An update on pharmacological actions of drugs for neuropathic pain treatment

Pain normally serves as a warning and protective signal and is important for the survival of animals and humans. However, chronic neuropathic pain causes excruciating suffering that disrupts the quality of patients' lives. Chronic neuropathic pain remains a significant health problem because it is often resistant to conventional analgesics. Central sensitization is a common feature of neuropathic pain, but the cellular and molecular mechanisms underlying the abnormal sensory processing in neuropathic pain are not fully understood. In this article, we reviewed the efficacy and pharmacological actions of several classes of drugs, including opioids, antidepressants, anticonvulsants, and NMDA receptor antagonists, currently used to treat neuropathic pain in patients and animal models. Recent studies have provided substantial new information on the analgesic mechanisms of these drugs. We also have presented a critical review on current understanding of the pharmacological actions of commonly used analgesics for neuropathic pain treatment. Neuropathic pain with different etiologies likely requires different treatment strategies. Thus, patients with neuropathic pain should be examined using a comprehensive and integrated approach, and an individualized, mechanism-based treatment is needed to satisfactorily manage refractory neuropathic pain.