Ketamine-assisted buprenorphine initiation: a pilot case series

Many people with opioid use disorder who stand to benefit from buprenorphine treatment are unwilling to initiate it due to experience with or fear of both spontaneous and buprenorphine-precipitated opioid withdrawal (BPOW). An effective means of minimizing withdrawal symptoms would reduce patient apprehensiveness, lowering the barrier to buprenorphine initiation. Ketamine, approved by the FDA as a dissociative anesthetic, completely resolved BPOW in case reports when infused at a sub-anesthetic dose range in which dissociative symptoms are common. However, most patients attempt buprenorphine initiation in the outpatient setting where altered mental status is undesirable. We explored the potential of short-term use of ketamine, self-administered sublingually at a lower, sub-dissociative dose to assist ambulatory patients undergoing transition to buprenorphine from fentanyl and methadone.