Calcitonin as an analgesic agent: review of mechanisms of action and clinical applications / Calcitonina como agente analgésico: revisão dos mecanismos de ação e das aplicações clínicas

Abstract Background and objectives: Calcitonin is a polypeptide hormone regulating the metabolism of calcium in the body. For many years calcitonin has been used to maintain and improve bone mineral density and to reduce the fracture rate. Many studies showed that calcitonin had analgesic role in several painful circumstances. This pain-ameliorating effect is irrelevant to its osteoclastic inhibitory effect and mechanisms like altering Na+ channel and serotonin receptor expression or hypothesis including the endorphin-mediated mechanism were used to explain this effect. In this study we performed a thorough review on the role of calcitonin as an analgesic agent in different scenarios and investigated the fact that calcitonin can be a feasible medication to relieve pain. Method: Many studies focused on the analgesic effect of calcitonin in several painful circumstances, including acute pains related to vertebral fractures, metastasis, migraine and reflex sympathetic dystrophy as well as neuropathic pains related to spinal injuries or diabetes, and phantom pain. Also, calcitonin was showed to be a useful additive to local anesthesia in the case of controlling postoperative pain or trigeminal neuralgia more effectively. However we faced some contradictory data for conditions like lumbar canal stenosis, complex regional pain syndrome, phantom pain and malignancies. Conclusion: This study showed that calcitonin could be helpful analgesic agent in different painful situations. Calcitonin can be considered an eligible treatment for acute pains related to vertebral fractures and a feasible alternative for the treatment of the acute and chronic neuropathic pains where other medications might fail.

Resumo Justificativa e objetivos: A calcitonina é um hormônio polipeptídico que regula o metabolismo do cálcio no organismo. Por muitos anos a calcitonina tem sido usada para manter e melhorar a densidade mineral óssea e reduzir a incidência de fraturas. Muitos estudos mostraram que a calcitonina teve efeito analgésico em várias condições físicas de dor. Esse efeito de melhoria da dor é irrelevante diante de seu efeito inibidor osteoclástico e de mecanismos, tais como a alteração do canal de Na+ e da expressão do receptor de serotonina, inclusive a hipótese do mecanismo mediado pela endorfina, que foram usados para explicar esse efeito. Neste estudo, fizemos uma revisão completa sobre o papel da calcitonina como agente analgésico em diferentes cenários e investigamos o fato de que a calcitonina pode ser uma medicação viável para aliviar a dor. Método: Muitos estudos centraram no efeito analgésico da calcitonina em várias condições de dor, inclusive dores agudas relacionadas a fraturas vertebrais, metástases, enxaqueca e distrofia simpática reflexa, bem como dores neuropáticas relacionadas a lesões medulares ou ao diabetes e dor fantasma. Além disso, a calcitonina mostrou ser um aditivo útil à anestesia local para o controle mais efecaz da dor pós-operatória ou neuralgia do trigêmeo. Porém, nos deparamos com alguns dados contraditórios em condições como estenose do canal lombar, síndrome complexa da dor regional, dor fantasma e malignidades. Conclusão: Este estudo mostrou que a calcitonina pode ser um analgésico útil em diferentes condições de dor. A calcitonina pode ser considerada um tratamento elegível para as dores agudas relacionadas a fraturas vertebrais e uma opção viável para o tratamento das dores neuropáticas agudas e crônicas em que outros medicamentos podem falhar.

Effect of Supplementary Administration of Anaheal on Reducing Pain, Swelling and Trismus after Mandibular Third Molar Surgery: A Splitmouth Controlled Randomized Clinical Trial

Objective: To evaluate the effect of supplementary administration of Anaheal capsule in reducing pain, swelling and trismus after surgical removal of impacted mandibular third molars. Material and Methods: This single-blind controlled randomized clinical trial was conducted on 36 patients referring to Tabriz University of Medical Sciences. Each of the 36 patients had bilateral surgical removal of mandibular third molars in two sessions, with at least a 4-week interval between sessions. In the same individual, one of the sites randomly received a test medication whereas the other site was used as a control. In the test subgroup (test medication side), the first dose of Anaheal capsule was given as a 200-mg dose of bromelain immediately after surgery according to manufacturer's instructions and the subsequent doses were given at 6-hour intervals after the first dose. The medication was administrated for 3 days. In the control subgroup (control side), Anaheal was not administered. The severities of pain, swelling and maximum mouth opening (MMO) were recorded one and three days postoperatively. Paired t-test and t-test for independent samples were used. Statistical significance was defined at p<0.05. Results: A total of 72 surgical extractions were performed; 36 procedures served as control and 36 cases received Anaheal. Pain, swelling and trismus of the patients were at the highest levels one day after surgery, which decreased on day 3. However, independent t-test showed no significant differences in pain, swelling and trismus after surgery between the study subgroups (p>0.05). Conclusion: Supplementary administration of Anaheal (800 mg bromelain daily) had no significant effect on decreasing pain, swelling and trismus at 1- and 3-day intervals after surgical removal of mandibular third molars.