Analgesic Potentials of Preoperative Pregabalin,Magnesium Sulphate and Their Combination in Acute Post-thoracotomy Pain

Study Overview
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Brief Summary
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This study evaluates the effect of giving preoperative adjuvant drug as pregabalin or magnesium sulphate or a combination of both drugs to decrease postoperative morphine consumption and pain intensity in the first 24 hours in postoperative period . quarter of patients receive single dose oral pregabalin 300mg 1 hour preoperatively ,other quarter receive single intravenous Magnesium sulphate 50mg per Kg over 200ml saline over 20 minutes preoperatively , other quarter receive combination of both drugs , the last quarter receive placebo drugs . All patients receive 0.1mg per Kg intravenous morphine sulphate intraoperatively

Detailed Description
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Magnesium (Mg) acts on N-methyl-D-aspartate (NMDA) receptor as a non-competitive antagonist with antinociceptive effects. Gabapentin is an alkylated analogue of gammaaminobutyric acid (GABA) developed primarily as an anticonvulsant drug. It was described as an analgesic drug for the treatment of neuropathic pain in the 1990s. Although it is named Gabapentin,it does not bind at the GABA A or GABA B receptor. It binds with high affinity for the α2δ subunit of the presynaptic voltage-gated calcium channels, which reduce calcium-dependent release of pro-nociceptive neurotransmitters in the pain pathways. Pregabalin is a structural analogue of GABA was introduced after Gabapentin. If we used these drugs in combination to opioids preoperatively as preventive analgesia may decrease postoperative opioid consumption and pain intensity.

Official Title
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Analgesic Potentials of Preoperative Oral Pregabalin,Intravenous Magnesium Sulphate and Their Combination in Acute Post-thoracotomy Pain.(Randomized,Double-Blind Study)

Conditions
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Postoperative Pain

Intervention / Treatment
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* Drug: Pregabalin & Placebo
* Drug: Magnesium sulphate & Placebo
* Drug: Pregabalin & Magnesium sulphate
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA status of1 or 2 Patients undergoing thoracotomy Body mass index (BMI): Less than forty and more than twenty. Exclusion Criteria: - 1. Known sensitivity or contraindication to drugs used in the study. 2. History of psychological disorders and/or chronic pain. 3. Patients receiving medical therapies that are considered to result in tolerance to opioids. 4. Significant liver or kidney diseases that will affects the pharmacokinetics of study drugs.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Pregabalin & placebo<br>: will receive single dose oral Pregabalin 300 mg one hour preoperative and 200 ml of normal saline over 20 min. | Drug: Pregabalin & Placebo<br> <br> |
| Active Comparator: Magnesium sulphate & Placebo<br>will receive preoperative single dose IV Magnesium Sulphate 50mg /kg infused over 20 minutes diluted in 200 ml normal saline and a placebo capsule similar to pregabalin 300 mg. | Drug: Magnesium sulphate & Placebo<br> <br> |
| Active Comparator: Pregabalin & Magnesium sulphate<br>: will receive single dose oral pregabalin 300mg one hour preoperative and single dose IV Magnesium Sulphate 50mg /kg infused over 20 minutes diluted in 200 ml normal saline. | Drug: Pregabalin & Magnesium sulphate<br> <br> |
| Placebo Comparator: Placebo<br>will receive placebo medications at the same time and route of administration of other groups. | Drug: Placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total morphine consumption | patients are given regular intravenous morphine through patient controlled analgesia (PCA) and morphine consumption calculated from the PCA device | First 24 hours in postoperative period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain intensity using Visual Analogue Scale | Assessment of pain intensity every 4 hours in the first 24 hours in postoperative period | First 24 hours in postoperative period | 
| Recovery Time | Time taken for recovery of the patient to be fully awake | Immediately after ending the surgery | 
| Heart Rate | Assessment of Heart Rate every 4 hours | First 24 hours in postoperative period | 
| Blood Pressure | Assessment of Blood Pressure every 4 hours | First 24 hours in postoperative period | 
| Oxygen saturation | Assessment of Oxygen saturation every 4 hours | First 24 hours in postoperative period | 
| Respiratory Rate | Assessment of Respiratory Rate every 4 hours | First 24 hours in postoperative period | 
| Postoperative nausea and vomiting | Postoperative nausea and vomiting scale (none 0, mild 1, moderate 2 , sever 3) | First 24 hours in postoperative period | 
| Side effects from the used drugs |  | First 24 hours in postoperative period | 
| Sedation score | Using Ramsay Sedation score | First 24 hours in postoperative period |