Naltrexone Hcl
Naltrexone Hcl - General Information
Derivative of noroxymorphone that is the N-cyclopropylmethyl congener of naloxone. It is a narcotic antagonist that is effective orally, longer lasting and more potent than naloxone, and has been proposed for the treatment of heroin addiction. The FDA has approved naltrexone for the treatment of alcohol dependence. [PubChem]
Pharmacology of Naltrexone Hcl
Naltrexone Hcl, a pure opioid antagonist, is a synthetic congener of oxymorphone with no opioid agonist properties. Naltrexone Hcl is indicated in the treatment of alcohol dependence and for the blockade of the effects of exogenously administered opioids. It markedly attenuates or completely blocks, reversibly, the subjective effects of intravenously administered opioids. When co-administered with morphine, on a chronic basis, naltrexone blocks the physical dependence to morphine, heroin and other opioids. In subjects physically dependent on opioids, naltrexone will precipitate withdrawal symptomatology.
Naltrexone Hcl for patients
It is recommended that the prescribing physician relate the following information to patients being treated with REVIA:
You have been prescribed REVIA as part of the comprehensive treatment for your alcoholism or drug dependence. You should carry identification to alert medical personnel to the fact that you are taking REVIA. A REVIA medication card may be obtained from your physician and can be used for this purpose. Carrying the identification card should help to ensure that you can obtain adequate treatment in an emergency. If you require medical treatment, be sure to tell the treating physician that you are receiving REVIA therapy.
You should take REVIA as directed by your physician. If you attempt to self-administer heroin or any other opiate drug, in small doses while on REVIA, you will not perceive any effect. Most important, however, if you attempt to self-administer large doses of heroin or any other opioid while on REVIA, you may die or sustain serious injury, including coma.
REVIA is well-tolerated in the recommended doses, but may cause liver injury when taken in excess or in people who develop liver disease from other causes. If you develop abdominal pain lasting more than a few days, white bowel movements, dark urine, or yellowing of your eyes, you should stop taking REVIA immediately and see your doctor as soon as possible.
Naltrexone Hcl Interactions
Studies to evaluate possible interactions between REVIA and drugs other than opiates have not been performed. Consequently, caution is advised if the concomitant administration of REVIA and other drugs is required.
The safety and efficacy of concomitant use of REVIA and disulfiram is unknown, and the concomitant use of two potentially hepatotoxic medications is not ordinarily recommended unless the probable benefits outweigh the known risks.
Lethargy and somnolence have been reported following doses of REVIA and thioridazine.
Patients taking REVIA may not benefit from opioid containing medicines, such as cough and cold preparations, antidiarrheal preparations, and opioid analgesics. In an emergency situation when opioid analgesia must be administered to a patient receiving REVIA, the amount of opioid required may be greater than usual, and the resulting respiratory depression may be deeper and more prolonged.
Naltrexone Hcl Contraindications
REVIA is contraindicated in:
- Patients receiving opioid analgesics.
- Patients currently dependent on opioids.
- Patients in acute opioid withdrawal.
- Any individual who has failed the naloxone challenge test or who has a positive urine screen for opioids.
- Any individual with a history of sensitivity to REVIA or any other components of this product. It is not known if there is any cross-sensitivity with naloxone or the phenanthrene containing opioids.
- Any individual with acute hepatitis or liver failure.
Additional information about Naltrexone Hcl
Naltrexone Hcl Indication: For use in the treatment of alcohol dependence and for the blockade of the effects of exogenously administered opioids.
Mechanism Of Action: Naltrexone Hcl binds to the opioid mu receptor antagonistically, thereby preventing conventional opiate (heroin, morphine) drugs from binding and inducing opioid neural responses. The mechanism of action of naltrexone in alcoholism is not understood; however, involvement of the endogenous opioid system is suggested by preclinical data. Naltrexone Hcl competitively binds to such receptors and may block the effects of endogenous opioids.
Drug Interactions: Alfentanil Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Buprenorphine Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Codeine Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Dihydrocodeine Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Fentanyl Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Heroin Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Hydrocodone Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Hydromorphone Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Levorphanol Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Meperidine Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Methadone Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Morphine Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Nalbuphine Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Sufentanil Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Propoxyphene Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Pentazocine Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Oxymorphone Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Oxycodone Naltrexone Hcl may precipitate a withdrawal syndrome in opioid-dependent individuals
Food Interactions: Not Available
Generic Name: Naltrexone
Synonyms: Not Available
Drug Category: Anti-craving Agents; Depressants; Alcohol Antagonists; Opiate Antagonists
Drug Type: Small Molecule; Approved
Other Brand Names containing Naltrexone: Celupan; N-Cyclopropylmethylnoroxymorphone; Naltrexona [Inn-Spanish]; Naltrexone Hcl; Naltrexone [Usan-Ban-Inn]; Naltrexonum [Inn-Latin]; ReVia; Vivitrex;
Absorption: Although well absorbed orally, naltrexone is subject to significant first pass metabolism with oral bioavailability estimates ranging from 5 to 40%.
Toxicity (Overdose): In the mouse, rat and guinea pig, the oral LD50s were 1,100-1,550 mg/kg; 1,450 mg/kg; and 1,490 mg/kg; respectively. High doses of naltrexone (generally ≥1,000 mg/kg) produce salivation, depression/reduced activity, tremors, and convulsions.
Protein Binding: 21% bound to plasma proteins over the therapeutic dose range.
Biotransformation: Hepatic. When administered orally, naltrexone undergoes extensive biotransformation and is metabolized to 6 beta-naltrexol (which may contribute to the therapeutic effect) and other minor metabolites.
Half Life: 4 hours for naltrexone and 13 hours for the active metabolite 6 beta-naltrexol.
Dosage Forms of Naltrexone Hcl: Tablet Oral
Chemical IUPAC Name: Not Available
Chemical Formula: C20H23NO4
Naltrexone on Wikipedia: https://en.wikipedia.org/wiki/Naltrexone
Organisms Affected: Humans and other mammals