Intravenous use of illicit buprenorphine/naloxone to reverse an acute heroin overdose

Treatment of opioid overdose: current approaches and recent advances

BACKGROUND

The USA has recently entered the third decade of the opioid epidemic. Opioid overdose deaths reached a new record of over 74,000 in a 12-month period ending April 2021. Naloxone is the primary opioid overdose reversal agent, but concern has been raised that naloxone is not efficacious against the pervasive illicit high potency opioids (i.e., fentanyl and fentanyl analogs).

METHODS

This narrative review provides a brief overview of naloxone, including its history and pharmacology, and the evidence regarding naloxone efficacy against fentanyl and fentanyl analogs. We also highlight current advances in overdose treatments and technologies that have been tested in humans.

RESULTS AND CONCLUSIONS

The argument that naloxone is not efficacious against fentanyl and fentanyl analogs rests on case studies, retrospective analyses of community outbreaks, pharmacokinetics, and pharmacodynamics. No well-controlled studies have been conducted to test this argument, and the current literature provides limited evidence to suggest that naloxone is ineffective against fentanyl or fentanyl analog overdose. Rather a central concern for treating fentanyl/fentanyl analog overdose is the rapidity of overdose onset and the narrow window for treatment. It is also difficult to determine if other non-opioid substances are contributing to a drug overdose, for which naloxone is not an effective treatment. Alternative pharmacological approaches that are currently being studied in humans include other opioid receptor antagonists (e.g., nalmefene), respiratory stimulants, and buprenorphine. None of these approaches target polysubstance overdose and only one novel approach (a wearable naloxone delivery device) would address the narrow treatment window.

Buprenorphine to reverse respiratory depression from methadone overdose in opioid-dependent patients: a prospective randomized trial

Background

Naloxone is the usual drug used in opioid-induced respiratory depression but it has a short half-life, precipitates withdrawal in dependent patients, and thus for persistent reversal of long-acting opioids has to be given by titrated doses and infusions. The partial agonist buprenorphine has a much longer duration of action and causes less severe withdrawal, but still should largely reverse respiratory depression induced by full agonist opioids. We aimed to compare the efficacy/safety of buprenorphine and naloxone in reversing respiratory depression in methadone-poisoned opioid-dependent patients.

Methods

Patients with methadone-induced respiratory depression were randomized to receive naloxone (titrated doses), or lower or higher doses of buprenorphine (10 μg/kg or 15 μg/kg). The primary outcome was immediate reversal of respiratory depression. We also recorded acute opioid withdrawal, need for intubation/recurrent apnea, repeated doses of opioid antagonists, length of hospital stay, other morbidity, and mortality. The study was registered with the Iranian Registry of Clinical Trials (Trial ID: 18265; Approval code: IRCT2015011020624N1).

Results

Eighty-five patients were randomized; 55/56 patients who received buprenorphine had rapid reversal of respiratory depression, which persisted for at least 12 h. Naloxone was effective in 28/29 patients, but often required very high titrated doses (thus delaying time to respond) and prolonged infusions. Intubation (8/29 vs 5/56) and opioid withdrawal (15/29 vs 7/56) were less common with buprenorphine. There were no serious complications or deaths in those receiving buprenorphine. The 15-μg/kg buprenorphine dose appeared to provide a longer duration of action, but precipitated withdrawal more frequently than the 10-μg/kg dose.

Conclusion

Buprenorphine appears to be a safe and effective substitute for naloxone in overdosed opioid-dependent patients. Further studies are warranted to explore the optimal dosing strategy for buprenorphine to consistently maintain reversal of respiratory depression but not precipitate withdrawal.

Trial registration number

IRCT2015011020624N1. Registered 30 September 2015.

Electronic supplementary material

The online version of this article (10.1186/s13054-020-2740-y) contains supplementary material, which is available to authorized users.

Non-Prescribed Buprenorphine Use Mediates the Relationship between Heroin Use and Kratom Use among a Sample of Polysubstance Users

In Asia, Mitragyna speciosa (e.g., "kratom") has been used to mitigate alcohol and drug dependence. Some preliminary findings suggest kratom's potential use as an informal harm-reduction method in the United States, such as an opioid substitute or as a means of lessening opioid withdrawal symptoms. To determine correlates of past-year kratom use among a sample of polysubstance users enrolled in residential recovery programs in Kentucky, an anonymous survey was completed by clients in April 2017. Logistic regression was used to identify significant associations with past-year kratom use. Of the final sample (N = 478), 10.4% reported past-year kratom use. Past-year heroin use, but not past-year prescription opioid (e.g., oxycodone, hydrocodone) use, was significantly associated with kratom use, such that individuals who reported past-year heroin use were 2.5 times more likely to also report past-year kratom use. Non-prescribed buprenorphine (i.e., Suboxone) use partially mediated the relationship between past-year heroin and kratom use by explaining 36% of the association between the two drugs. Though amphetamines were highly preferred, past-year use was negatively correlated with past-year kratom use. Rates of past-year kratom use were lower than rates of alcohol and illicit drug use. Kratom was not preferred over heroin or prescription opioids.

Exposure to fentanyl-contaminated heroin and overdose risk among illicit opioid users in Rhode Island: A mixed methods study

BACKGROUND

Illicit fentanyl use has become wide spread in the US, causing high rates of overdose deaths among people who use drugs. This study describes patterns and perceptions of fentanyl exposure among opioid users in Rhode Island.

METHODS

A mixed methods study was conducted via questionnaire with a convenience sample of 149 individuals using illicit opioids or misusing prescription opioids in Rhode Island between January and November 2016. Of these, 121 knew of fentanyl and reported known or suspected exposure to fentanyl in the past year. Semi-structured interviews were conducted with the first 47 participants.

RESULTS

Study participants were predominantly male (64%) and white (61%). Demographic variables were similar across sample strata. Heroin was the most frequently reported drug of choice (72%). Self-reported exposure to illicit fentanyl in the past year was common (50.4%, n=61). In multivariate models, regular (at least weekly) heroin use was independently associated with known or suspected fentanyl exposure in the past year (adjusted prevalence ratio (APR)=4.07, 95% CI: 1.24-13.3, p=0.020). In interviews, users described fentanyl as unpleasant, potentially deadly, and to be avoided. Participants reporting fentanyl exposure routinely experienced or encountered non-fatal overdose. Heroin users reported limited ability to identify fentanyl in their drugs. Harm reduction strategies used to protect themselves from fentanyl exposure and overdose, included test hits, seeking prescription opioids in lieu of heroin, and seeking treatment with combination buprenorphine/naloxone. Participants were often unsuccessful in accessing structured treatment programs.

CONCLUSION

Among illicit opioid users in Rhode Island, known or suspected fentanyl exposure is common, yet demand for fentanyl is low. Fentanyl-contaminated drugs are generating user interest in effective risk mitigation strategies, including treatment. Responses to the fentanyl epidemic should be informed by the perceptions and experiences of local users. The rapid scale-up of buprenorphine/naloxone provision may slow the rate of fentanyl-involved overdose deaths.

A Question About the Safety of Buprenorphine/Naloxone and Benzodiazepine Drugs

Drug overdose is the leading cause of injury death in the United States, and most deaths are related to prescription drugs. A substantial proportion of these deaths involve opioid or benzodiazepine drugs, and many overdoses include a combination of both drug classes. Buprenorphine/naloxone has an unusual pharmacology that distinguishes it from other opioid drugs. Animal and human studies have found that buprenorphine is associated with a ceiling to its cardio-respiratory depressant effect at higher doses, such that it may have a wider safety margin compared to other opioid drugs. Compared to buprenorphine alone, buprenorphine/naloxone is associated with less cardiorespiratory depression. Drug safety data from the National Poison Data System, Drug Abuse Warning Network, and other sources suggest that the safety of buprenorphine/naloxone is favorable compared to the morbidity and mortality associated with other opioid drugs and other classes of psychotropic drugs.

Association between non-fatal opioid overdose and encounters with healthcare and criminal justice systems: Identifying opportunities for intervention

BACKGROUND

Accidental overdose, driven largely by opioids, is a leading cause of death among people who inject drugs (PWIDs). We conducted secondary analysis of data from a cohort of PWIDs to identify venues where high-risk PWID could be targeted by overdose education/naloxone distribution (OEND) programs.

METHODS

573 PWIDs completed a quantitative survey between June, 2012 and January, 2014, which was analyzed using multivariable logistic regression. The dependent variable was a dichotomous indicator of experiencing a heroin/opioid-related overdose in the past six months. Independent variables included: demographics, drug use behavior, and encounters with two venues - the health care and criminal justice systems - that could serve as potential venues for OEND programs.

RESULTS

Almost half (41.5%) reported ever experiencing a heroin/opioid overdose, and 45 (7.9%) reported experiencing at least one heroin/opioid overdose in the past six months. In the final multivariable model, receiving care in a hospital in the past six months (Adjusted Odds Ratio [AdjOR] 4.08, 95% Confidence Interval [C.I.] 2.07, 8.04, p<0.001) and being arrested for drug possession in the past six months (AdjOR 5.17, 95% C.I. 2.37, 11.24, p<0.001) were associated with experiencing an opioid overdose in the past six months.

CONCLUSIONS

Identifying venues outside of those that traditionally target services to PWIDs (i.e., syringe exchange programs) will be critical to implementing OEND interventions at a scale sufficient to address the growing epidemic of heroin/opioid related deaths. Clinical settings, such as hospitals, and drug-related encounters with law enforcement officers are promising venues for the expansion of OEND programs.