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The opioid overdose crisis continues to surge in the United States1


non-fatal opioid-involved overdoses
were treated at emergency departments in 20173
opioid-involved overdose deaths occurred in the US in 20202
involved synthetic opioids2

Synthetic opioids, particularly fentanyl and fentanyl analogs, are highly potent, increasingly available across the United States, and found in the supplies of other illicit drugs.4,5

*Drug overdose deaths are identified using the International Classification of Diseases, 10th Revision (ICD–10) underlying cause-of-death codes X40–X44, X60–X64, X85, and Y10–Y14. Drug overdose deaths involving selected drug categories are identified by specific multiple-cause-of-death codes: any opioid, T40.0–T40.4 and T40.6; heroin, T40.1; natural and semisynthetic opioids, T40.2; methadone, T40.3; and synthetic opioids other than methadone, T40.4. Deaths involving more than one opioid category (eg, a death involving both methadone and a natural or semisynthetic opioid) are counted in both categories. Natural and semisynthetic opioids include drugs such as morphine, oxycodone, and hydrocodone; and synthetic opioids other than methadone include drugs such as fentanyl, fentanyl analogs, and tramadol. The percentage of drug overdose deaths that identified the specific drugs involved varied by year, ranging from 75% to 79% from 1999 through 2013 and increasing from 81% in 2014 to 94% in 2020.2

Opioid half-lives can be variable, and different reversal options may be needed6,7,†


Natural Opioids Morphine7 3 to 4
Synthetic Opioids Fentanyl7,8 2 to 4
Carentanil9 5.7
Tramadol10 6.3
Mathadone7 >12
Semi-synthetic Opioids Heroin11 0.5
Hydromorphone7 2 to 3
Oxycodone12 3 to 5

The National Institutes of Health (NIH) supports the development of stronger, longer-acting formulations of opioid antagonists to counteract high potency synthetic opioids.6

This is not an exhaustive list of all opioids.
Half-lives reported are approximations. Patient- and drug-specific variables may impact the actual half-life of a drug.
Pharmacokinetic data may not necessarily correlate with clinical effects.
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Nalmefene is a long-acting
opioid overdose reversal option
Nalmefene Hydrochloride injection is contraindicated in patients with a known hypersensitivity to the product.


Use of Nalmefene Hydrochloride injection in Emergencies
Nalmefene Hydrochloride injection, like all drugs in this class, is not the primary treatment for ventilatory failure. In most emergency settings, treatment with Nalmefene Hydrochloride injection should follow, not precede, the establishment of a patent airway, ventilatory assistance, administration of oxygen, and establishment of circulatory access.

Risk of Recurrent Respiratory Depression
Accidental overdose with long acting opioids [such as methadone and levo-alpha-acetylmethadol (LAAM)] may result in prolonged respiratory depression. Respiratory depression in both the postoperative and overdose setting may be complex and involve the effects of anesthetic agents, neuromuscular blockers, and other drugs. While Nalmefene Hydrochloride injection has a longer duration of action than naloxone in fully reversing doses, the physician should be aware that a recurrence of respiratory depression is possible, even after an apparently adequate initial response to Nalmefene Hydrochloride injection treatment.

Patients treated with Nalmefene Hydrochloride injection should be observed until, in the opinion of the physician, there is no reasonable risk of recurrent respiratory depression.

Cardiovascular Risks with Narcotic Antagonists
Pulmonary edema, cardiovascular instability, hypotension, hypertension, ventricular tachycardia, and ventricular fibrillation have been reported in connection with opioid reversal in both postoperative and emergency department settings. In many cases, these effects appear to be the result of abrupt reversal of opioid effects.

Although Nalmefene Hydrochloride injection has been used safely in patients with pre-existing cardiac disease, all drugs of this class should be used with caution in patients at high cardiovascular risk or who have received potentially cardiotoxic drugs

Risk of Precipitated Withdrawal
Nalmefene Hydrochloride injection, like other opioid antagonists, is known to produce acute withdrawal symptoms and, therefore, should be used with extreme caution in patients with known physical dependence on opioids or following surgery involving high doses of opioids. Imprudent use or excessive doses of opioid antagonists in the postoperative setting has been associated with hypertension, tachycardia, and excessive mortality in patients at high risk for cardiovascular complications.

Incomplete Reversal of Buprenorphine
Preclinical studies have shown that nalmefene at doses up to 10 mg/kg (437 times the maximum recommended human dose) produced incomplete reversal of buprenorphine-induced analgesia in animal models. This appears to be a consequence of a high affinity and slow displacement of buprenorphine from the opioid receptors. Hence, Nalmefene Hydrochloride injection may not completely reverse buprenorphine-induced respiratory depression.

Use in Pediatric Patients
Safety and effectiveness of nalmefene hydrochloride injection in pediatric patients have not been established.

The most common adverse reactions (>1%) reported in clinical trials with nalmefene injection were nausea (18%), vomiting (9%), tachycardia (5%), hypertension (5%), postoperative pain (4%), fever (3%), and dizziness (3%).

Nalmefene Hydrochloride Injection is indicated for the complete or partial reversal of opioid drug effects, including respiratory depression, induced by either natural or synthetic opioids. Nalmefene Hydrochloride Injection is indicated in the management of known or suspected opioid overdose.
To report SUSPECTED ADVERSE REACTIONS, contact Purdue Pharma L.P. at 1-888-726-7535 or FDA at 1-800-FDA-1088 or FDA MedWatch.

Please read Full Prescribing Information.

References: 1. United States of America Commission on Combating Synthetic Opioid Trafficking. Final Report. Published February 2022. Accessed February 10, 2022. pdf 2. Hedegaard H, Miniño AM, Spencer MR, Warner M. Drug overdose deaths in the United States, 1999-2020. December 2021. Accessed February 10, 2022. 3. Vivolo-Kantor AM, Hoots BE, Scholl L, et al. Nonfatal drug overdoses treated in emergency departments—United States, 2016–2017. MMWR Morb Mortal Wkly Rep. 2020;69(13):371-376. doi:10.15585/mmwr.mm6913a3 4. Mattson CL, Tanz LJ, Quinn K, Kariisa M, Patel P, Davis NL. Trends and geographic patterns in drug and synthetic opioid overdose deaths—United States, 2013-2019. MMWR Morb Mortal Wkly Rep. 2021;70(6):202-207. doi:10.15585/mmwr.mm7006a4 5. National Institute on Drug Abuse. Fentanyl drug facts. June 2021. Accessed February 10, 2022. 6. National Institute on Drug Abuse. Naloxone Drug Facts. June 2021. Accessed February 10, 2022. naloxone 7. Barr J, Fraser GL, Puntillo K, et al. Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit. Crit Care Med. 2013;41(1):263-306. doi:10.1097/CCM.0b013e3182783b72 8. Fentanyl Citrate Injection. Package insert. Akorn, Inc.; 2012. 9. Leen JLS, Juurlink DN. Carfentanil: a narrative review of its pharmacology and public health concerns. Can J Anaesth. 2019;66(4):414-421. doi:10.1007/s12630-019-01294-y 10. Ultram®. Prescribing information. Janssen Ortho, LLC; 2008. 11. Lautieri A. How long does heroin stay in your system? Updated December 20, 2021. Accessed February 10, 2022. how-long-in-system 12. American Addiction Centers. How long do opiates stay in your system? Updated January 28, 2022. Accessed February 10, 2022. https:// american prescription-drugs/how-long-in-system.


Nalmefene Hydrochloride injection is contraindicated in patients with a known hypersensitivity to the product.