Study on the Development of Opioid Induced Hyperalgesia (OIH) After Exposure to Alfentanil

Johns Hopkins University22 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Enrollment

Conditions

Hyperalgesia

Interventions

AlfentanilDRUG

15 mcg/kg IM

DiphenhydramineDRUG

25 mg IM

Eligibility

Sex: MALEMin age: 18 YearsMax age: 55 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Locations (1)

Behavioral Pharmacology Research Unit

Baltimore, Maryland, United States

Outcomes

Primary Outcomes

Pain Tolerance

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.

Time frame: 8 sessions over 4-6 weeks

Secondary Outcomes

Pain Threshold

The amount of time (in seconds) before the participant first verbally reports feeling pain after placing hand in 4 degree Celsius circulating water bath at the 30 minute time point. Truncated at 300 seconds for safety purposes.

Time frame: 8 sessions over 4-6 weeks

Data from ClinicalTrials.gov

This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.