Cognitive abilities benzodiazepines

Few studies have examined the effects of benzodiazepines on other cognitive abilities. Rusted et al.170 reported that 5 and 10 mg diazepam impaired performance on a logical reasoning test, but had no effect on a mental rotation task. Judd et al.178 found that 30 mg flurazepam, but not 15 mg midazolam, impaired arithmetic (addition) abilities the day after drug administration. In contrast, flurazepam had no effect on reading comprehension. 

Prior use of benzodiazepines or opiates limits the psychotomimetic effects of ketamine. There has been a double-blind, placebo-controlled study of the role of lorazepam in reducing these effects after subanesthetic doses of ketamine in 23 volunteers who received lorazepam 2 mg or placebo, 2 hours before either a bolus dose of ketamine 0.26 mg/kg followed by an infusion of 0.65 mg/kg/hour or a placebo infusion (438). The ability of lorazepam to block the undesirable effects of ketamine was limited to just some effects. It reduced the ketamine-associated emotional distress and perceptual alterations, but exacerbated the sedative, attention-impairing, and amnesic effects of ketamine. However, it failed to reduce many of the cognitive and behavioral effects of ketamine. There were no pharmacokinetic interactions between subanesthetic doses of ketamine and lorazepam. 

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