No

Antidote

Complete or partial reversal of opioid drug effects, including respiratory depression induced by natural or synthetic opioids; reversal of postoperative opioid depression; management of known or suspected opioid overdose

B

Limited information available; do not use in pregnant or lactating women if possible

Hypersensitivity to nalmefene, naltrexone, or components

May induce symptoms of acute withdrawal in opioid-dependent patients; recurrence of respiratory depression is possible if the opioid involved is long-acting; observe patients until there is no reasonable risk of recurrent respiratory depression. Safety and efficacy have not been established in children. Avoid abrupt reversal of opioid effects in patients of high cardiovascular risk or who have received potentially cardiotoxic drugs. Animal studies indicate nalmefene may not completely reverse buprenorphine-induced respiratory depression.

>10%: Gastrointestinal: Nausea

1% to 10%:

Cardiovascular: Tachycardia, hypertension, hypotension, vasodilation

Central nervous system: Fever, dizziness, headache, chills

Gastrointestinal: Vomiting

Miscellaneous: Postoperative pain

<1%: Arrhythmia, bradycardia, nervousness, confusion, somnolence, agitation, depression, pruritus, diarrhea, xerostomia, urinary retention, tremor, myoclonus, pharyngitis

No known symptoms in significant overdose; large doses of opioids administered to overcome a full blockade of opioid antagonists, however, has resulted in adverse respiratory and circulatory reactions

Potential increased risk of seizures may exist with use of flumazenil and nalmefene coadministration

As a 6-methylene analog of naltrexone, nalmefene acts as a competitive antagonist at opioid receptor sites, preventing or reversing the respiratory depression, sedation, and hypotension induced by opiates; no pharmacologic activity of its own (eg, opioid agonist activity) has been demonstrated

Onset of action: I.M., S.C.: 5-15 minutes

Distribution: V_d: 8.6 L/kg; rapid

Protein binding: 45%

Metabolism: Hepatic by glucuronide conjugation to metabolites with little or no activity

Bioavailability: I.M., I.V., S.C.: 100%

T_max: I.M.: 2.3 hours; I.V.: <2 minutes; S.C.: 1.5 hours

Half-life: 10.8 hours

Time to peak serum concentration: 2.3 hours

Elimination: <5% excreted unchanged in urine, 17% in feces; clearance: 0.8 L/hour/kg

Reversal of postoperative opioid depression: Blue labeled product (100 mcg/mL): Titrate to reverse the undesired effects of opioids; initial dose for nonopioid dependent patients: 0.25 mcg/kg followed by 0.25 mcg/kg incremental doses at 2- to 5-minute intervals; after a total dose >1 mcg/kg, further therapeutic response is unlikely

Management of known/suspected opioid overdose: Green labeled product (1000 mcg/mL): Initial dose: 0.5 mg/70 kg; may repeat with 1 mg/70 kg in 2-5 minutes; further increase beyond a total dose of 1.5 mg/70 kg will not likely result in improved response and may result in cardiovascular stress and precipitated withdrawal syndrome. (If opioid dependency is suspected, administer a challenge dose of 0.1 mg/70 kg; if no withdrawal symptoms are observed in 2 minutes, the recommended doses can be administered.)

Dosing adjustment in renal or hepatic impairment: Not necessary with single uses, however, slow administration (over 60 seconds) of incremental doses is recommended to minimize hypertension and dizziness

No information available to require special precautions

No effects or complications reported

This drug can only be administered I.V. You may experience drowsiness, dizziness, or blurred vision for several days; use caution when driving or engaging in tasks requiring alertness until response to drug is known. Small frequent meals and good mouth care may reduce any nausea or vomiting. Report yellowing of eyes or skin, unusual bleeding, dark or tarry stools, acute headache, or palpitations. Breast-feeding precautions: Wait 4 hours before breast-feeding.

Check dosage strength carefully before use to avoid error; monitor patients for signs of withdrawal, especially those physically dependent who are in pain or at high cardiovascular risk

Injection, as hydrochloride: 100 mcg/mL [blue label] (1 mL); 1000 mcg/mL [green label] (2 mL)