This is a pilot study to collect preliminary data to support a grant application. The goal of the study is to evaluate whether the Food and Drug Administration (FDA)-approved and generically-available medication buspirone reduces symptoms of opioid withdrawal among patients undergoing a clinically-indicated and supervised taper from their opioid pain medications. This is premised on strong preclinical scientific support but has not yet be well-examined in humans.

Buspirone (Buspar) has shown initial efficacy in reducing symptoms of opioid withdrawal in animal studies and in human patients undergoing a methadone taper. Buspirone may have pharmacologic activity in specific neurotransmitter systems that preclinical evidence suggests may be implicated in the manifestation of opioid withdrawal symptoms. Administration of buspirone during an opioid taper may improve outcomes relative to placebo. The goal of this study is to collect preliminary feasibility and efficacy data from a sample of patients undergoing clinically-indicated opioid tapering. Participant enrollment will occur at the beginning of their residential stay on the Pain Treatment Unit at Johns Hopkins Hospital. Participants will be randomly assigned to receive buspirone (15 milligrams, three times daily, for daily dose of 45 milligrams) or placebo. Daily assessments for withdrawal and requests for additional symptomatic medications will be evaluated as evidence of initial efficacy. Feasibility measures include willingness to participate and study retention.

Inclusion Criteria:

• Be at least 18 years old
• Be undergoing taper of prescribed opioid pain medications at the study site

Exclusion Criteria:

• Being pregnant or breastfeeding
• Past 7-day use of grapefruit juice or other strong Cytochrome (CYP) P450 inhibitors or inducers
• Have medical or psychiatric condition that is contraindicated with buspirone administration
• Current suicidality as assessed by clinic staff or the Columbia Suicide Severity Rating Scale

Double-blind placebo controlled study. Patients are randomized to receive either active buspirone or placebo, each of which is over-encapsulated to support blinding.