Overview
DESCRIPTION Naloxone Hydrochloride Injection, USP, an opioid antagonist, is a synthetic congener of oxymorphone. In structure it differs from oxymorphone in that the methyl group on the nitrogen atom is replaced by an allyl group. Naloxone hydrochloride occurs as a white to slightly off-white powder, and is soluble in water, in dilute acids, and in strong alkali; slightly soluble in alcohol;...
Mechanism of Action
CLINICAL PHARMACOLOGY Complete or Partial Reversal of Opioid Depression Naloxone prevents or reverses the effects of opioids including respiratory depression, sedation and hypotension. Also, naloxone can reverse the psychotomimetic and dysphoric effects of agonist-antagonists, such as pentazocine. Naloxone is an essentially pure opioid antagonist, i.e., it does not possess the “agonistic” or morphine-like properties characteristic of other opioid antagonists. When administered in usual doses and in the absence of opioids or agonistic effects of other opioid antagonists, it exhibits essentially no pharmacologic activity. Naloxone has not been shown to produce tolerance or cause physical or psychological dependence.
Indications
- INDICATIONS AND USAGE Naloxone Hydrochloride Injection, USP is indicated for the complete or partial reversal of opioid depression, including respiratory depression, induced by natural and synthetic opioids, including propoxyphene, methadone, and certain mixed agonist-antagonist analgesics: nalbuphine, pentazocine, butorphanol, and cyclazocine. Naloxone Hydrochloride Injection, USP is also indicated for diagnosis of suspected or known acute opioid overdosage.
Common Doses
- 2 mg
- 500 mL
- 0.004 mg
- 0.4 mg
Dosage
DOSAGE AND ADMINISTRATION Naloxone Hydrochloride Injection, USP may be administered intravenously, intramuscularly, or subcutaneously. The most rapid onset of action is achieved by intravenous administration, which is recommended in emergency situations. Since the duration of action of some opioids may exceed that of naloxone, the patient should be kept under continued surveillance. Repeated doses of naloxone should be administered, as necessary. Intravenous Infusion Naloxone Hydrochloride Injection, USP may be diluted for intravenous infusion in normal saline or 5% dextrose solutions.
Contraindications
- CONTRAINDICATIONS Naloxone hydrochloride injection is contraindicated in patients known to be hypersensitive to naloxone hydrochloride or to any of the other ingredients in naloxone hydrochloride injection.
Side Effects
- ADVERSE REACTIONS Postoperative The following adverse events have been associated with the use of naloxone hydrochloride injection in postoperative patients: hypotension, hypertension, ventricular tachycardia and fibrillation, dyspnea, pulmonary edema, and cardiac arrest. Death, coma, and encephalopathy have been reported as sequelae of these events. Excessive doses of naloxone in postoperative patients may result in significant reversal of analgesia and may cause agitation (see PRECAUTIONS and DOSAGE AND ADMINISTRATION; Usage in Adults - Postoperative Opioid Depression ).
Interactions
- Drug Interactions Large doses of naloxone are required to antagonize buprenorphine since the latter has a long duration of action due to its slow rate of binding and subsequent slow dissociation from the opioid receptor. Buprenorphine antagonism is characterized by a gradual onset of the reversal effects and a decreased duration of action of the normally prolonged respiratory depression. The barbiturate methohexital appears to block the acute onset of withdrawal symptoms induced by naloxone in opiate addicts.