Nalmefene hydrochloride
Nalmefene hydrochloride (Revex)
Nalmefene hydrochloride
( NAL-meh-feen)
Pregnancy Category: B Revex (Rx)

Classification: Narcotic antagonist

See Also: See also Narcotic Antagonists .

Action/Kinetics: Prevents or reverses respiratory depression, sedation, and hypotension due to opioids, including propoxyphene, nalbuphine, pentazocine, and butorphanol. Has a significantly longer duration of action than naloxone. Does not produce respiratory depression, psychotomimetic effects, or pupillary constriction (i.e., it has no intrinsic activity). Also, tolerance, physical dependence, or abuse potential have not been noted. Onset, after IV: 2 min. Duration: Up to 8 hr. t 1/2: 10.8 hr. Metabolized by the liver and excreted in the urine.

Uses: For complete or partial reversal of the effects of opioid drugs postoperatively. Management of known or suspected overdose of opiates.

Special Concerns: Will precipitate acute withdrawal symptoms in those who have some degree of tolerance and dependence on opioids. Use with caution during lactation, in high CV risk clients, or in those who have received potentially cardiotoxic drugs. Reversal of buprenorphine- induced respiratory depression may be incomplete; therefore artificial respiration may be necessary. Safety and effectiveness have not been determined in children.

Side Effects: CV: Tachycardia, hypertension, hypotension, vasodilation, bradycardia, arrhythmia. GI: N&V;, diarrhea, dry mouth. CNS: Dizziness, somnolence, depression, agitation, nervousness, tremor, confusion, withdrawal syndrome, myoclonus. Body as a whole: Fever, headache, chills, postoperative pain. Miscellaneous: Pharyngitis, pruritus, urinary retention.

Laboratory Test Alterations: AST.

How Supplied: Injection: 1 mg/mL, 100 mcg/mL

Dosage
?IV Reversal of postoperative depression due to opiates.
Adults: Titrate in 0.25-mcg/kg incremental doses at 2-5-min intervals until the desired degree of reversal is achieved (i.e., adequate ventilation and alertness without significant pain or discomfort). If client is an increased CV risk, use an incremental dose of 0.1 mcg/kg (the drug may be diluted 1:1 with saline or sterile water). A total dose greater than 1 mcg/kg does not provide additional effects.
Management of known or suspected overdose of opiates.
Adults, initial: 0.5 mg/70 kg; then 1 mg/70 kg 2-5 min later, if needed. Doses greater than 1.5 mg/70 kg do not increase the beneficial effect. If there is a reasonable suspicion of dependence on opiates, give a challenge dose of 0.1 mg/70 kg first; if there is no evidence of withdrawal in 2 min, give the recommended dose.