Nalmefene Hydrochloride Injection
Dosage form: injection, solution
Drug class:Antidotes
Medically reviewed by Drugs.com. Last updated on Feb 1, 2022.
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Nalmefene Hydrochloride Injection Description
Nalmefene Hydrochloride Injection, an opioid antagonist, is a 6-methylene analogue of naltrexone. The chemical structure is shown below:
Molecular Formula: C21H25NO3∙HCl
Molecular Weight: 375.9, CAS # 58895-64-0
Chemical Name: 17-(Cyclopropylmethyl)-4,5a-epoxy-6-methylenemorphinan-3,14-diol, hydrochloride salt.
Nalmefene hydrochloride is a white to off-white crystalline powder which is freely soluble in water up to 130 mg/mL and slightly soluble in chloroform up to 0.13 mg/mL, with a pKa of 7.6.
Nalmefene Hydrochloride Injection is available as a sterile solution for intravenous, intramuscular, and subcutaneous administration in concentration of 1 mg of nalmefene free base per mL. The 1 mg/mL concentration contains 1.108 mg of nalmefene hydrochloride per mL, 9.0 mg of sodium chloride per mL, and the pH is adjusted to 3.9 with hydrochloric acid.
Concentration and dosage of Nalmefene Hydrochloride Injection are expressed as the free base equivalent of nalmefene.
Nalmefene Hydrochloride Injection - Clinical Pharmacology
Pharmacodynamics
Nalmefene Hydrochloride Injection prevents or reverses the effects of opioids, including respiratory depression, sedation, and hypotension. Pharmacodynamic studies have shown that Nalmefene Hydrochloride Injection has a longer duration of action than naloxone at fully reversing doses. Nalmefene Hydrochloride Injection has no opioid agonist activity.
Nalmefene Hydrochloride Injection is not known to produce respiratory depression, psychotomimetic effects, or pupillary constriction. No pharmacological activity was observed when Nalmefene Hydrochloride Injection was administered in the absence of opioid agonists.
Nalmefene Hydrochloride Injection has not been shown to produce tolerance, physical dependence, or abuse potential.
Nalmefene Hydrochloride Injection can produce acute withdrawal symptoms in individuals who are opioid dependent.
