BACKGROUND The spinal administration of some N-methyl-d-aspartate receptor antagonists results in antinociception and potentiates the effects of opioids and alpha2-adrenoceptor agonists, but ketamine and its enantiomers have not been examined. The present study investigated the interactions of racemic ketamine, R(-)-ketamine and S(+)-ketamine with morphine and with dexmedetomidine. METHODS In...

Aims: We aimed to compare the effects of anesthesia induction on hemodynamic parameters ketamine-midazolam or etomidate-midazolam combinations and coronary artery bypass grafting surgery.
 Material Methods: 40 adult patients undergoing CABG were randomly allocated into two groups for this prospective randomized double-blinded study. Ketamine group (n = 20) Etomidate 20). Intraoperative pos...

Antagonists of the N-methyl-D-aspartate (NMDA) receptors such as ketamine, induce abnormalities in healthy subjects similar to those found in schizophrenia. However, recent evidence, suggests that most of the currently known NMDA antagonists have a broader receptor profile than originally thought. Besides exerting an antagonistic effect on NMDA receptors, they have agonistic effects on dopamine...

This study compared acid-base and biochemical changes and quality of recovery in male cats with experimentally induced urethral obstruction and anesthetized with either propofol or a combination of ketamine and diazepam for urethral catheterization. Ten male cats with urethral obstruction were enrolled for urethral catheterization and anesthetized with either ketamine-diazepam (KD) or propofol ...

CONTEXT Existing therapies for major depression have a lag of onset of action of several weeks, resulting in considerable morbidity. Exploring pharmacological strategies that have rapid onset of antidepressant effects within a few days and that are sustained would have an enormous impact on patient care. Converging lines of evidence suggest the role of the glutamatergic system in the pathophysi...

Patients with major depressive disorder (MDD) have clinically relevant, significant decreases in bone mineral density (BMD). We sought to determine if predictive markers of bone inflammation-the osteoprotegerin (OPG)-RANK-RANKL system or osteopontin (OPN)-play a role in the bone abnormalities associated with MDD and, if so, whether ketamine treatment corrected the abnormalities. The OPG-RANK-RA...

BACKGROUND Little is known about the influence of ketamine and its enantiomers on cerebral haemodynamics, and there are no direct comparison reports. This study was designed to evaluate cerebrovascular responses to bolus injections of racemic, S(+)- and R(-)-ketamine in an established experimental model. METHODS Anaesthesia was induced with propofol in 14 pigs and maintained with fentanyl and...

AS part of the effort to develop mechanisms-based approaches to pain therapy, renewed interest has focused on the use of ketamine for treatment of acute and chronic pain. In particular, the role of N-methyl-D-aspartate (NMDA) excitatory glutamate receptors in nociceptive transmission has been established in humans. NMDA receptors participate in the development and maintenance of what can be cal...

OBJECTIVE To evaluate the effect of the mode of mechanical ventilation (MV) on the dose of intravenous anesthetic during 3 hours of ketamine/xylazine anesthesia. STUDY DESIGN Prospective laboratory study. ANIMALS Sixty-one adult male New Zealand White rabbits. METHODS Rabbits were anesthetized (ketamine/xylazine 35 + 5 mg kg(-1), IM), the trachea was intubated and randomized to four group...

In an abstract presented at the Society of Biological Psychiatry meeting in May, Lobna Ibrahim and Carlos Zarate of the National Institute of Mental Health reported that intravenous infusions of ketamine were effective in a majority of patients with highly treatment-resistant depression, i.e. even those who had been unresponsive to a course of electroconvulsive therapy. Editor’s note: Few treat...