Cessation of funding period prior to completion, due to slow recruitment during the pandemic

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.

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.

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.

6 months after second intrathecal injection, up to 6.5 months

Peripheral oxyhemoglobin saturation, blood pressure, and heart rate were measured non invasively and recorded before and 15, 30, 60, 120, 180, 240, minutes after intrathecal injection. The electrocardiogram was continuously monitored. A neurologic examination was performed at intervals until 24 hours after injection. Serum sodium was assayed 24 hr after injection. Subjects were called 2, 3, 4, 5, 7 days, then weekly until one month and then at 6 months after the second intrathecal injection.

This study was terminated early due to slow recruitment and lack of funding.