***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose Our intention was to assess the effectiveness of preoperative oral melatonin medication on sedation , sleep quality , and postoperative analgesia in patients undergoing elective prostatectomy . Methods Fifty-two ASA I – II patients undergoing elective prostatectomy were included in this study , r and omly divided into two groups . Patients received an oral placebo ( n = 26 ) or 6 mg melatonin ( n = 26 ) the night before and 1 h before surgery . All patients received a st and ard anesthetic protocol . At the end of surgery , all patients received tramadol i.v . via a PCA device . Extubation time , intraoperative fentanyl consumption , and recovery time were assessed at the end of the operation . Pain scores , tramadol consumption , and sedation scores were assessed at 1 , 2 , 4 , 6 , 12 , 18 , and 24 h postoperatively , and sleep quality and subjective analgesic efficacy were assessed at 24 h after surgery . Results There were no significant differences in demographic data between the groups . Extubation time and recovery time from anesthesia were significantly longer in the melatonin group ( P < 0.05 ) . Intraoperative fentanyl usage , pain scores , and tramadol consumption were significantly lower in the melatonin group ( P < 0.05 ) . The postoperative sleep quality of patients was significantly better in the melatonin group than in the control group ( P < 0.05 ) . Postoperative VAS of pain was significantly lower in the melatonin group compared with the control group at 1 , 2 , 4 , 6 , 12 , 18 , and 24 h postoperatively ( P < 0.05 ) . Subjective analgesic efficacy of patients was significantly different between groups ( P < 0.05 ) . The sedation scores were significantly higher in the melatonin group than in the control group at 1 h and 2 h after surgery ( P < 0.05 ) . Conclusions Preoperative oral melatonin administration decreased pain scores and tramadol consumption and enhanced sleep quality , sedation scores , and subjective analgesic efficacy during the postoperative period BACKGROUND Electroencephalography ( EEG ) is a useful diagnostic tool in the diagnosis of seizure and differentiating it from seizure-like attacks . Cooperation and immobility of the patient is crucial and in children who do not naturally sleep , pharmacological agents and procedural sedation should be used for sleep inducement . The purpose of this study was to compare efficacy and safety of melatonin and intravenous solution of midazolam administered orally in sedation induction for EEG of children . METHODS In a parallel single-blinded r and omized clinical trial , sixty 1 - 8 year old children who were referred to EEG Unit of Shahid Sadoughi Hospital , Yazd , Iran from September 2011 to March 2012 were evaluated . The Children were r and omly assigned into two groups to receive orally 0.3 mg/kg melatonin or 0.75 mg/kg ampoule of midazolam . The primary outcome was efficacy in adequate sedation ( Ramsay sedation score of four ) and recording of EEG . Secondary outcome was clinical side effects . RESULTS Nineteen girls ( 31.7 % ) and 41 boys ( 68.3 % ) with the mean age of 2.8 ± 1.8 years were evaluated .  Adequate sedation and recording of EEG was achieved in 36.7 % of midazolam group and in 73.3 % of melatonin group , ( p = 0.004 ) . Transient agitation was seen in 6.6 % of midazolam group . No significant difference was observed from the viewpoint of side effects frequency between the two drugs , ( p = 0.15 ) . CONCULSION Melatonin is a safe and an effective drug in sedation induction for EEG in children AIM Melatonin has been proposed as a premedication alternative to midazolam , preceding anaesthesia induction . However , to our knowledge , data concerning interaction between melatonin and intravenous anaesthetic drugs in children are not available . The aim of this prospect i ve , r and omized , double-blind pilot study was to investigate the possible effect of melatonin premedication , in comparison to midazolam , on the required infusion of propofol in children undergoing surgery . As a secondary outcome , the effect of oral melatonin on the preoperative sedation level and on the post anaesthesia recovery score was evaluated . METHODS Children between the age of 5 and 14 years , scheduled for elective surgery , were prospect ively enrolled between January 2012 and December 2013 , and r and omly assigned to two groups based on whether they received oral melatonin ( 0.5 mg/kg ) or oral midazolam ( 0.5 mg/kg ) premedication before induction of anaesthesia with propofol .  Degree of sedation before and after anaesthesia was also evaluated . RESULTS Ninety-two patients were studied , 46 for each group . We found that oral administration of melatonin significantly reduced doses of propofol required for induction of anaesthesia in paediatric patients , more than midazolam ( P < 0.001 ) . No statistically significant differences were found in the pre- and post-anaesthesia sedation score ( P = 0.387 and P = 0.525 , respectively ) between the two groups . CONCLUSIONS The present study demonstrates that melatonin enhances the potency of propofol also in paediatric patients . Moreover , considering the paediatric level of sedation , melatonin was equally as effective as midazolam . These data support the use of melatonin as a premedicant in paediatric surgical patients Fibromyalgia syndrome ( FMS ) is a chronic musculoskeletal disorder characterized by generalized muscular pain accompanied by fatigue and tenderness at specific anatomic sites called tender points . Although preliminary evidence indicates that melatonin may be effective in treating the pain associated with FMS , no definitive evidence supports this cl aim . This study was design ed to evaluate the significance of using different doses of melatonin , alone or in combination with fluoxetine for the management of FMS . A double-blind , placebo-controlled clinical study was performed on 101 patients ( 95 women and 6 men ) who fulfilled the criteria of the American College of Rheumatology ( ACR ) of FMS . The patients were r and omized into four groups : group A ( 24 patients ) treated with 20 mg/day fluoxetine alone ; group B ( 27 patients ) treated with melatonin 5 mg alone ; group C ( 27 patients ) treated with 20 mg fluoxetine plus 3 mg melatonin ; group D ( 23 patients ) treated with 20 mg fluoxetine plus 5 mg melatonin . Both drugs were given once daily in the morning and night time , respectively , for 8 wk . Each patient was clinical ly evaluated through direct interview with the patients using the Fibromyalgia Impact Question naire ( FIQ ) at zero time and after 8 wk . Using melatonin ( 3 mg or 5 mg/day ) in combination with 20 mg/day fluoxetine result ed in significant reduction in both total and different components of FIQ score compared to the pretreatment values . In conclusion , administration of melatonin , alone or in a combination with fluoxetine , was effective in the treatment of patients with FMS The MARIA r and omized trial evaluated the efficacy and safety of melatonin for the reduction of reperfusion injury in patients undergoing revascularization for ST-elevation myocardial infa rct ion ( STEMI ) . This was a prespecified interim analysis . A total of 146 patients presenting with STEMI within 6 hours of chest pain onset were r and omized to receive intravenous and intracoronary melatonin ( n=73 ) or placebo ( n=73 ) during primary percutaneous coronary intervention ( PPCI ) . Primary endpoint was myocardial infa rct size as assessed by magnetic resonance imaging ( MRI ) at 6 ± 2 days . Secondary endpoints were changes in left ventricular volumes and ejection fraction ( LVEF ) at 130 ± 10 days post-PPCI and adverse events during the first year . No significant differences in baseline characteristics were observed between groups . MRI was performed in 108 patients ( 86.4 % ) . Myocardial infa rct size by MRI evaluated 6 ± 2 days post-PPCI , did not differ between melatonin and placebo groups ( P=.63 ) . Infa rct size assessed by MRI at 130 ± 10 days post-PPCI , performed in 91 patients ( 72.8 % ) , did not show statistically significant differences between groups ( P=.27 ) . The recovery of LVEF from 6 ± 2 to 130 ± 10 days post-PPCI was greater in the placebo group ( 60.0 ± 10.4 % vs 53.1 ± 12.5 % , P=.008 ) . Both left ventricular end-diastolic and end-systolic volumes were lower in the placebo group ( P=.01 ) . The incidence of adverse events at 1 year was comparable in both groups ( P=.150 ) . Thus , in a nonrestricted STEMI population , intravenous and intracoronary melatonin was not associated with a reduction in infa rct size and has an unfavourable effect on the ventricular volumes and LVEF evolution . Likewise , there is lack of toxicity of melatonin with the doses used Background A relevant innovation about sedation of long-term Intensive Care Unit ( ICU ) patients is the ‘ conscious target ’ : patients should be awake even during the critical phases of illness . Enteral sedative administration is nowadays unusual , even though the gastrointestinal tract works soon after ICU admission . The enteral approach can not produce deep sedation ; however , it is as adequate as the intravenous one , if the target is to keep patients awake and adapted to the environment , and has fewer side effects and lower costs . Methods / Design A r and omized , controlled , multicenter , single-blind trial comparing enteral and intravenous sedative treatments has been done in 12 Italian ICUs . The main objective was to achieve and maintain the desired sedation level : observed RASS = target RASS ± 1 . Three hundred high-risk patients were planned to be r and omly assigned to receive either intravenous propofol/midazolam or enteral melatonin/hydroxyzine/lorazepam . Group assignment occurred through online minimization process , in order to balance variables potentially influencing the outcomes ( age , sex , SAPS II , type of admission , kidney failure , chronic obstructive pulmonary disease , sepsis ) between groups . Once per shift , the staff recorded neurological monitoring using vali date d tools . Three flowcharts for pain , sedation , and delirium have been proposed ; they have been design ed to treat potentially correctable factors first , and , only once excluded , to administer neuroactive drugs . The study lasted from January 24 to December 31 , 2012 . A total of 348 patients have been r and omized , through a central ized website , using a specific software expressly design ed for this study . The created network of ICUs included a mix of both university and non-university hospitals , with different experience in managing enteral sedation . A dedicated free-access website was also created , in both Italian and English , for continuous education of ICU staff through CME courses . Discussion This ‘ educational research ’ project aims both to compare two sedative strategies and to highlight the need for a profound cultural change , improving outcomes by keeping critically-ill patients awake . Trial registration number Clinical trials.gov # Background Previous studies have suggested that melatonin may produce antinociception through peripheral and central mechanisms . Based on the preliminary encouraging results of studies of the effects of melatonin on pain modulation , the important question has been raised of whether there is a dose relationship in humans of melatonin on pain modulation . Objective The objective was to evaluate the analgesic dose response of the effects of melatonin on pressure and heat pain threshold and tolerance and the sedative effects . Methods Sixty-one healthy subjects aged 19 to 47 y were r and omized into one of four groups : placebo , 0.05 mg/kg sublingual melatonin , 0.15 mg/kg sublingual melatonin or 0.25 mg/kg sublingual melatonin . We determine the pressure pain threshold ( PPT ) and the pressure pain tolerance ( PPTo ) . Quantitative sensory testing ( QST ) was used to measure the heat pain threshold ( HPT ) and the heat pain tolerance ( HPTo ) . Sedation was assessed with a visual analogue scale and bispectral analysis . Results Serum plasma melatonin levels were directly proportional to the melatonin doses given to each subject . We observed a significant effect associated with dose group . Post hoc analysis indicated significant differences between the placebo vs. the intermediate ( 0.15 mg/kg ) and the highest ( 0.25 mg/kg ) melatonin doses for all pain threshold and sedation level tests . A linear regression model indicated a significant association between the serum melatonin concentrations and changes in pain threshold and pain tolerance ( R2 = 0.492 for HPT , R2 = 0.538 for PPT , R2 = 0.558 for HPTo and R2 = 0.584 for PPTo ) . Conclusions The present data indicate that sublingual melatonin exerts well-defined dose-dependent antinociceptive activity . There is a correlation between the plasma melatonin drug concentration and acute changes in the pain threshold . These results provide additional support for the investigation of melatonin as an analgesic agent . Brazilian Clinical Trials Registry ( ReBec ) : ( U1111 - 1 
    Output:
    
The pooling data show that melatonin significantly decreased the pain intensity , as evidence d by the pain scores .
Moreover , melatonin administration also reduced the proportion of patients with analgesic requirements and BDNF levels .
Collectively , the current meta- analysis supports the use of melatonin for anti-nociception