Ketamine Hydrochloride is the hydrochloride salt of a synthetic derivative of cyclohexanone with analgesic and anesthetic activities. Although its mechanism of action is not well understood, ketamine appears to non-competitively block N-methyl-D-aspartate (NMDA) receptors and may interact with opioid mu receptors and sigma receptors, thereby reducing pain perception, inducing sedation, and producing dissociative anesthesia.