Comparison of lower-dose versus higher-dose intravenous naloxone on time to recurrence of opioid toxicity in the emergency department

The Optimal Initial Dose and Route of Naloxone Administration for Successful Opioid Reversal: A Systematic Literature Review

This systematic literature review aims to determine the optimal initial dose of naloxone for successful opioid overdose reversal across different administration routes. Types of participants included adults who have opioid overdoses and adults who are suspected to have opioid overdoses. Pregnant women, children, animals, and populations outside the US were excluded. The interventions included were intranasal (IN), intramuscular (IM), and intravenous (IV) naloxone administration. The data collected for this systematic review were studies from PubMed, CINAHL, PsyINFO, and Cochrane Central Register of Controlled Trials registers between January 2015 and July 2021. The risk of bias was assessed via the Review Manager application. Six studies met the inclusion criteria. A meaningful statistical analysis was unable to be conducted with such few studies. The studies reveal 2 mg IN as the most popular dosing for initial naloxone for successful opioid reversal. The most common route of naloxone administration for successful reversal could not be studied but most studies revealed successful initial naloxone dosing in IN equivalents. With minimal studies emerging from our review, further research is warranted in naloxone dosing for optimal opioid reversal in order to fully treat patients. Healthcare workers must be vigilant of potential withdrawal from high naloxone dosing as well as the inefficiency of lower naloxone dosing for adequate opioid overdose reversal in order to treat patients with opioid overdoses properly.

Systematic Review of Naloxone Dosing and Adverse Events in the Emergency Department

BACKGROUND

Experts recommend using the lowest effective dose of naloxone to balance the reversal of opioid-induced respiratory depression and avoid precipitated opioid withdrawal, however, there is no established dosing standards within the emergency department (ED).

OBJECTIVES

The aim of this review was to determine current naloxone dosing practice in the ED and their association with adverse events.

METHODS

We conducted a systematic review by searching PubMed, Cochrane, Embase, and EBSCO from 2000-2021. Articles containing patient-level data for initial ED dose and patient outcome had data abstracted by two independent reviewers. Patients were divided into subgroups depending on the initial dose of i.v. naloxone: low dose ([LD], < 0.4 mg), standard dose ([SD], 0.4-2 mg), or high dose ([HD], > 2 mg). Our outcomes were the dose range administered and adverse events per dose. We compared groups using chi-squared difference of proportions or Fisher's exact test.

RESULTS

The review included 13 articles with 209 patients in the results analysis: 111 patients in LD (0.04-0.1 mg), 95 in SD (0.4-2 mg), and 3 in HD (4-12 mg). At least one adverse event was reported in 37 SD patients (38.9%), compared with 14 in LD (12.6%, p < 0.0001) and 2 in HD (100.0%, p = 0.16). At least one additional dose was administered to 53 SD patients (55.8%), compared with 55 in LD (49.5%, p < 0.0001), and 3 in HD (100.0%, p = 0.48).

CONCLUSIONS

Lower doses of naloxone in the ED may help reduce related adverse events without increasing the need for additional doses. Future studies should evaluate the effectiveness of lower doses of naloxone to reverse opioid-induced respiratory depression without causing precipitated opioid withdrawal.

Oral and buccal abuse of transdermal opioids : an underdetected but potentially lethal practice

Objectives : Transdermal opioid patches (TOPs) are effective and well tolerated in patients with moderate to severe chronic pain syndromes. Their specific pharmacological properties, however, make them prone to abuse. The objective of this article is to describe the practice of oral and buccal abuse of TOPs and to discuss its clinical implications. Methods : We present the case of a patient admitted to the intensive care unit after oral abuse of transdermal opioid patches. Additionally, a narrative literature review on the topic is conducted, referring to Pubmed and Embase. Results : Oral or buccal TOP abuse is the most frequent method of TOP abuse, followed by intravenous injection, inhaling, and applying multiple patches. The main reasons for TOP abuse include drug addiction, suicidal behavior and self-medication. Oral ingestion is potentially lethal because of the high doses of fentanyl that are found in a single patch. Buccal abuse results in fast elevations of fentanyl serum concentrations, caused by transmucosal absorption of fentanyl, thus bypassing hepatic metabolism. During emergency management, naloxone should be administered in a continuous infusion, given the high risk of recurrence of symptoms. Evidence suggests that transdermal buprenorphine is safer in terms of abuse potential. This is explained by its ceiling effect for respiratory depression and its lower peak effects in supratherapeutic doses. Risk factors for abuse include history of substance use disorder, prior opioid overdose and mental illness. Patients with suspected opioid abuse should be referred to pain clinics, mental health specialists or drug addiction facilities. Conclusion : Oral or buccal abuse is the most reported non-dermal form of TOP abuse. When ingested or chewed, TOPs pose considerable health risks. It is critical to screen patients with chronic opioid therapy regularly for opioid use disorder. When confronted with patients at risk of abuse, close monitoring and referral to specialist care is advised.

Comparison of rates of opioid withdrawal symptoms and reversal of opioid toxicity in patients treated with two naloxone dosing regimens: a retrospective cohort study

INTRODUCTION

When managing opioid overdose (OD) patients, the optimal naloxone regimen should rapidly reverse respiratory depression while avoiding opioid withdrawal. Published naloxone administration guidelines have not been empirically validated and most were developed before fentanyl OD was common. In this study, rates of opioid withdrawal symptoms (OW) and reversal of opioid toxicity in patients treated with two naloxone dosing regimens were evaluated.

METHODS

In this retrospective matched cohort study, health records of patients who experienced an opioid OD treated in two urban emergency departments (ED) during an ongoing fentanyl OD epidemic were reviewed. Definitions for OW and opioid reversal were developed a priori. Low dose naloxone (LDN; ≤0.15 mg) and high dose naloxone (HDN; >0.15 mg) patients were matched in a 1:4 ratio based upon initial respiratory rate (RR). The proportion of patients who developed OW and who met reversal criteria were compared between those treated initially with LDN or HDN. Odds ratios (OR) for OW and opioid reversal were obtained via logistic regression stratified by matched sets and adjusted for age, sex, pre-naloxone GCS, and presence of non-opioid drugs or alcohol.

RESULTS

Eighty LDN patients were matched with 299 HDN patients. After adjustment, HDN patients were more likely than LDN patients to have OW after initial dose (OR = 8.43; 95%CI: 1.96, 36.3; p = 0.004) and after any dose (OR = 2.56; 95%CI: 1.17, 5.60; p = 0.019). HDN patients were more likely to meet reversal criteria after initial dose (OR = 2.73; 95%CI: 1.19, 6.26; p = 0.018) and after any dose (OR = 6.07; 95%CI: 1.81, 20.3; p = 0.003).

CONCLUSIONS

HDN patients were more likely to have OW but also more likely to meet reversal criteria versus LDN patients.

One single large intramuscular dose of naloxone is effective and safe in suspected heroin poisoning

OBJECTIVE

Naloxone is an established antidote for the treatment of heroin poisoning; however, dosing regimens vary widely, with a current trend towards small titrated intravenous dosing. This study aims to characterise naloxone use in the treatment of patients presenting with suspected heroin poisoning.

METHODS

This was a retrospective review of poisoned patients presenting to a clinical toxicology unit in Brisbane from January 2015 to December 2017. Patient demographics, clinical effects, naloxone dosing, observation periods and complications were extracted from the patient's medical records.

RESULTS

There were 117 presentations accounted for by 108 patients. Prehospital naloxone was provided to 57 (49%) patients, 46 of which received a standardised 1.6 mg i.m. dose. The remaining 60 (51%) patients received their first naloxone in hospital, with 58 (97%) receiving this by titrated i.v. doses. A subsequent naloxone infusion was required significantly more often in those treated with i.v. titrated naloxone compared to i.m. dose (27/69 [39%] vs 5/48 [10%], P = 0.0006). The need for parenteral sedation to manage acute behavioural disturbance following naloxone provision was rare (3/117 [3%]).

CONCLUSIONS

In this retrospective observational study, a single large i.m. dose of naloxone reversed the toxicity of suspected heroin overdose in the majority of patients. In addition, patients were less likely to require repeated intermittent doses or naloxone infusion than those treated solely with i.v. naloxone. Further comparison in a prospective study is warranted to validate these observations in confirmed heroin overdose. Requirement for sedation secondary to acute behavioural disturbance was rare regardless of the route.