Neuropathic Pain
Conditions
Keywords
chronic pain, neuropathic pain
Brief summary
The purpose of the study is to determine the effect of oxytocin given into the spinal fluid on pain and areas and intensity of hyperalgesia and allodynia in patients with chronic neuropathic pain.
Detailed description
Rationale: The investigators anticipate that oxytocin will be effective after spinal injection in humans to acutely relieve chronic neuropathic pain. Objectives: Determine the effect of intrathecal oxytocin on pain and areas and intensity of hyperalgesia and allodynia in patients with chronic neuropathic pain. Interventions: A computer generated randomization will be used to determine the group for each subject. Subjects will be randomized to receive an intrathecal injection of saline (placebo) or oxytocin.
Interventions
DRUGoxytocin 100 micrograms
oxytocin 100 micrograms administered intrathecally (IT)
DRUGNormal Saline (preservative free)
Normal Saline (preservative free) administered intrathecally (IT)
Sponsors
Wake Forest University Health Sciences
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Weight \< or equal to 240 pounds * Neuropathic pain for \> 6 months: with primary pain area below the umbilicus
Exclusion criteria
* Hypersensitivity, allergy, or significant reaction to any ingredient of the study drug or lidocaine * 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 * Pregnancy * spinal cord stimulators, chronic intrathecal drug therapy, or oral opioid treatment for \> 3 months at a current dose of \> 100 milligram (mg) morphine per day or equivalent.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Spontaneous Pain From Their Neuropathic Pain Disease | 240 minutes post injection | Pain will be measured by visual analog scale, a 10 cm line with 0/no pain on the left end and 10/pain as worse as can be on the right end. The subject places a mark on the line and the score is determined by the distance in cm from the no pain end. |
Countries
United States
Participant flow
Pre-assignment details
Two subjects were not randomized, one because of an abnormal electrocardiogram and the other for lack of spontaneous neuropathic pain at rest. Six subjects were randomized and received the first intrathecal injection. Participant flow section includes randomized subjects only.
Participants by arm
| Arm | Count |
|---|---|
| Oxytocin, Then Placebo The subject first received oxytocin 100 micrograms administered intrathecally (IT). After at least one week, they received normal saline placebo IT.
oxytocin 100 micrograms: oxytocin 100 micrograms administered intrathecally (IT)
Normal Saline (preservative free): Normal Saline (preservative free) administered intrathecally (IT) | 3 |
| Placebo, Then Oxytocin The subject first received normal saline placebo intrathecally (IT). After at least one week, they then received oxytocin 100 micrograms administered IT.
oxytocin 100 micrograms: oxytocin 100 micrograms administered intrathecally (IT)
Normal Saline (preservative free): Normal Saline (preservative free) administered intrathecally (IT) | 3 |
| Total | 6 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| At Least One Week Between Injections | Adverse Event | 0 | 1 |
Baseline characteristics
| Characteristic | Oxytocin, Then Placebo | Placebo, Then Oxytocin | Total |
|---|---|---|---|
| Age, Continuous | 49 years | 54 years | 52 years |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants | 1 Participants | 2 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 2 Participants | 2 Participants | 4 Participants |
| Region of Enrollment United States | 3 participants | 3 participants | 6 participants |
| Sex: Female, Male Female | 1 Participants | 2 Participants | 3 Participants |
| Sex: Female, Male Male | 2 Participants | 1 Participants | 3 Participants |
| Visual Analog Scale Pain | 4.2 units on a scale | 2.6 units on a scale | 3.9 units on a scale |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 6 | 0 / 6 |
| other Total, other adverse events | 0 / 6 | 1 / 6 |
| serious Total, serious adverse events | 0 / 6 | 0 / 6 |
Outcome results
Primary
Spontaneous Pain From Their Neuropathic Pain Disease
Pain will be measured by visual analog scale, a 10 cm line with 0/no pain on the left end and 10/pain as worse as can be on the right end. The subject places a mark on the line and the score is determined by the distance in cm from the no pain end.
Time frame: 240 minutes post injection
Population: The intention to treat population was defined as individuals who were randomized and received intrathecal drug on both study days of the trial. This includes subjects who completed both injections.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oxytocin Injection | Spontaneous Pain From Their Neuropathic Pain Disease | 1.67 score on a scale | Standard Error 0.87 |
| Placebo Injection | Spontaneous Pain From Their Neuropathic Pain Disease | 2.43 score on a scale | Standard Error 0.89 |
Comparison: Null hypothesis was that there was no difference in VAS pain scale scores after intrathecal study drug injection between oxytocin and placebo. To account for repeated measures across time and drug conditions, VAS apin scale scores were analyzed using a linear mixed-effects model with random intercepts at the level of participant. Each outcome was regressed on fixed-effects for order of study day, study drug, time after injection, and drug x time interaction.p-value: <0.05Mixed Models Analysis