Classifications: narcotic (opiate) antagonist; Therapeutic: narcotic antagonist
Pregnancy Category: B
100 mcg/mL, 1 mg/mL injection
Analog of oxymorphone. A "pure" narcotic antagonist, essentially free of agonistic (morphine-like) properties. Thus,
it produces no significant analgesia, respiratory depression, psychotomimetic effects, or miosis when administered in the
absence of narcotics while processing more potent narcotic antagonist action.
Reverses the effects of opiates, including respiratory depression, sedation, and hypotension. These effects are dose related.
Complete or partial reversal of opioid drug effects, management of opioid overdose.
Hypersensitivity to nalmefene, naloxone, naltrexone, nalnefene; respiratory depression due to non-opioid drugs; substance
Patients at high cardiovascular risk or who have received potential cardiotoxic drugs; patients with known physical dependence
on opioids; renal or hepatic impairment; pregnancy (category B), lactation. Safety and efficacy in children are not established.
Route & Dosage
|Reversal of Postoperative Opioid Depression (use 100 mcg/mL)
Adult: IV/IM/SC 0.25 mcg/kg followed by 0.25 mcg/kg incremental doses q25min until desired degree of reversal or 1 mcg/kg cumulative
dose is reached
Known/Suspected Opioid Overdose (use 1 mg/mL)
Adult: IV/IM/SC For nonopioid-dependent patients: 0.5 mg/70 kg, may repeat with 1 mg/70 kg 25 min later; for opioid-dependent patients:
0.1 mg/70 kg, if no evidence of withdrawal in 2 min, continue with 0.5 mg/70 kg, may repeat with 1 mg/70 kg 25 min
later (doses >1.5 mg/70 kg not likely to be more effective)
- Note: When using the 100 mcg/mL concentration, calculate the volume of a dose equal to 0.25 mcg/kg by multiplying the weight in
kilograms by 0.0025. When using the 1 mg/mL concentration, calculate the volume of a dose equal to 0.1, 0.5, or 1 mg/70
kg by dividing the weight in kilograms by 70, then multiplying that result by the number of milligrams ordered per 70 kg.
- Note: If IV access is lost, a single 1-mg dose may be given IM or SC. Allow 515 min for effect to occur.
PREPARE: Direct: Give undiluted.
ADMINISTER: Direct: Give over 1530 sec. In patients with kidney failure give over 60 sec.
Adverse Effects (≥1%)Body as a Whole:
Fever, chills. CV:
Tachycardia, hypotension, hypertension, pulmonary
edema, ventricular arrhythmias (especially in patients with preexisting
cardiovascular disease). GI: Nausea, vomiting, diarrhea
, dry mouth, dyspepsia, elevation of liver function tests. CNS:
Dizziness, headache, irritability, tremor, paresthesias, confusion, paranoia, drowsiness, fatigue
, vertigo, agitation, nervousness. Special Senses:
Potential risk of seizures when combined with flumazenil.
Well absorbed from IM and SC sites. Onset:
25 min IV
; 15 min IM/SC. Peak:
5 min IV
; 2 h IM/SC. Duration:
48 h. Distribution:
Blocks >80% of brain opioid receptors within 5 min; distributed into breast milk of rats. Metabolism:
In liver by glucuronidation. Elimination:
Metabolites primarily in urine, 17% in feces. Half-Life:
Assessment & Drug Effects
- Monitor carefully for reversal of opioid depression within 25 min of an IV dose or 515 min of an IM/SC dose.
- Note: If recurrent respiratory depression following the reversal, titrate the dose again to avoid over-reversal.
- Monitor cardiovascular status closely, assessing for changes in blood pressure and heart rate and development of arrhythmias.
Patient & Family Education
- Tell your physician all of the other drugs that you are taking including over-the-counter drugs, herbals, and nutritional