Prescription Medication Interactions

Purpose

This study will examine the effects of doses of opioid/placebo and doses of sedative/placebo, alone and in combination. The primary outcomes are related to pharmacodynamic measures (subjective ratings of drug liking and other abuse-related effects; physiological outcomes) to determine the interaction effects of these compounds.

Conditions

  • Opioid Use
  • Sedative Use

Eligibility

Eligible Ages
Between 18 Years and 55 Years
Eligible Sex
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  • Healthy adults, ages 18-55 - Current non-medical use of opioids and sedatives

Exclusion Criteria

  • Physical dependence on opioids, alcohol, or benzodiazepines/sedatives/hypnotics - Seeking treatment for drug use - Significant medical problems

Study Design

Phase
Phase 1
Study Type
Interventional
Allocation
Randomized
Intervention Model
Crossover Assignment
Primary Purpose
Basic Science
Masking
Double (Participant, Investigator)
Masking Description
This is a randomized, double-blind, double-dummy, placebo- controlled design

Arm Groups

ArmDescriptionAssigned Intervention
Placebo Comparator
Placebo / Placebo 		Participants will receive non-therapeutic experimental doses of gabapentin (600 and 1200 mg, p.o.), alone and in combination with oxycodone (20 and 40 mg, p.o.). The experimental sessions are designed to capture the time-action curves for the test drugs (Tmax for gabapentin ≈ 2.5 hr; oxycodone ≈ 1.5 hr). Therefore, oxycodone will be administered 1 hr after gabapentin to align peak responses.
  • Drug: Opioid Agonist
    Abuse liability evaluation.
  • Drug: Sedatives
    Abuse liability evaluation.
Experimental
Placebo / Oxycodone 20mg 		Participants will receive non-therapeutic experimental doses of gabapentin (600 and 1200 mg, p.o.), alone and in combination with oxycodone (20 and 40 mg, p.o.). The experimental sessions are designed to capture the time-action curves for the test drugs (Tmax for gabapentin ≈ 2.5 hr; oxycodone ≈ 1.5 hr). Therefore, oxycodone will be administered 1 hr after gabapentin to align peak responses.
  • Drug: Opioid Agonist
    Abuse liability evaluation.
  • Drug: Sedatives
    Abuse liability evaluation.
Experimental
Placebo / Oxycodone 40mg 		Participants will receive non-therapeutic experimental doses of gabapentin (600 and 1200 mg, p.o.), alone and in combination with oxycodone (20 and 40 mg, p.o.). The experimental sessions are designed to capture the time-action curves for the test drugs (Tmax for gabapentin ≈ 2.5 hr; oxycodone ≈ 1.5 hr). Therefore, oxycodone will be administered 1 hr after gabapentin to align peak responses.
  • Drug: Opioid Agonist
    Abuse liability evaluation.
  • Drug: Sedatives
    Abuse liability evaluation.
Experimental
Gabapentin 600mg / Placebo 		Participants will receive non-therapeutic experimental doses of gabapentin (600 and 1200 mg, p.o.), alone and in combination with oxycodone (20 and 40 mg, p.o.). The experimental sessions are designed to capture the time-action curves for the test drugs (Tmax for gabapentin ≈ 2.5 hr; oxycodone ≈ 1.5 hr). Therefore, oxycodone will be administered 1 hr after gabapentin to align peak responses.
  • Drug: Opioid Agonist
    Abuse liability evaluation.
  • Drug: Sedatives
    Abuse liability evaluation.
Experimental
Gabapentin 1200mg / Placebo 		Participants will receive non-therapeutic experimental doses of gabapentin (600 and 1200 mg, p.o.), alone and in combination with oxycodone (20 and 40 mg, p.o.). The experimental sessions are designed to capture the time-action curves for the test drugs (Tmax for gabapentin ≈ 2.5 hr; oxycodone ≈ 1.5 hr). Therefore, oxycodone will be administered 1 hr after gabapentin to align peak responses.
  • Drug: Opioid Agonist
    Abuse liability evaluation.
  • Drug: Sedatives
    Abuse liability evaluation.
Experimental
Gabapentin 600mg / Oxycodone 20mg 		Participants will receive non-therapeutic experimental doses of gabapentin (600 and 1200 mg, p.o.), alone and in combination with oxycodone (20 and 40 mg, p.o.). The experimental sessions are designed to capture the time-action curves for the test drugs (Tmax for gabapentin ≈ 2.5 hr; oxycodone ≈ 1.5 hr). Therefore, oxycodone will be administered 1 hr after gabapentin to align peak responses.
  • Drug: Opioid Agonist
    Abuse liability evaluation.
  • Drug: Sedatives
    Abuse liability evaluation.
Experimental
Gabapentin 1200mg / Oxycodone 20mg 		Participants will receive non-therapeutic experimental doses of gabapentin (600 and 1200 mg, p.o.), alone and in combination with oxycodone (20 and 40 mg, p.o.). The experimental sessions are designed to capture the time-action curves for the test drugs (Tmax for gabapentin ≈ 2.5 hr; oxycodone ≈ 1.5 hr). Therefore, oxycodone will be administered 1 hr after gabapentin to align peak responses.
  • Drug: Opioid Agonist
    Abuse liability evaluation.
  • Drug: Sedatives
    Abuse liability evaluation.
Experimental
Gabapentin 600mg / Oxycodone 40mg 		Participants will receive non-therapeutic experimental doses of gabapentin (600 and 1200 mg, p.o.), alone and in combination with oxycodone (20 and 40 mg, p.o.). The experimental sessions are designed to capture the time-action curves for the test drugs (Tmax for gabapentin ≈ 2.5 hr; oxycodone ≈ 1.5 hr). Therefore, oxycodone will be administered 1 hr after gabapentin to align peak responses.
  • Drug: Opioid Agonist
    Abuse liability evaluation.
  • Drug: Sedatives
    Abuse liability evaluation.
Experimental
Gabapentin 1200mg / Oxycodone 40mg 		Participants will receive non-therapeutic experimental doses of gabapentin (600 and 1200 mg, p.o.), alone and in combination with oxycodone (20 and 40 mg, p.o.). The experimental sessions are designed to capture the time-action curves for the test drugs (Tmax for gabapentin ≈ 2.5 hr; oxycodone ≈ 1.5 hr). Therefore, oxycodone will be administered 1 hr after gabapentin to align peak responses.
  • Drug: Opioid Agonist
    Abuse liability evaluation.
  • Drug: Sedatives
    Abuse liability evaluation.

Recruiting Locations

More Details

NCT ID
NCT04315181
Status
Completed
Sponsor
Sharon Walsh

Detailed Description

Gabapentin and oxycodone are commonly used in combination for the treatment of chronic pain. Gabapentin is now widely misused/abused with studies indicating that gabapentin abuse is especially common among individuals with opioid misuse. The nature of gabapentin's abuse-related effects have been described in case reports and online as sedative-like and opioid-like, with descriptive reports including sedation, euphoria, talkativeness and increased energy. Despite their widespread co-administration both for licit and illicit purposes, no controlled psychopharmacological studies to our knowledge have directly examined the effects of oxycodone (or another opioid agonist) and gabapentin in combination. This study's objective is to characterize the subjective effect profile of gabapentin, examine the interaction between gabapentin and oxycodone, and assess the acute analgesic response to gabapentin and oxycodone, alone and in combination, across a range of doses for each drug.