Compared to placebo, oral or intravenous morphine is effective in reducing pain intensity in the short term, and reported side effects include constipation, sedation, fatigue, dizziness, sweating, difficulty urinating, confusion, itching, and breathing problems. would be N-methyl D-aspartate (NMDA) receptor antagonist ketamine and dextromethorphan have analgesic effects, but not memantine. Adverse events of ketamine were more significant than placebo and calcitonin and included decreased alertness, sedation, hallucinations, auditory and positional disturbance, and imbalance. The results related to the use of gabapentin (gabapentin) for pain relief were conflicting. However, gabapentin did not improve depression-level functioning or sleep quality. Compared to active control with benztropine mesylate, amitriptyline was not effective in PLP, and according to one study, dry mouth and dizziness were the most commonly reported adverse events. Regarding calcitonin and local anesthesia, the findings were different. Adverse events of calcitonin were headache, dizziness, drowsiness, nausea, vomiting, and feeling hot and cold, and most studies were limited by their small sample size. Many researchers have studied physiological mechanisms in response to pain, anatomical pathways and neurotransmitters such as 5-hydroxytryptamine, bradykinin, histamine, eicosanoids, leukotrienes, hydroxy acids and cytokinins related to pain function. Pain control or pain relief is one of the important goals in the treatment of diseases and is of particular importance to doctors, even if it is not pathologically curable, medical professionals use five general groups to reduce pain. Sometimes they use different painkillers and traditional pain reduction methods. Therefore, examining the pathophysiology of pain and the drugs effective in its control and summarizing the information and using it optimally, when necessary, can be useful to some extent.