naltrexone REVIA

Class: Mu Opioid Receptor Antagonist
FDA Indications: Alcohol Dependence, Blockade Of The Effects Of Exogenously Administered Opioids
Off-Label Use: Self-injurious Behaviors, Autism Spectrum Disorder, Impulse Control Disorders, Tobacco Dependence, Trichotillomania
Prescribing
Forms: 25, 50, 100mg tablet; 12 mg/0.6 mL po soln; 380 mg/vial (see Vivitrol) IM
Dose Range: 50 mg/day
Starting: 50 mg once daily

NAMI drug fact sheet

Precautions
Contraindications: Patients receiving opioid analgesics; patients currently dependent on opioids, including those currently maintained on opiate agonists (e.g., methadone) or partial agonists (e.g., buprenorphine); patients in acute opioid withdrawal; anyone who has failed the naloxone challenge test or who has a positive urine screen for opioids
Serious Side Effects: Eosinophilic pneumonia, hepatocellular injury (at excessive doses)
Side Effects: headache, dizziness, nausea, insomnia, fatigue, nervousness
Pharmacodynamics
1° MOA: μ Opioid Receptor Antagonist
Pharmacokinetics
t½: 9 (4-13)° TMAX:
Substrate of: Dihydrodiol dehydrogenase; conjugation
Inhibits: ∅ ; Induces:
Active Metabolites: 6β-naltrexol
DDIs
  • - Patients taking naltrexone may not benefit from opioid containing medicines, such as cough and cold preparations, antidiarrheal preparations, and opioid analgesics
Misc
  • - patient must be opioid-free for 7-10 days prior to naltrexone administration; can be given subcutaneously to test for naltrexone tolerability
  • - studies indicate that 50 mg of naltrexone will block the pharmacologic effects of 25 mg of IV administered heroin for periods as long as 24°
  • - μ receptors contribute to the euphoria and "high" of heavy drinking and ∴ μ antagonism ↓'s the enjoyment of heavy drinking & ↑'s abstinence through disruption of reward circuitry
  • - naltrexone not only increases the chances of attaining complete abstinence from alcohol, but also reduces "heavy drinking"
  • - Using a meta-analysis to derive an NNT for naltrexone shows that about 9 to 20 patients would need to be treated for one successful response
Special Populations

Category C—Except for the reports below in which the naltrexone was discontinued very early in gestation, no other references describing the use of the agent during human pregnancy have been located. Although naltrexone did not produce gross structural abnormalities in any of the animal studies, it did alter some opioid receptors in the brain that appeared to have long-lasting consequences. This potential for behavioral alteration in humans cannot be assessed because of the lack of data, but concern is warranted.

Limited Human Data—Probably Compatible


Dose adjustment not generally necessary for mild impairment; not studied in patients with moderate to severe renal impairment

Hepatically metabolized; contraindicated in acute hepatitis or liver failure; dose adjustment not generally necessary for mild impairment; not studied in patients with severe hepatic impairment; has potential to cause hepatocellular injury when given in excessive doses

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Last updated July 08 2018 15:58:23. Disclaimer: This website does not provide medical advice, nor is it a substitute for clinical judgment.