Ketamine as an analgesic in adults and children
Ketamine is a noncompetitive N-methyl D-aspartate (NMDA) receptor antagonist that blocks the release of excitatory neurotransmitter glutamate and provides anesthesia, amnesia, and analgesia by virtue of decreasing central sensitization. Various researches suggest the usefulness of ketamine as a strong analgesic used in sub anesthetic intravenous doses, and also as a sedative.
Additionally, ketamine has anti-tolerance, anti-hyperalgesia and anti-allodynia properties. Main components of opioid resistance and pathological pain are tolerance, hyperalgesia and allodynia phenomena which is mostly observed in the clinical conditions such as neuropathic pain, opioid-induced hyperalgesia, and central sensitization with allodynia or hyperalgesia. However, treatment of all these conditions are pretty much risky.
No major adverse effects of ketamine have been reported. Ketamine is used to treat acute pain after significant tissue trauma, either as the result of surgery or an accident. Its acts by noncompetitive antagonism of NMDA receptors. It also interacts with opioid receptors, monoamine, cholinergic, purinergic and adrenoreceptor systems as well as having local anesthetic effects
Further studies are necessary to evaluate the role of ketamine in the immediate postoperative period after surgical interventions known to produce severe pain and in the chronic pain prevention and treatment.