EM:RAP COMMENTARY Narcan or Nar-can’t: Tips and Tricks to Safely Reversing Opioid Toxicity Kai Li, MD*; Patil Armenian, MD; Jessica Mason, MD; Andrew Grock, MD *Corresponding Author. E-mail: [email protected], Twitter: @kailimed. 0196-0644/$-see front matter Copyright © 2018 by the American College of Emergency Physicians. https://doi.org/10.1016/j.annemergmed.2018.05.010 SEE RELATED ARTICLE, P. 1. nervous system (CNS) depression. The typical ED starting dose seems to be 0.4 mg administered intravenously. Use of [Ann Emerg Med. 2018;72:9-11.] this dose, like all things in medicine, is well supported by multiple, large, randomized trials. Just kidding! It comes Editor’s Note: Annals has partnered with EM:RAP, enabling our readers without subscriptions to EM:RAP to enjoy their from the 1960s anesthesia literature as the dose needed to commentary on Annals publications. This article did not reverse excessive postoperative sedation in opioid-naive undergo peer review and may not reflect the view and patients.3 Decades later, changes in our patient population opinions of the editorial board of Annals of Emergency and the opioids they use have complicated naloxone dosing. Medicine. There are no financial relationships or other Common unknowns such as the opioid amount, type, consideration between Annals and EM:RAP, or its authors. and tolerance influence naloxone dose and time between doses. Unfortunately, a thin line separates improved ANNALS CASE respiratory rate and symptoms from acute iatrogenic Your next patient is a 34-year-old man with a history of withdrawal. Naloxone-induced opioid withdrawal is, to put intravenous drug use who was brought in by emergency medical it mildly, horrifically uncomfortable for patients. More services. In the field, he had a respiratory rate of 5 breaths/min, important, it can also lead to bad outcomes by increasing decreased mental status, and pinpoint pupils, all of which circulating catecholamines, leading to hyperventilation, significantly improved with out-of-hospital naloxone. He now tachycardia, hypertension, acute respiratory distress hasnormalmentalstatusandnormal vital signs, and admits syndrome, heart failure, and cardiac dysrhythmias!4-6 There to intravenous fentanyl (or so he was told) use. After downing is even evidence that ultrarapid opioid detoxification 3 hospital tuna salad sandwiches, he requests discharge. with naloxone is associated with death.7 Sound familiar? Well, it should. Drug overdose is now the leading cause of injury death in the United States, with frequency tripling from 1999 to 2014.1 Illicit opioids Dosing Option 1: Sleeping Beauty Cocktail for Gentle contribute to the significant increase in opioid-associated Awakenings deaths. The result: you have probably administered naloxone Unfortunately, in patients with long-term opioid use, even the 0.4-mg typical starting dose can precipitate recently once, twice, or even dozens of times to reverse acute 8,9 opioid overdoses. But what is the “standard” dose again? And withdrawal symptoms. This pathophysiology even how long do patients need to be observed? For something we do extends to cancer patients with long-term opioid use for frequently, the lack of evidence-based dosing and observation severe chronic pain. Clearly, no one wants to induce acute timesistroubling.Luckyforus,therecentpublicationby opioid withdrawal in a cancer patient. A gentler approach is Scheuermeyer et al2 examines the safety of an empiric needed whether the naloxone is given for diagnostic or emergency department (ED) protocol for the management therapeutic reasons. Dilute 0.4 mg of naloxone in 10 mL of patients with presumed fentanyl intoxication. After primarily of normal saline solution to produce a solution of 0.04 mg/mL. Then administer it in 1-mL boluses, with the goal intravenous fentanyl use, the majority of patients were > safely discharged after a 2-hour observation period. to improve the respiratory depression (respiratory rate 8 breaths/min). In patients receiving methadone, this gentler, “sleeping beauty” method of reversal can reverse respiratory NAR-CAN! BUT HOW MUCH? and CNS depression, with a median dose requirement Naloxone hydrochloride (Narcan) reverses opioid of just 0.08 mg.10 The upsides: no angry, possibly intoxication symptoms such as respiratory and central aggressive patient with acute withdrawal (aka vomiting and Volume 72, no. 1 : July 2018 Annals of Emergency Medicine 9 EM:RAP Commentary Li et al diarrhea-ing). And no risk of really bad patient outcomes reversal, but not so much that he or she requires more associated with acute withdrawal! The downside is that immediate reversal. Additionally, these patients still need these doses require more bedside vigilance to monitor for close monitoring to ensure that clinical symptoms clinical efficacy. improve.and someone needs to help keep the face mask in place. Dosing Option 2: Waking the Giants On the other hand, the synthetic opioids (eg, fentanyl, carfentanil) require increased amounts of naloxone for Intranasal Naloxone opioid reversal, and their prevalence is increasing. During Intranasal naloxone, although more extensively studied in the out-of-hospital setting, can be useful in ED patients periods of known fentanyl outbreaks, dosing as high as fi 12 mg of naloxone has been reported!11 Although it is with dif cult intravenous access who need immediate universally acknowledged that patients may need escalating reversal. Typical administration is 1 mL of a solution of 1 doses of naloxone to reverse the effects of opioid mg/mL per naris, for a total dose of 2 mg. Out-of-hospital studies show an 83% response rate15 and response rates intoxication, there is no established best protocol. Some 16 articles have suggested increasing the dose of naloxone similar to that of intravenous naloxone. However, the similar rates of response observed in these studies could be every 2 to 3 minutes (from 0.5 to 2 mg, to 4 to 10 mg, and 6 fi 12 related to the delay in obtaining intravenous access. nally 15 mg). Although unimproved CNS or respiratory fi depression after 2 naloxone doses may indicate other cause Potential downsides include dif cult titration and or cointoxicants, no response to a 15-mg dose of naloxone unpredictable absorption, but data in rats describe a 100% fi bioavailability and half-life similar to that of intravenous more de nitively indicates another diagnosis. Anecdotally, 17 some clinicians have doubled the dose of naloxone every 2 naloxone. to 3 minutes (ie, 0.04 to 0.08 to 0.16 mg) until clinical response is achieved. More research needs to be conducted SO THE NAR-CAN WORKED.NOW WHAT? in this area, but, in summary, naloxone should be given in Unfortunately, and perhaps predictably, there is no systematically increasing dosages up to 12 to 15 mg when simple answer because many variables, including the synthetic opioid overdose is suspected. duration of effect, the specific potency and type of opioid Additionally, new routes of administration have made consumed, the administration route, coingestants, and the naloxone administration much easier, especially when patient’s underlying opioid tolerance (to name just a few), venous access is unavailable or difficult to obtain. complicate the opioid’s duration. In one study of healthy patients sedated by opioids, a Nebulized Naloxone 0.4-mg dose of intravenous naloxone reversed the effects Nebulized naloxone (2 mg in 3 mL normal saline within 2 minutes. However, symptoms started to return solution administered through a standard face mask) has after 15 to 30 minutes and completely returned within 45 been touted as an effective method to administer the minutes.18 According to this information, it may be appropriate dose of naloxone for a gentler awakening. The reasonable to discharge a patient without recurrence of purported benefit is its exemplary titratability, or should symptoms after 1 hour of observation if you know that the we say self-titratability. Nebulized naloxone is gradually opioid was short acting and pure. Studies have supported inhaled, in contrast to a single, rapid intravenous bolus. the safety of discharging patients after 1 hour of observation Once CNS depression improves enough, the patient can in the ED after use of heroin.19 However, real life is never (and likely will) remove the face mask. All without the so straightforward. risk for precipitating withdrawal! It sounds brilliant and One argument for prolonged observation is that elegant in principle, but studies so far have shown adulteration of street drugs may prolong the opioid contradicting outcomes, ranging from no improvement intoxication. Street heroin may include fentanyl, over placebo13 to a reduced need for supplementation of diphenhydramine, codeine, morphine, phenobarbital, oxygen and improvement in Glasgow Coma Scale score.14 and diazepam.20 In addition, novel synthetic As such, if a clinically suspected opioid overdose is not opioids (such as U-47700) have unpredictable or responding to nebulized naloxone, intravenous naloxone unknown pharmacokinetics.21 Studies have shown should be given. Based on clinical experience, the recurrence of symptoms from opioid toxicity, requiring practical downsides are that this treatment applies only to repeated reversal from naloxone up to 187 minutes a very limited patient population, a patient with enough after initial naloxone administration.12 There are also opioid-induced CNS or respiratory depression to warrant regional variations in adulterants, making it difficult to 10 Annals of Emergency Medicine Volume 72, no. 1 : July 2018 Li et al EM:RAP Commentary generalize one specific study result to all recreational REFERENCES drug users. 1. Rudd RA, Seth P, David F, et al. Increases in drug and opioid-involved overdose deaths—United States, 2010-2015. MMWR Morb Mortal Wkly Rep. 2016;65:1445-1452. Route of Administration 2. Scheuermeyer FX, DeWitt C, Christenson J, et al. Safety of a brief emergency department observation protocol for patients with The route of administration can change the duration of presumed fentanyl overdose. Ann Emerg Med.