Acute lorazepam effects on neurocognitive performance

A double-blind, placebo-controlled, crossover design was employed to determine whether acute lorazepam (2 mg orally) cognitive side effects would emerge in a differential age-dependent fashion in 15 young (mean age=22 years) and 12 older (mean age=64 years) subjects. Acute use of lorazepam is frequently the initial treatment choice for convulsive status epilepticus or repetitive seizure clusters. Cognitive assessment was performed during drug and placebo conditions using a computerized battery of cognitive tests. With the exception of performance on the reasoning composite score, significant drug effects were present on all primary cognitive domain measures. However, the only significant drug-by-age interaction effect was seen for dual-task performance. The relationship between test performance and plasma lorazepam concentrations was generally modest and non-significant, suggesting that individual differences in pharmacokinetics are not a major factor contributing to the emergence of cognitive side effects. Despite robust lorazepam effects on multiple measures of neurocognitive function, differential age effects are largely restricted to dual-task performance. These results indicate that with the exception of dual-task performance, older individuals in the age range of this study do not appear to be at increased risk for the emergence of cognitive side effects following a single 2-mg dose of lorazepam.