ABSTRACT
Pain is classified by various descriptions. Chronic pain has been described as being neuropathic (due to nervous system lesions), nociceptive (due to tissue damage), or mixed (a combination of neuropathic and nociceptive). The addition of the term nociplastic pain is used to describe patients who experience chronic pain without tissue damage or nervous system lesions. Chronic pain is often difficult to manage, particularly neuropathic pain. Evidence-based pharmacological treatment options include anticonvulsants and antidepressants. The choice of medication will depend on various factors, including patient profile, type of pain, and associated conditions. Medications with the best evidence of efficacy for first-line use in neuropathic pain are the gabapentinoids, carbamazepine, the tricyclic antidepressants, and the serotonin-noradrenaline reuptake inhibitors duloxetine and venlafaxine. The cannabinoids and ketamine are being actively investigated for use in chronic pain. Currently the cannabinoids'potential benefit is outweighed by the adverse effects, and recommendations for the use of ketamine is limited by its parenteral route of administration and low evidence of efficacy in chronic pain