and CAF. We conclude that pharmacological effects can easily be assessed by TCD during clinical pharmacological studies of vasoactive drugs. However intraindividual variability and effects of neuropsychological stimulation needs to be taken into account.
authors.affiliation: Institute of Clinical Pharmacology, Pharma Research Center, Bayer HealthCare AG, D-42096 Wuppertal, Germany. haase.claus@kk-recklinghausen.de
authors.forename: Claus G
authors.initials: CG
authors.lastname: Haase
authors.forename: Michael
authors.initials: M
authors.lastname: Becka
authors.forename: Jochen
authors.initials: J
authors.lastname: Kuhlmann
authors.forename: Georg
authors.initials: G
authors.lastname: Wensing
mesh_terms: D000086:Acetazolamide / Q000494:pharmacology*; D000328:Adult; D000927:Anticonvulsants / Q000494:pharmacology*; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects; D011594:Psychometrics; D015656:Respiratory Mechanics / Q000187:drug effects; D017585:Ultrasonography, Doppler, Transcranial; D014706:Verbal Learning / Q000187:drug effects
chemical_list: D000927:Anticonvulsants; D000697:Central Nervous System Stimulants; D002110:Caffeine; D000086:Acetazolamide