Buprenorphine: a primer for emergency physicians

Efficacy of opioids for traumatic pain in the emergency department: a systematic review and Bayesian network meta-analysis

Aim: To systematically assess and rank the efficacy of opioid medications for traumatic pain in the emergency department in terms of pain relief, adverse events and rescue analgesia. Methods: Four databases were systematically searched until 26 September 2022: PubMed, Embase, Cochrane Library, and Web of Science. Outcomes were pain relief, adverse events (dizziness, hypotension, pruritus, sedation), and rescue analgesia. For each outcome, network plots were drawn to exhibit direct and indirect comparisons, and rank probabilities were utilized to rank the efficacy of different opioids. Results: Twenty studies of 3,040 patients were eligible for this network meta-analysis. According to the rank probabilities, the top three analgesic medications for pain relief may be sufentanil (78.29% probability of ranking first), buprenorphine (48.54% probability of ranking second) and fentanyl (53.25% probability of ranking third); buprenorphine (31.20%), fentanyl (20.14%) and sufentanil (21.55%) were least likely to cause dizziness; the top three analgesic medications which were least likely to cause hypotension were buprenorphine (81.64%), morphine (45.02%) and sufentanil (17.27%); butorphanol (40.56%), morphine (41.11%) and fentanyl (14.63%) were least likely to cause pruritus; the top three medications which were least likely to cause sedation were hydrocodone + acetaminophen (97.92%), morphine (61.85%) and butorphanol (55.24%); patients who received oxycodone (83.64%), butorphanol (38.31%) and fentanyl (25.91%) were least likely to need rescue analgesia in sequence. Conclusion: Sufentanil, buprenorphine and fentanyl may be superior to other opioid medications in terms of pain relief and the incidence of dizziness, hypotension and pruritus, which might be selected as opioid analgesics for traumatic pain in the emergency setting.

Opioid use disorder in pregnancy: leveraging provider perceptions to inform comprehensive treatment

BACKGROUND

Medications for opioid use disorder (MOUD) are recommended with adjuvant behavioral therapies, counseling, and other services for comprehensive treatment of maternal opioid use disorder. Inadequate access to treatment, lack of prescribing providers and complex delivery models are among known barriers to care. Multi-disciplinary provider input can be leveraged to comprehend factors that facilitate or inhibit treatment. The objective of this study is to explore provider perceptions of MOUD and factors critical to comprehensive treatment delivery to improve the care of pregnant women with opioid use disorder.

METHODS

A qualitative research approach was used to gather data from individual provider and group semi-structured interviews. Providers (n = 12) responded to questions in several domains related to perceptions of MOUD, treatment delivery, access to resources, and challenges/barriers. Data were collected, transcribed, coded (by consensus) and emerging themes were analyzed using grounded theory methodology.

RESULTS

Emerging themes revealed persistent gaps in treatment and challenges in provider, health systems and patient factors. Providers perceived MOUD to be a "lifeline" to women.

CONCLUSIONS

Inconsistencies in treatment provision, access and uptake can be improved by leveraging provider perceptions, direct experiences and recommendations for an integrated team-based, patient-centered approach to guide the care of pregnant women with opioid use disorder.

Opioid agonist treatment and risk of mortality during opioid overdose public health emergency: population based retrospective cohort study

OBJECTIVE

To compare the risk of mortality among people with opioid use disorder on and off opioid agonist treatment (OAT) in a setting with a high prevalence of illicitly manufactured fentanyl and other potent synthetic opioids in the illicit drug supply.

DESIGN

Population based retrospective cohort study.

SETTING

Individual level linkage of five health administrative datasets capturing drug dispensations, hospital admissions, physician billing records, ambulatory care reports, and deaths in British Columbia, Canada.

PARTICIPANTS

55 347 people with opioid use disorder who received OAT between 1 January 1996 and 30 September 2018.

MAIN OUTCOME MEASURES

All cause and cause specific crude mortality rates (per 1000 person years) to determine absolute risk of mortality and all cause age and sex standardised mortality ratios to determine relative risk of mortality compared with the general population. Mortality risk was calculated according to treatment status (on OAT, off OAT), time since starting and stopping treatment (1, 2, 3-4, 5-12, >12 weeks), and medication type (methadone, buprenorphine/naloxone). Adjusted risk ratios compared the relative risk of mortality on and off OAT over time as fentanyl became more prevalent in the illicit drug supply.

RESULTS

7030 (12.7%) of 55 347 OAT recipients died during follow-up. The all cause standardised mortality ratio was substantially lower on OAT (4.6, 95% confidence interval 4.4 to 4.8) than off OAT (9.7, 9.5 to 10.0). In a period of increasing prevalence of fentanyl, the relative risk of mortality off OAT was 2.1 (95% confidence interval 1.8 to 2.4) times higher than on OAT before the introduction of fentanyl, increasing to 3.4 (2.8 to 4.3) at the end of the study period (65% increase in relative risk).

CONCLUSIONS

Retention on OAT is associated with substantial reductions in the risk of mortality for people with opioid use disorder. The protective effect of OAT on mortality increased as fentanyl and other synthetic opioids became common in the illicit drug supply, whereas the risk of mortality remained high off OAT. As fentanyl becomes more widespread globally, these findings highlight the importance of interventions that improve retention on opioid agonist treatment and prevent recipients from stopping treatment.

MySafeRx: a mobile technology platform integrating motivational coaching, adherence monitoring, and electronic pill dispensing for enhancing buprenorphine/naloxone adherence during opioid use disorder treatment: a pilot study

Background

While buprenorphine/naloxone (B/N) is approved for opioid use disorder treatment, effective delivery of B/N comes with significant challenges. Most notably, many patients do not take medication daily as prescribed; this non-adherence worsens treatment outcomes, increases healthcare costs, and leads to persistent worries of diversion among providers and policymakers. The present study examines the feasibility, usability, and acceptability of MySafeRx—a mobile technology platform integrating motivational coaching, adherence monitoring, and electronic pill dispensing designed to address the challenges of office-based opioid treatment (OBOT) with B/N.

Methods

The MySafeRx platform integrates electronic pill dispensers, text-messaging, and videoconferencing to provide supervised self-administration of medication and daily motivational coaching through an Android app interface. High-risk early adults (18–39 years old) who were enrolled in OBOT with B/N and had documented illicit opioid use in the past month during opioid agonist therapy (n = 12) participated in a 28-day single-arm observational study of the MySafeRx platform in addition to standard care.

Results

Two-thirds of participants who completed the study achieved an average of > 5 days per week of supervised B/N self-administration. Visual confirmation of medication adherence was demonstrated for an average of 72% of study days among all participants. All participants achieved platform technical proficiency within 60 min, reporting good levels of usability and acceptability. Illicit opioid abstinence rates confirmed by urine toxicology increased by 53% during MySafeRx but fell 43% within 3 weeks post-intervention.

Conclusion

The MySafeRx medication adherence and remote coaching mobile platform is acceptable and can be feasibly implemented in real-world opioid use disorder treatment settings during high-risk periods (i.e., initial stabilization, after illicit opioid lapse), resulting in reduced illicit opioid use; however, the effect did not last after intervention completion, suggesting longer duration or extended taper of program may be needed.

ClinicalTrials.Gov NCT02942199 10/24/16 https://clinicaltrials.gov/ct2/show/NCT02942199

Electronic supplementary material

The online version of this article (10.1186/s13722-018-0122-4) contains supplementary material, which is available to authorized users.

To Stop or Not, That Is the Question: Acute Pain Management for the Patient on Chronic Buprenorphine

Perioperative pain management suggestions for patients taking buprenorphine and presenting for elective and urgent/emergent surgery have been developed and are described here.

Opiate Drugs with Abuse Liability Hijack the Endogenous Opioid System to Disrupt Neuronal and Glial Maturation in the Central Nervous System

The endogenous opioid system, comprised of multiple opioid neuropeptide and receptor gene families, is highly expressed by developing neural cells and can significantly influence neuronal and glial maturation. In many central nervous system (CNS) regions, the expression of opioid peptides and receptors occurs only transiently during development, effectively disappearing with subsequent maturation only to reemerge under pathologic conditions, such as with inflammation or injury. Opiate drugs with abuse liability act to modify growth and development by mimicking the actions of endogenous opioids. Although typically mediated by μ-opioid receptors, opiate drugs can also act through δ- and κ-opioid receptors to modulate growth in a cell-type, region-specific, and developmentally regulated manner. Opioids act as biological response modifiers and their actions are highly contextual, plastic, modifiable, and influenced by other physiological processes or pathophysiological conditions, such as neuro-acquired immunodeficiency syndrome. To date, most studies have considered the acute effects of opiates on cellular maturation. For example, activating opioid receptors typically results in acute growth inhibition in both neurons and glia. However, with sustained opioid exposure, compensatory factors become operative, a concept that has been largely overlooked during CNS maturation. Accordingly, this article surveys prior studies on the effects of opiates on CNS maturation, and also suggests new directions for future research in this area. Identifying the cellular and molecular mechanisms underlying the adaptive responses to chronic opiate exposure (e.g., tolerance) during maturation is crucial toward understanding the consequences of perinatal opiate exposure on the CNS.

The New Kid on the Block--Incorporating Buprenorphine into a Medical Toxicology Practice

Buprenorphine represents a safe and effective therapy for treating opioid dependence, alleviating craving and withdrawal symptoms in opioid-dependent patients. Buprenorphine has a "blocking" effect against the action of other opioids at the mu-receptor, preventing not only opioid-induced euphoria, but CNS and respiratory depressant effects as well. Buprenorphine was approved for the treatment of opioid dependence in 2002 after the passage of Drug Abuse Treatment Act 2000 (DATA 2000) which allowed clinicians to treat opioid-dependent patients with specifically named opioid agonist therapies in an office setting. Buprenorphine programs reduce the prevalence of HIV and hepatitis C and reduce criminal behaviors associated with illicit drug use. Patients stabilized on buprenorphine have increased employment, enhanced engagement with social services, and better overall health and well-being.

Opiate addiction therapies and HIV-1 Tat: interactive effects on glial [Ca²⁺]i, oxyradical and neuroinflammatory chemokine production and correlative neurotoxicity

Few preclinical studies have compared the relative therapeutic efficacy of medications used to treat opiate addiction in relation to neuroAIDS. Here we compare the ability of methadone and buprenorphine, and the prototypic opiate morphine, to potentiate the neurotoxic and proinflammatory ([Ca²⁺]i, ROS, H2O2, chemokines) effects of HIV-1 Tat in neuronal and/or mixed-glial co-cultures. Repeated observations of neurons during 48 h exposure to combinations of Tat, equimolar concentrations (500 nM) of morphine, methadone, or buprenorphine exacerbated neurotoxicity significantly above levels seen with Tat alone. Buprenorphine alone displayed marked neurotoxicity at 500 nM, prompting additional studies of its neurotoxic effects at 5 nM and 50 nM concentrations ± Tat. In combination with Tat, buprenorphine displayed paradoxical, concentration-dependent, neurotoxic and neuroprotective actions. Buprenorphine neurotoxicity coincided with marked elevations in [Ca²⁺]i, but not increases in glial ROS or chemokine release. Tat by itself elevated the production of CCL5/RANTES, CCL4/MIP-1β, and CCL2/MCP-1. Methadone and buprenorphine alone had no effect, but methadone interacted with Tat to further increase production of CCL5/RANTES. In combination with Tat, all drugs significantly increased glial [Ca²⁺]i, but ROS was only significantly increased by co-exposure with morphine. Taken together, the increases in glial [Ca²⁺]i, ROS, and neuroinflammatory chemokines were not especially accurate predictors of neurotoxicity. Despite similarities, opiates displayed differences in their neurotoxic and neuroinflammatory interactions with Tat. Buprenorphine, in particular, was partially neuroprotective at a low concentration, which may result from its unique pharmacological profile at multiple opioid receptors. Overall, the results reveal differences among addiction medications that may impact neuroAIDS.

Methadone and buprenorphine-naloxone are effective in reducing illicit buprenorphine and other opioid use, and reducing HIV risk behavior--outcomes of a randomized trial

AIMS

Determine the extent to which buprenorphine injectors continue treatment with buprenorphine-naloxone or methadone, and the impact of these treatments on substance use and HIV risk in the Republic of Georgia.

METHODS

Randomized controlled 12-week trial of daily-observed methadone or buprenorphine-naloxone followed by a dose taper, referral to ongoing treatment, and follow-up at week 20 at the Uranti Clinic in Tbilisi, Republic of Georgia. Eighty consenting treatment-seeking individuals (40/group) aged 25 and above who met ICD-10 criteria for opioid dependence with physiologic features and reported injecting buprenorphine 10 or more times in the past 30 days. Opioid use according to urine tests and self-reports, treatment retention, and HIV risk behavior as determined by the Risk Assessment Battery.

RESULTS

Mean age of participants was 33.7 (SD5.7), 4 were female, mean history of opioid injection use was 5.8 years (SD4.6), none were HIV+ at intake or at the 12-week assessment and 73.4% were HCV+. Sixty-eight participants (85%) completed the 12-week medication phase (33 from methadone and 35 from buprenorphine/naloxone group); 37 (46%) were in treatment at the 20-week follow-up (21 from methadone and 16 from the buprenorphine/naloxone group). In both study arms, treatment resulted in a marked reduction in unprescribed buprenorphine, other opioid use, and HIV injecting risk behavior with no clinically significant differences between the two treatment arms.

CONCLUSIONS

Daily observed methadone or buprenorphine-naloxone are effective treatments for non-medical buprenorphine and other opioid use in the Republic of Georgia and likely to be useful for preventing HIV infection.

Intravenous buprenorphine and norbuprenorphine pharmacokinetics in humans

BACKGROUND

Prescribed sublingual (SL) buprenorphine is sometimes diverted for intravenous (IV) abuse, but no human pharmacokinetic data are available following high-dose IV buprenorphine.

METHODS

Plasma was collected for 72 h after administration of placebo or 2, 4, 8, 12, or 16 mg IV buprenorphine in escalating order (single-blind, double-dummy) in 5 healthy male non-dependent opioid users. Buprenorphine and its primary active metabolite, norbuprenorphine, were quantified by liquid chromatography-tandem mass spectrometry with limits of quantitation of 0.1 μg/L.

RESULTS

Maximum buprenorphine concentrations (mean ± SE) were detected 10 min after 2, 4, 8, 12, 16 mg IV: 19.3 ± 1.0, 44.5 ± 4.8, 85.2 ± 7.7, 124.6 ± 16.6, and 137.7 ± 18.8 μg/L, respectively. Maximum norbuprenorphine concentrations occurred 10-15 min (3.7 ± 0.7 μg/L) after 16 mg IV administration.

CONCLUSIONS

Buprenorphine concentrations increased in a significantly linear dose-dependent manner up to 12 mg IV buprenorphine. Thus, previously demonstrated pharmacodynamic ceiling effects (over 2-16 mg) are not due to pharmacokinetic adaptations within this range, although they may play a role at doses higher than 12 mg.

Indicators of buprenorphine and methadone use and abuse: what do we know?

Abuse of prescription opioids is a growing problem. The number of methadone pain pills distributed now exceeds liquid methadone used in opioid treatment, and the increases in buprenorphine indicators provide evidence of the need to monitor and intervene to decrease the abuse of this drug. The need for additional and improved data to track trends is discussed, along with findings as to the characteristics of the users and combinations of drugs. Data on toxicities related to methadone or buprenorphine, particularly in combination with other prescribed drugs, are presented and clinical implications and considerations are offered. These findings underscore the need for physicians to be aware of potential toxicities and to educate their patients regarding these issues.

Pharmacokinetic-pharmacodynamic modeling of the effectiveness and safety of buprenorphine and fentanyl in rats

Objective

Respiratory depression is a serious and potentially life-threatening side-effect of opioid therapy. The objective of this investigation was to characterize the relationship between buprenorphine or fentanyl exposure and the effectiveness and safety outcome in rats.

Methods

Data on the time course of the antinociceptive and respiratory depressant effect were analyzed on the basis of population logistic regression PK–PD models using non-linear mixed effects modeling software (NONMEM). The pharmacokinetics of buprenorphine and fentanyl were described by a three- and two-compartment model, respectively. A logistic regression model (linear logit model) was used to characterize the relationship between drug exposure and the binary effectiveness and safety outcome.

Results

For buprenorphine, the odds ratios (OR) were 28.5 (95% CI, 6.9–50.1) and 2.10 (95% CI, 0.71–3.49) for the antinociceptive and respiratory depressant effect, respectively. For fentanyl these odds ratios were 3.03 (95% CI, 1.87–4.21) and 2.54 (95% CI, 1.26–3.82), respectively.

Conclusion

The calculated safety index (OR_{antinociception}/OR_{respiratory depression}) for fentanyl of 1.20 suggests that fentanyl has a low safety margin, implicating that fentanyl needs to be titrated with caution. For buprenorphine the safety index is 13.54 suggesting that buprenorphine is a relatively safe opioid.

The medical management of opioid dependence in HIV primary care settings

Injecting drug use is a common mode of transmission among persons with HIV/AIDS. Many HIV-infected patients meet diagnostic criteria for opioid dependence, a chronic and relapsing brain disorder. Most HIV providers, however, receive little training in substance use disorders. Opioid agonist therapy (OAT) has a stabilizing effect on opioid-dependent patients and is associated with greater acceptance of antiretroviral (ARV) therapy, higher ARV adherence, and greater engagement in HIV-related health care. Although methadone maintenance has been the OAT gold standard, methadone is available for the treatment of opioid dependence only in strictly regulated narcotic treatment programs. Buprenorphine, a partial opioid agonist approved for the office-based treatment of opioid dependence in 2002, may result in better health and substance use treatment outcomes for patients with HIV disease.