Morphine is a potent analgesic agent used to control acute or chronic pain. Chronic administration of morphine results in analgesic tolerance, hyperalgesia, and other side effects including dependence, addiction, respiratory depression, and constipation, which limit its clinical usage. Therefore, identifying the new analgesics with fewer side effects which could increase the effect of morphine and reduce its side effects is crucial. Melatonin, a multifunctional molecule produced in the body, is known to play an important role in pain regulation. The strong anti‐inflammatory effect of melatonin is suggested to be involved in the attenuation of the pain associated with inflammation. Melatonin also increases the anti‐nociceptive actions of opioids, such as morphine, and reverses their tolerance through regulating several cellular signaling pathways. In this review, published articles evaluating the effect of the co‐consumption of melatonin and morphine in different conditions were investigated. Our results show that melatonin has pain‐killing properties when administered alone or in combination with other anti‐nociceptive drugs. Melatonin decreases morphine consumption in different pathologies. Furthermore, attenuation of morphine intake can be accompanied by reduction of morphine‐associated side‐effects, including physical dependence, morphine tolerance, and morphine‐related hyperalgesia. Therefore, it is reasonable to believe that the combination of melatonin with morphine could reduce morphine‐induced tolerance and hyperalgesia, which may result from anti‐inflammatory and antioxidant properties of melatonin. Overall, we underscore that, to further ameliorate patients' life quality and control their pain in various pathological conditions, melatonin deserves to be used with morphine by anesthesiologists in clinical practice.

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褪黑激素和吗啡：共同使用的潜在有益影响

吗啡是一种强效镇痛剂，用于控制急性或慢性疼痛。长期服用吗啡会导致镇痛耐受、痛觉过敏和其他副作用，包括依赖、成瘾、呼吸抑制和便秘，这限制了其临床使用。因此，寻找新的副作用更少的镇痛药，可以增加吗啡的作用，减少其副作用是至关重要的。褪黑激素是一种在体内产生的多功能分子，已知在疼痛调节中起着重要作用。褪黑激素的强抗炎作用被认为与减轻与炎症相关的疼痛有关。褪黑激素还增加阿片类药物（如吗啡）的抗伤害作用，并通过调节多种细胞信号通路来逆转其耐受性。在这篇综述中，研究了评估褪黑激素和吗啡在不同条件下共同食用的影响的已发表文章。我们的结果表明，褪黑激素单独给药或与其他抗伤害性药物联合给药时具有止痛作用。褪黑激素减少不同病理中的吗啡消耗。此外，减少吗啡摄入量可以减少吗啡相关的副作用，包括身体依赖、吗啡耐受和吗啡相关的痛觉过敏。因此，有理由相信褪黑激素与吗啡的组合可以降低吗啡诱导的耐受性和痛觉过敏，这可能是由于褪黑激素的抗炎和抗氧化特性。总的来说，我们强调，为了进一步改善患者的