A Pilot Study of Prolonged, Intermittent Exposure to Alfentanil on Opioid-Induced Hyperalgesia in Healthy Volunteers
Overview
- Phase
- Not Applicable
- Intervention
- Alfentanil
- Conditions
- Hyperalgesia
- Sponsor
- Johns Hopkins University
- Enrollment
- 22
- Locations
- 1
- Primary Endpoint
- Pain Tolerance
- Status
- Completed
- Last Updated
- 8 years ago
Overview
Brief Summary
The purpose of this study was to follow a person's response to experimental pain after multiple consecutive exposures to alfentanil or diphenhydramine to see if the person can tolerate the pain more, less, or the same at the end of the study.
Detailed Description
This project investigates the phenomenon of opioid-induced hyperalgesia (OIH). Opioid analgesics, in addition to their therapeutic anti-nociceptive effects, under some conditions produce pro-nociceptive effects. This phenomenon of pain or pain sensitivity being increased by prior opioid administration is called opioid-induced hyperalgesia. It is thought to be relevant both to pain management complications and to complications of opioid dependence and its treatment. This study investigated the time-course of opioid-induced hyperalgesia development in healthy normal volunteers (N=12 completers), using a series of acute alfentanil administrations (15 mg/kg mg intramuscular (IM) per day) spaced at 3-4 day intervals, with testing for pain tolerance using the cold pressor test (CPT), and mechanical quantitative sensory testing (MQST) each administered repeatedly over time within each testing day. The goal was to determine the time course of OIH development following acute opioid administration, and to assess whether this changes over repeated acute opioid administrations.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Age 18-55
- •No active medical conditions
- •BMI between 20-30
- •Able and willing to perform/tolerate pain procedures
- •Able to communicate in English
Exclusion Criteria
- •Lifetime substance use disorder, except for alcohol abuse/dependence in remission
- •Use of opiates in last 3 months
- •Ongoing marijuana use
- •Acute or chronic pain
- •Neurologic or psychiatric condition known to influence cold pressor testing (peripheral neuropathy, major depression, or schizophrenia)
- •Current use of prescribed or over the counter pain medications
- •Previous adverse reaction to opiate medications or diphenhydramine
- •Use of tobacco or caffeine on study days
Arms & Interventions
Alfentanil
Subjects received a series of acute alfentanil administrations each session (15 mcg/kg IM per session), with sessions spaced at 3-4 day intervals.
Intervention: Alfentanil
Diphenhydramine
Subjects received a series of acute diphenhydramine administrations each session (25 mg IM per session), with sessions spaced at 3-4 day intervals.
Intervention: Diphenhydramine
Outcomes
Primary Outcomes
Pain Tolerance
Time Frame: 8 sessions over 4-6 weeks
The participant places their hand in a water bath kept at 4 degrees Celsius (cold pressor test). They then continue to hold the hand in the water bath until they can no longer tolerate the pain (pain tolerance) or until the end of the testing (truncated at 300 seconds for safety purposes). Reported as the mean (time to hand removal in seconds) at the 30 minute time point.
Secondary Outcomes
- Pain Threshold(8 sessions over 4-6 weeks)