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

Wake Forest University (WFU)

Status and phase: Completed; Phase 2

Conditions: Chronic Pain; Healthy Volunteer; Acute Pain

Treatments: Drug: Oxytocin

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT05929339

IRB00097699

1P01NS119159-01A1 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

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.

Full description

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.

Enrollment: 25 patients

Sex: All

Ages: 18 to 75 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. Male or female > 18 and < 75 years of age, Body Mass Index (BMI) <40.
2. 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.
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.
4. 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

1. Hypersensitivity, allergy, or significant reaction to any ingredient of Pitocin®
2. 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
3. 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
4. Subjects with neuropathy, chronic pain, diabetes mellitus, or taking benzodiazepines or pain medications on a daily basis.
5. Subjects with current or history of ventricular tachycardia, atrial fibrillation or prolonged QT interval.
6. 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.
7. Subjects with a known latex allergy.
8. 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.

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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25 participants in 3 patient groups

Verbal Pain Score at 10 Minutes

Other group

Description:

Two 30 minute infusions of oxytocin, 10 IU, will be administered. The second infusion will be given 30 minutes after the completion of the first infusion. In this arm the first primary outcome measure (verbal pain report at the end of 5 minutes of skin heating) is obtained at 10 minutes after starting the intervention, then every 15 minutes until 115 minutes and at 180 minutes after starting the intervention. The primary outcome is also measured on separate study visits 24 hours and between 5-7 days after starting the first oxytocin infusion.

Treatment:

Drug: Oxytocin

Verbal Pain Score at 15 Minutes

Other group

Description:

Two 30 minute infusions of oxytocin, 10 IU, will be administered. The second infusion will be given 30 minutes after the completion of the first infusion. In this arm the first primary outcome measure (verbal pain report at the end of 5 minutes of skin heating) is obtained at 15 minutes after starting the intervention, then every 15 minutes until 120 minutes and at 180 minutes after starting the intervention. The primary outcome is also measured on separate study visits 24 hours and between 5-7 days after starting the first oxytocin infusion.

Treatment:

Drug: Oxytocin

Verbal Pain Score at 20 Minutes

Other group

Description:

Two 30 minute infusions of oxytocin, 10 IU, will be administered. The second infusion will be given 30 minutes after the completion of the first infusion. In this arm the first primary outcome measure (verbal pain report at the end of 5 minutes of skin heating) is obtained at 20 minutes after starting the intervention, then every 15 minutes until 125 minutes and at 180 minutes after starting the intervention. The primary outcome is also measured on separate study visits 24 hours and between 5-7 days after starting the first oxytocin infusion.

Treatment:

Drug: Oxytocin