Defining a PK and PD Model for Peripheral Analgesia After IV Oxytocin

Study Overview
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Brief Summary
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The goal of this clinical trial is to learn about oxytocin ( a naturally occurring hormone made in the brain that transmits messages) and the effects it may have on thermal heat pain after intravenous administration. The main question it aims to define is the time course of change in pain score after a 5 minute heating of the skin administered at intervals during and following infusion of intravenous oxytocin in order to create a Pharmacokinetic and a Pharmacodynamic model for oxytocin-induced analgesia. Participants will be asked to rate thermal heat temperatures before, during and after the intravenous infusion of oxytocin.

Detailed Description
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The primary objective is to define the time course of change in pain score after a 5 minute heating of the skin applied at intervals during and following infusion of intravenous oxytocin in order to create a Pharmacokinetic and Pharmacodynamic model for oxytocin-induced analgesia.

Official Title
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Defining a Pharmacokinetic and Pharmacodynamic Model for Peripheral Analgesia After Intravenous Oxytocin

Conditions
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Acute Pain, Chronic Pain, Healthy Volunteer

Intervention / Treatment
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* Drug: Oxytocin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female > 18 and < 75 years of age, Body Mass Index (BMI) <40. Generally in good health as determined by the Principal Investigator based on prior medical history, American Society of Anesthesiologists physical status 1, 2, or 3. For healthy volunteers, normal blood pressure (systolic 90-140 mmHg; diastolic 50-90 mmHg) resting heart rate 45-100 beats per minute) without medication. For knee arthritis subjects, normal blood pressure or, for those with hypertension, pressure controlled with anti-hypertensives and with a resting heart rate 45-100 beats per minute. Female subjects of child-bearing potential and those < 1 year post-menopausal, must be practicing highly effective methods of birth control such as hormonal methods (e.g., combined oral, implantable, injectable, or transdermal contraceptives), double barrier methods (e.g., condoms, sponge, diaphragm, or vaginal ring plus spermicidal jellies or cream), or total abstinence from heterosexual intercourse for a minimum of 1 full cycle before study drug administration. Exclusion Criteria: Hypersensitivity, allergy, or significant reaction to any ingredient of Pitocin® Any disease, diagnosis, or condition (medical or surgical) that, in the opinion of the Principal Investigator, would place the subject at increased risk (active gynecologic disease in which increased tone would be detrimental e.g., uterine fibroids with ongoing bleeding), compromise the subject's compliance with study procedures, or compromise the quality of the data Women who are pregnant (positive result for serum pregnancy test at screening visit), women who are currently nursing or lactating, women that have been pregnant within 2 years Subjects with neuropathy, chronic pain, diabetes mellitus, or taking benzodiazepines or pain medications on a daily basis. Subjects with current or history of ventricular tachycardia, atrial fibrillation or prolonged QT interval. Subjects with past or current history of hyponatremia or at risk for hyponatremia; anyone taking thiazide diuretics, loop diuretics, combination diuretics, lithium, carbamazepine, enalapril, Ramipril, celecoxib, temazepam, gliclazide, glimepiride, glibenclamide, glipizide, omeprazole, pantoprazole, desmopressin, SSRI's, MAOI, or the recreational drug ecstasy. Subjects with a known latex allergy. Subjects with a pain score rating of 1 or less during the initial training session to a 5 minute heating of 45°C- 47 °Celsius to the lower calf.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: Two 30 minute infusion of oxytocin, 17 micrograms with will be administered. The second infusion will be given 30 minutes after the completion of the first infusion.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intravenous Oxytocin<br>Two 30 minute infusion of oxytocin, 17 micrograms with will be administered. The second infusion will be given 30 minutes after the completion of the first infusion. | Drug: Oxytocin<br>* Intravenous oxytocin<br>* Other names: Pitocin;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain during sustained heat | Verbal pain score measured at one minute intervals during the 5 minute heating of the skin at 180 minutes after the initiation of the oxytocin infusions (baseline). Pain intensity report will be recorded each minute during the heating of the skin to 45 - 47 degrees Celsius . Pain will be determined using a Verbal Pain scale 0-10. 0 is equivalent to NO PAIN and 10 is equivalent to THE WORST PAIN IMAGINABLE. Heating temperature will be determined according to pain rating during screening visit. | 180 minutes after baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Acute pain, Chronic Pain, Oxytocin