Central disinhibition is a mechanism involved in the physiopathology of fibromyalgia. Melatonin can improve sleep quality, pain and pain threshold. We hypothesized that treatment with melatonin alone or in combination with amitriptyline would be superior to amitriptyline alone in modifying the endogenous pain-modulating system (PMS) as quantified by conditional pain modulation (CPM), and this change in CPM could be associated with serum brain-derived neurotrophic factor (BDNF). We also tested whether melatonin improves the clinical symptoms of pain, pain threshold and sleep quality.

This study aimed to answer three questions related to chronic myofascial pain syndrome (MPS): 1) Is the motor cortex excitability, as assessed by transcranial magnetic stimulation parameters (TMS), related to state-trait anxiety? 2) Does anxiety modulate corticospinal excitability changes after evoked pain by Quantitative Sensory Testing (QST)? 3) Does the state-trait anxiety predict the response to pain evoked by QST if simultaneously receiving a heterotopic stimulus [Conditional Pain Modulation (CPM)]? We included females with chronic MPS (n = 47) and healthy controls (n = 11), aged 19 to 65 years. Motor cortex excitability was assessed by TMS, and anxiety was assessed based on the State-Trait Anxiety Inventory. The disability related to pain (DRP) was assessed by the Profile of Chronic Pain scale for the Brazilian population (B:PCP:S), and the psychophysical pain measurements were measured by the QST and CPM.

Transcranial direct current stimulation (tDCS) and melatonin can effectively treat pain. Given their potentially complementary mechanisms of action, their combination could have a synergistic effect. Thus, we tested the hypothesis that compared to the control condition and melatonin alone, tDCS combined with melatonin would have a greater effect on pain modulatory effect, as assessed by quantitative sensory testing (QST) and by the pain level during the Conditional Pain Modulation (CPM)-task. Furthermore, the combined treatment would have a greater cortical excitability effect as indicated by the transcranial magnetic stimulation (TMS) and on the serum BDNF level. Healthy males (n=20), (aged 18 to 40 years), in a blinded, placebo-controlled, crossover, clinical trial, were randomized into three groups: sublingual melatonin (0.25 mg/kg)+ a-tDCS, melatonin (0.25 mg/kg)+sham-(s)-tDCS, or sublingual placebo+s-tDCS. Anodal stimulation (2 mA, 20 min) was applied over the primary motor cortex. There was a significant difference in the heat pain threshold (°C) for melatonin+a-tDCS vs. placebo+s-tDCS (mean difference: 4.86, 95% confidence interval [CI]: 0.9 to 8.63) and melatonin+s-tDCS vs. placebo+s-tDCS (mean: 5.16, 95% CI: 0.84 to 8.36). There was no difference between melatonin+s-tDCS and melatonin+a-tDCS (mean difference: 0.29, 95% CI: −3.72 to 4.23). The mean change from the baseline on amplitude of motor evocate potential (MEP) was significantly higher in the melatonin+a-tDCS (−19.96%±5.2) compared with melatonin+s-tDCS group (−1.36%±5.35) and with placebo+s-tDCS group (3.61%±10.48), respectively (P<0.05 for both comparisons). While melatonin alone or combined with a-tDCS did not significantly affect CPM task result, and serum BDNF level. The melatonin effectively reduced pain; however, its association with a-tDCS did not present an additional modulatory effect on acute induced pain.

The purpose of this review was to search for articles on human studies investigating the relationship between melatonin and high-risk pregnancy. An electronic search was conducted in the MEDLINE and PubMed databases from September 2010 to October 2020. The initial search produced 441 articles in PubMed and 407 in MEDLINE. After sorting the titles and abstracts, and removing duplicates, we had nine articles in PubMed and three in Medline. The results of these studies mainly show that the association between melatonin receptor 1B polymorphisms and gestational diabetes mellitus is the most common physiological mechanism relating to melatonin and high-risk pregnancy in this review. In addition, the circadian rhythm, decreased melatonin production, and anti-inflammatory and antioxidant effects were explored. The findings of our review of the literature suggest that this indoleamine is essential in high-risk pregnancy for its potent anti-inflammatory and antioxidant effects, regulation of the circadian rhythm, and genic receptor expression.

O objetivo deste estudo foi avaliar o estoque domiciliar de medicamentos em comunidades atendidas pela Estratégia de Saúde da Família (ESF) em município localizado no Sul do Brasil. Foram amostrados 10% dos domicílios de cinco ESF. Os dados foram coletados por Agentes Comunitários de Saúde (ACS) através de questionário adaptado. A idade média dos entrevistados foi de 42 anos e dos moradores foi de 16 anos, destes 51% eram mulheres. Foi observada renda de 1 a 3 salários mínimos (69,1%), e escolaridade de 0 a 4 anos de estudo (42%). Dos domicílios visitados, 98,7% apresentavam pelo menos um medicamento estocado. Dos 533 lugares de guarda averiguados, 43,5% estava exposto ao calor, 39,6% a umidade, 16,5% a luz. Dos 2.717 medicamentos encontrados, 6,9% estavam vencidos, 35,3% não estavam dentro da embalagem secundária, quando esta se aplica, 67,9% não continham a presença de bula. Os fármacos analgésicos foram os mais prevalentes no estoque (21%). Os resultados nos levam a concluir que há necessidade de equipe multiprofissional para a promoção de saúde e a racionalização dos estoques domiciliares de medicamentos, sendo que o ACS é um profissional indispensável para a promoção do uso racional de medicamentos.