Combination non-medical use of gabapentin and medications for opioid use disorder: A qualitative study

Background:  Despite the risks associated with the concurrent use of gabapentin and opioids (e.g., respiratory depression and overdose), in the United States, alongside increasing gabapentin prescriptions there are increasing reports of non-medical use of gabapentin and opioids in combination.  This concurrent non-medical use of opioid/gabapentin also includes opioid agonist medications (OAMs) buprenorphine and methadone, yet, little is known about individuals engaging in this practice and their motivations for doing so.  The aim of this ongoing qualitative study is to examine non-medical use of gabapentin in combination with OAMs to inform treatment and prescribing practices.  
Methods:  In-depth interviews are conducted with individuals in treatment for opioid use disorder.  Eligible participants are 18 years of age or older and report:  1) report past year non-medical use of gabapentin; 2) past 90 day non-medical use of prescription opioids and/or use of illicit opioids; and 3) combination non-medical use of gabapentin and OAMs.  To date, 14 interviews out of 30 have been completed.  Interviews are being coded using descriptive and in vivo coding schemes and themed for analysis using Atlas.ti software.   
Results:  All participants described engaging in non-medical use of gabapentin for recreational purposes, including to come down from another drug (n=4); to relax (n=4); or to get high or potentiate the effect of an opioid, including OAMs (n=5).  An additional 9 participants described therapeutic motivations for non-medical gabapentin use, including to self-treat addiction and mitigate opioid craving and withdrawal (n=4); to self-treat mental health problems like anxiety or mood disorders (n=4); and to self-treat physical pain (n=1). Individuals with therapeutic motivations reported more mean days of gabapentin non-medical use (35.00 vs. 23.64) and greater mean gabapentin liking scores (74.44 vs. 66.28; range 0-100) compared to those with only recreational motivations.  In addition, individuals with therapeutic motivations reported greater frequency of treatment occurrences (8.55 vs. 6.71) and overdose/drug emergency occurrences (6.44 vs. 4.35) compared to recreational participants.  
Conclusions:  Although these results are preliminary and data collection is ongoing, they represent the first in-depth reports of experiences of individuals in treatment who engage in non-medical use of gabapentin and OAMs in combination.  Participants’ descriptions suggest that in addition to OAMs, gabapentin serves to further treat OUD symptoms as well as co-morbid health problems, and participants appear to like gabapentin more when used for self-therapeutic motivations.   Data suggest these individuals may need additional health services alongside OUD treatment which could mitigate non-medical use of gabapentin in combination with OAMs and reduce risk for adverse consequences.