Progress in neuro-psychopharmacology & biological psychiatry
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Prog. Neuropsychopharmacol. Biol. Psychiatry · Aug 2019
Randomized Controlled TrialNeurocognitive performance under combined regimens of ketamine-dexmedetomidine and ketamine-fentanyl in healthy adults: A randomised trial.
Analgesic doses of ketamine affects neurocognition; however, deficits under co-administration regimens are unknown. This study evaluated the effects of ketamine, alone and in combination with dexmedetomidine or fentanyl on neurocognition. Using a randomised, within-subjects gender stratified design, 39 participants (mean age = 28.4, SD ± 5.8) received a ketamine bolus of 0.3 mg/kg followed by 0.15 mg/kg/h infusion of ketamine (3 h duration). ⋯ Ketamine, norketamine and dexmedetomidine concentrations were modestly associated with reduced psychomotor speed and accuracy (all p < .05), and an inverse relationship was found between blood concentrations of ketamine, norketamine and dexmedetomidine and performance on memory tasks. Co-administration of ketamine with dexmedetomidine but not with fentanyl exerts synergistic effects on psychomotor performance and memory without executive dysfunction. Assessment of these effects in clinical groups is warranted.