Buprenorphine initiation strategies for opioid use disorder and pain management: A systematic review.

Buprenorphine possesses many unique attributes that make it a practical agent for adults and adolescents with opioid use disorder (OUD) and/or acute or chronic pain. Sublingual buprenorphine has been the standard of care for treating OUD, but its use in pain management is not as clearly defined. Current practice guidelines recommend a period of mild-to-moderate withdrawal from opioids before transitioning to buprenorphine due to its ability to displace full agonists from the µ-opioid receptor. However, this strategy can lead to negative physical and psychological outcomes for patients. Novel initiation strategies suggest that concomitant administration of small doses of buprenorphine with opioids can avoid the unwanted withdrawal associated with buprenorphine initiation. We aim to systematically review the buprenorphine initiation strategies that have emerged in the last decade. Embase, PubMed, and Cochrane Databases were searched for relevant literature. Studies were included if they were published in the English language and described the transition to buprenorphine from opioids. Data were collected from each study and synthesized using descriptive statistics. This review included 7 observational studies, 1 feasibility study, and 39 case reports/series which included 924 patients. The strategies utilized between the literature included traditional initiation (47.9%), microdosing with various buprenorphine formulations (16%), and miscellaneous methods (36.1%). Traditional initiation and microdosing initiation were compared in the data synthesis and analysis; miscellaneous methods were omitted given the high variability between methods. Overall, 95.6% of patients in the traditional initiation group and 96% of patients in the microdosing group successfully rotated to sublingual buprenorphine. Initiation regimens can vary widely depending on patient-specific factors and buprenorphine formulation. A variety of buprenorphine transition strategies are published in the literature, many of which were effective for patients with OUD, pain, or both.

An Electronic Aerosol Delivery System for Functional Magnetic Resonance Imaging.

BACKGROUND: Public health concerns over the addictive potential of electronic cigarettes (e-cigs) have heightened in recent years. Brain function during e-cig use could provide an objective measure of the addictive potential of new vaping products to facilitate research; however, there are limited methods for delivering e-cig aerosols during functional magnetic resonance imaging (fMRI). The current study describes the development and feasibility testing of a prototype to deliver up to four different e-cig aerosols during fMRI. METHODS: Standardized methods were used to test the devices' air flow variability, nicotine yield, and free radical production. MRI scans were run with and without the device present to assess its safety and effects on MRI data quality. Five daily smokers were recruited to assess plasma nicotine absorption from e-liquids containing nicotine concentrations of 8, 11, 16, 24, and 36 mg/ml. Feedback was collected from participants through a semi-structured interview and computerized questionnaire to assess comfort and subjective experiences of inhaling aerosol from the device. RESULTS: Nicotine yield captured from the aerosol produced by the device was highly correlated with the nicotine concentration of the e-liquids used (R2 = 0.965). Nicotine yield was reduced by a mean of 48% and free radical production by 17% after traveling through the device. The e-liquid containing the highest nicotine concentration tested (36 mg/ml) resulted in the highest plasma nicotine boost (6.6 ng/ml). Overall, participants reported that the device was comfortable to use and inhaling the e-cig aerosols was tolerable. The device was determined to be safe for use during fMRI and had insignificant effects on scan quality. CONCLUSIONS: With the current project, we were able to design a working prototype that safely and effectively delivers e-cig aerosols during fMRI. The device has the potential to be used to assess brain activation during e-cig use and to compare brain reactivity to varying flavors, nicotine concentrations, and other e-cig characteristics.