Prescription Medication Interactions

Sharon Walsh

Status and phase: Completed; Phase 1

Conditions: Opioid Use; Sedative Use

Treatments: Drug: Opioid Agonist; Drug: Sedatives

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT04315181

R01DA016718 (U.S. NIH Grant/Contract)

46591

Details and patient eligibility

About

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.

Full 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.

Enrollment: 11 patients

Sex: All

Ages: 18 to 55 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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11 participants in 9 patient groups, including a placebo group

Placebo / Placebo

Placebo Comparator group

Description:

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.

Treatment:

Drug: Sedatives

Drug: Opioid Agonist

Placebo / Oxycodone 20mg

Experimental group

Description:

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.

Treatment:

Drug: Sedatives

Drug: Opioid Agonist

Placebo / Oxycodone 40mg

Experimental group

Description:

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.

Treatment:

Drug: Sedatives

Drug: Opioid Agonist

Gabapentin 600mg / Placebo

Experimental group

Description:

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.

Treatment:

Drug: Sedatives

Drug: Opioid Agonist

Gabapentin 1200mg / Placebo

Experimental group

Description:

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.

Treatment:

Drug: Sedatives

Drug: Opioid Agonist

Gabapentin 600mg / Oxycodone 20mg

Experimental group

Description:

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.

Treatment:

Drug: Sedatives

Drug: Opioid Agonist

Gabapentin 1200mg / Oxycodone 20mg

Experimental group

Description:

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.

Treatment:

Drug: Sedatives

Drug: Opioid Agonist

Gabapentin 600mg / Oxycodone 40mg

Experimental group

Description:

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.

Treatment:

Drug: Sedatives

Drug: Opioid Agonist

Gabapentin 1200mg / Oxycodone 40mg

Experimental group

Description:

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.

Treatment:

Drug: Sedatives

Drug: Opioid Agonist