Triazolam and zolpidem: effects on human memory and attentional processes.
BACKGROUND
The imidazopyridine hypnotic zolpidem may produce less memory and cognitive impairment than classic benzodiazepines, due to its relatively low binding affinity for the benzodiazepine receptor subtypes found in areas of the brain which are involved in learning and memory.


OBJECTIVE
The study was designed to compare the acute effects of single oral doses of zolpidem (5, 10, 20 mg/70 kg) and the benzodiazepine hypnotic triazolam (0.125, 0.25, and 0.5 mg/70 kg) on specific memory and attentional processes.


METHODS
Drug effects on memory for target (i.e., focal) information and contextual information (i.e., peripheral details surrounding a target stimulus presentation) were evaluated using a source monitoring paradigm, and drug effects on selective attention mechanisms were evaluated using a negative priming paradigm, in 18 healthy volunteers in a double-blind, placebo-controlled, crossover design.


RESULTS
Triazolam and zolpidem produced strikingly similar dose-related effects on memory for target information. Both triazolam and zolpidem impaired subjects' ability to remember whether a word stimulus had been presented to them on the computer screen or whether they had been asked to generate the stimulus based on an antonym cue (memory for the origin of a stimulus, which is one type of contextual information). The results suggested that triazolam, but not zolpidem, impaired memory for the screen location of picture stimuli (spatial contextual information). Although both triazolam and zolpidem increased overall reaction time in the negative priming task, only triazolam increased the magnitude of negative priming relative to placebo.


CONCLUSIONS
The observed differences between triazolam and zolpidem have implications for the cognitive and pharmacological mechanisms underlying drug-induced deficits in specific memory and attentional processes, as well for the cognitive and brain mechanisms underlying these processes.
Mintzer
M Z
MZ
Department of Psychiatry and Behavioral Sciences, Behavioral Biology Research Center, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA. mmintzer@jhmi.edu
Griffiths
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D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects*; D008875:Middle Aged; D011597:Psychomotor Performance / Q000187:drug effects; D011725:Pyridines / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D014229:Triazolam / Q000008:administration & dosage / Q000494:pharmacology*; D000077334:Zolpidem
D006993:Hypnotics and Sedatives; D011725:Pyridines; D014229:Triazolam; D000077334:Zolpidem