protocolSection identificationModule nctId: NCT06374771, orgStudyIdInfo id: MD-15-2022, briefTitle: Analgesic Effect of Melatonin and Vitamin C Administration, Alone or In Combination in Major Abdominal Surgery., statusModule overallStatus: NOT_YET_RECRUITING, startDateStruct date: 2024-04-27, primaryCompletionDateStruct date: 2024-06-27, completionDateStruct date: 2024-07-10, studyFirstPostDateStruct date: 2024-04-19, lastUpdatePostDateStruct date: 2024-04-19, sponsorCollaboratorsModule leadSponsor name: Cairo University, class: OTHER, collaborators name: Theodor Bilharz Research Institute, descriptionModule briefSummary: The goal of this clinical trial is to compare the analgesic effect of melatonin, and vitamin C and their combination in patients aged 18-60 years old who will undergo major abdominal surgery with mid-line incision within an expected time of surgery from 3 to 5 hours e.g. radical cystectomy, radical prostatectomy, colectomy, sigmoidectomy, splenectomy, and CBD exploration through mid-line incision.This study hypothesizes that using both vitamin C and melatonin together as adjuvants will cause:* More reduction in total morphine consumption in the first 24 hours postoperatively* More reduction of the incidence of chronic post-surgical pain, than using each adjuvant alone.Participants will be allocated into three equal groups: Melatonin (M group) and vitamin C (V group), and Melatonin and vitamin C (VM group). Two hours before surgery all patients will receive the study drugs orally and will be continued for 3 days postoperative at the same time of the first administration; 10mg of melatonin for M group (Melatonin 10 mg - Puritan's Pride premium company), 1gm of vitamin C for V group (Sanso C 1000 mg - AUG pharma company), and 10mg of melatonin and 1gm of vitamin C for VM group.Researchers will compare:* The effect of melatonin, vitamin C, and their combination on postoperative opioid consumption* The severity of postoperative pain, using the Numerical Rating Scale (NRS)* Patients' satisfaction with a three-point scale* The time of the first requirement for rescue analgesia* The effect on the incidence of chronic post-surgical pain., conditionsModule conditions: Postoperative Pain, designModule studyType: INTERVENTIONAL, phases: NA, designInfo allocation: RANDOMIZED, interventionModel: PARALLEL, primaryPurpose: PREVENTION, maskingInfo masking: QUADRUPLE, whoMasked: PARTICIPANT, whoMasked: CARE_PROVIDER, whoMasked: INVESTIGATOR, whoMasked: OUTCOMES_ASSESSOR, enrollmentInfo count: 60, type: ESTIMATED, armsInterventionsModule interventions name: Melatonin 10 MG, interventions name: Vitamin C, outcomesModule primaryOutcomes measure: Total morphine consumption, secondaryOutcomes measure: Numeric Rating Scale, secondaryOutcomes measure: Richmond Agitation Sedation Scale, secondaryOutcomes measure: Time to first analgesic request, secondaryOutcomes measure: chronic post-surgical pain, secondaryOutcomes measure: patient satisfaction using Likert three-point scale, secondaryOutcomes measure: systolic blood pressure, secondaryOutcomes measure: Heart rate, secondaryOutcomes measure: Intra-operative mean consumption of sevoflurane per hour., eligibilityModule sex: ALL, minimumAge: 18 Years, maximumAge: 65 Years, stdAges: ADULT, stdAges: OLDER_ADULT, contactsLocationsModule locations facility: Faculty of Medicine - Cairo University, city: Cairo, state: Manial, zip: 11553, country: Egypt, contacts name: Waleed Hamimy, MD, role: CONTACT, phone: 01150377770, phoneExt: +2, email: hamimy2002@gmail.com, geoPoint lat: 30.06263, lon: 31.24967, hasResults: False