Willingness to take buprenorphine/naloxone among people who use opioids in Vancouver, Canada.

OBJECTIVES: Opioid agonist therapy is the cornerstone of treatment of opioid use disorder. In Canada, buprenorphine/naloxone has recently been adopted as the first line agonist therapy given its comparable effectiveness to methadone and superior safety profile. This study examines factors associated with willingness to take buprenorphine/naloxone among opioid users. METHODS: Data were derived from two prospective cohorts of high-risk individuals who use drugs in Vancouver, Canada. Multivariable logistic regression analyses were used to determine factors associated with willingness to use buprenorphine/naloxone among people who use opioids and were not currently accessing this treatment option. Participants who were unwilling to use buprenorphine/naloxone were invited to provide reason(s) and their responses were examined in a sub-analysis. RESULTS: Between December 2014 and May 2018, 1103 participants were interviewed. Overall, 194 (17.6%) respondents indicated that they would be willing to take buprenorphine/naloxone. Variables independently associated with willingness were previous buprenorphine/naloxone treatment (adjusted odds ratio [AOR] = 2.04), having ever used methadone treatment (AOR = 1.87), and age (AOR = 0.98, per year older) (all p < 0.05). Satisfaction with current agonist therapy (25.4%), not knowing what buprenorphine/naloxone is (25.1%), and wanting more information about buprenorphine/naloxone (15.1%) were the most commonly cited reasons for unwillingness. A low rate of willingness to use buprenorphine/naloxone (15.1%) was also observed among the sub-set of participants not using methadone. CONCLUSIONS: While an overall low level of willingness to take buprenorphine/naloxone was observed, this appeared to be largely driven by satisfaction with other agonists and a low prevalence of community knowledge about buprenorphine/naloxone.

Activation of Carbon Dioxide by Silyl Triflate-Based Frustrated Lewis Pairs.

Silyl triflates of the form R4-n Si(OTf)n (n=1, 2; OTf=OSO3 CF3 ) are shown to activate carbon dioxide when paired with bulky alkyl-substituted Group 15 bases. Combinations of silyl triflates and 2,2,6,6-tetramethylpiperidine react with CO2 to afford silyl carbamates via a frustrated Lewis pair-type mechanism. With trialkylphosphines, the silyl triflates R3 Si(OTf) reversibly bind CO2 affording [R'3 P(CO2 )SiR3 ][OTf] whereas when Ph2 Si(OTf)2 is used one or two molecules of CO2 can be sequestered. The latter bis-CO2 product is favoured at low temperatures and by excess phosphine.