Classifications: central nervous system agent; narcotic (opiate) antagonist
Pregnancy Category: B


0.02 mg/mL, 0.4 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 and possesses more potent narcotic antagonist action.

Therapeutic Effects

Reverses the effects of opiates, including respiratory depression, sedation, and hypotension.


Narcotic overdosage; complete or partial reversal of narcotic depression including respiratory depression induced by natural and synthetic narcotics and by pentazocine and propoxyphene. Drug of choice when nature of depressant drug is not known and for diagnosis of suspected acute opioid overdosage.

Unlabeled Uses

Shock and to reverse alcohol-induced or clonidine-induced coma or respiratory depression.


Respiratory depression due to nonopioid drugs. Safety during pregnancy (other than labor) (category B) or lactation is not established.

Cautious Use

Neonates and children; known or suspected narcotic dependence; cardiac irritability.

Route & Dosage

Opiate Overdose
Adult: IV 0.4–2 mg, may be repeated q2–3min up to 10 mg if necessary
Child: IV 0.01 mg/kg, may be repeated q2–3min up to 10 mg if necessary

Postoperative Opiate Depression
Adult: IV 0.1–0.2 mg, may be repeated q2–3min for up to 3 doses if necessary
Child: IV 0.005–0.01 mg/kg, may be repeated q2–3min up to 3 doses if necessary

Asphyxia Neonatorum
Child: IV 0.01 mg/kg into umbilical vein, may be repeated q2–3min up to 3 doses if necessary



PREPARE: Direct: May be given undiluted.  IV Infusion: Dilute 2 mg in 500 mL of D5W or NS to yield 4 mcg/mL (0.004 mg/mL).  

ADMINISTER: Direct: Give 0.4 mg or fraction thereof over 10–15 sec.  IV Infusion: Adjust rate according to patient response.  

INCOMPATIBILITIES Y-site: Amphotericin B cholesteryl complex.

Adverse Effects (1%)

Body as a Whole: Reversal of analgesia, tremors, hyperventilation, slight drowsiness, sweating. CV: Increased BP, tachycardia. GI: Nausea, vomiting. Hematologic: Elevated partial thromboplastin time.


Drug: Reverses analgesic effects of narcotic (opiate) agonists and narcotic (opiate) agonist-antagonists.


Onset: 2 min. Duration: 45 min. Distribution: Crosses placenta. Metabolism: Metabolized in liver. Elimination: Excreted in urine. Half-Life: 60–90 min.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug