Baseline plasma GABA: its relationship to the adverse effects of acute lorazepam administration on cognition in the elderly.
The GABA system is an active target for drugs to treat a variety of disorders and the availability of an indirect measure of central GABA activity would not only enhance psychiatric research, but also permit assessment of the pharmacodynamic effects of drugs designed to act on this system. The relationships between plasma baseline pre-drug GABA concentrations and cognitive impairments induced by an acute oral dose of lorazepam (0.5 and 1.0 mg) were investigated in 22 healthy elderly individuals. Partial correlations controlling for plasma lorazepam concentrations revealed no significant relationship between baseline plasma GABA levels and lorazepam-induced impairments on tests of cognitive functioning. Plasma GABA concentration does not appear to be a useful marker of susceptibility to benzodiazepine-induced cognitive toxicity in the elderly. Other approaches to estimating central GABA activity should be pursued.
Pomara
Nunzio
N
Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA. Pomara@nki.rfmh.org
Willoughby
Lisa M
LM
Sidtis
John J
JJ
Doraiswamy
P Murali
PM
Wesnes
Keith A
KA
Cooper
Thomas B
TB
Greenblatt
David J
DJ
D000339:Affect / Q000187:drug effects; D000368:Aged; D003071:Cognition / Q000187:drug effects*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D018757:GABA Modulators / Q000009:adverse effects* / Q000097:blood; D006801:Humans; D008140:Lorazepam / Q000009:adverse effects* / Q000097:blood; D008297:Male; D008568:Memory / Q000187:drug effects; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects; D005680:gamma-Aminobutyric Acid / Q000097:blood*
D018757:GABA Modulators; D005680:gamma-Aminobutyric Acid; D008140:Lorazepam