BACKGROUND The studies on the mechanisms of ketamine antinociception have led to conflicting results. In this study, the authors investigated the contribution of supraspinal monoaminergic descending inhibitory system to ketamine analgesia for acute nociception and inflammation-induced hyperalgesia. METHODS Male Sprague-Dawley rats were used. The paw withdrawal latencies to radiant heat stimul...

OBJECTIVES Ketamine is commonly used in anesthetic and sedation before surgical procedures and acts as an analgesic in smaller doses. The aim of this study was to assess the effects of intranasal (IN) ketamine in patients with moderate to severe limb trauma (visual analog scale (VAS) > 60 mm). METHODS In a triple-blind randomized controlled clinical trial; 154 patients with isolated orthopedi...

The aim of this study was to investigate the effect of ketamine and midazolam on preventing the development of morphine tolerance and dependence and withdrawal syndrome in mice. In the present study different groups of mice were received morphine (50 mg/kg, s.c.), morphine (50 mg/kg, s.c.) + ketamine (25, 50, 75 mg/kg, i.p.) , morphine (50 mg/kg , s.c.) + midazolam (0.5, 1, 2 mg/kg, i.p.) , mor...

Background: Major depressive disorder is a severe, heterogeneous, common medical illness and a leading cause of disability throughout the world that poses a significant public health issue. Previous studies have shown rapid antidepressant effects following a single administration of ketamine. This study aimed to assess the impact of route of administration and dose of ketamine for the reduction...

This study aimed to determine the anesthetic efficacy of intranasal medetomidine/ketamine and diazepam/ketamine combinations in New Zealand White rabbits. For this purpose, 12 adult rabbits weighing 2.3‐4.1 kg were used by randomly dividing animals into two groups six animals: Medetomidine ‐ Ketamine (MK) Diazepam (DK). Intranasally, medetomidine (0.2 mg kg‐1) ketamine (10 combination was admin...

BACKGROUND Ketamine inhibits the activation of both heteromeric and homomeric nicotinic acetylcholine receptors. The site of molecular interaction is unknown. METHODS The inhibition of alpha7 nicotinic acetylcholine receptors by ketamine was compared to that of 5-hydroxytryptamine-3A (5HT3A) receptors that are resistant to ketamine inhibition in Xenopus laevis oocytes. To determine whether th...

BACKGROUND Surprising clinical evidence suggests a block of sympathetic transmission by ketamine. The action of ketamine on nicotinic acetylcholine receptors (nAChRs) in human ganglions is unknown. Because ganglionic transmission depends on nAChRs, such information may help to clarify whether ketamine impairs ganglionic transmission in men. Because racemic ketamine as well as S(+)-ketamine are ...

BACKGROUND Ketamine is a non-barbiturate anesthetic agent which has various effects on the cardiovascular system. Among them, ketamine is known for its hypotensive properties. The hypotension is thought to be mediated by a direct effect on vascular smooth muscles. This study is designed to examine the effects of ketamine on KCl- and histamine-induced contraction in isolated rabbit renal arterie...

BACKGROUND Low-dose ketamine behaves as an analgesic in the treatment of acute and chronic pain. To further understand ketamine's therapeutic profile, the authors performed a population pharmacokinetic-pharmacodynamic analysis of the S(+)-ketamine analgesic and nonanalgesic effects in healthy volunteers. METHODS Ten men and ten women received a 2-h S(+)-ketamine infusion. The infusion was inc...

BACKGROUND The effect of ketamine on vasodilation mediated by adenosine triphosphate (ATP)-sensitive K(+) channels has not been studied. The present study was designed to determine whether ketamine might stereoselectively affect vasorelaxation induced by an ATP-sensitive K(+) channel opener in the isolated rat aorta. METHODS Rings of the rat aorta with or without endothelium were suspended fo...