Naltrexone (Naltrexone)
Overview of Naltrexone
Naltrexone is oral opiate receptor antagonist. Naltrexone is derived from thebaine and is extremely similar in structure to oxymorphone. Like parenteral naloxone, Naltrexone is a pure antagonist (i.e., agonist actions are not apparent) but has better oral bioavailability and much longer duration of action than naloxone. Clinically, Naltrexone is used to help maintain an opiate-free state in patients who are known opiate abusers. It was approved by the FDA in 1984, and for the treatment of alcoholism, it was approved in january 17, 1995. Like naloxone, Naltrexone is a competitive antagonist at opiate receptor subtypes �, , and Like naloxone, Naltrexone is a competitive antagonist at opiate receptor subtypes �, ? and d. It can either prevent or displace opiate agonists from binding at these receptors. It does not antagonize the effects of non-opiates such as cocaine, ethanol, amphetamines, barbiturates, or benzodiazepines.
Indication of Naltrexone
Naltrexone is primarily indicated in conditions like Adjunct to prevent relapse, Amenorrhoea, Heart failure, Induction of ovulation, Opioid addiction, Supraventricular arrhythmias (particularly atrial fibrillation), and can also be given in adjunctive therapy as an alternative drug of choice in Alcohol dependence, Appetite suppresser, Mental illness, Obesity, Pulmonary disease.
Contraindication of Naltrexone
Naltrexone is contraindicated in conditions like Liver diseases,Opioid dependence.
Side Effects of Naltrexone
The severe or irreversible adverse effects of Naltrexone, which give rise to further complications include Hepatic damage, Thrombocytopenic purpura.,The signs and symptoms that are produced after the acute overdosage of Naltrexone include Liver dysfunction.,The symptomatic adverse reactions produced by Naltrexone are more or less tolerable and if they become severe, they can be treated symptomatically, these include Tiredness, Headache, Diarrhea, Anxiety, Restlessness, Abdominal cramps, Skin rashes, GI adverse effects, Somnolence, Nausea and vomiting, Muscle aching, Skin rashes.
Precautions of Naltrexone
Naltrexone should be used only if clearly needed during pregnancy or lactation. It should be used with caution in patients with any pre-existing liver disease or if have any allergy. This must not be used in persons dependent on narcotics. Should be given with cuation to renal pateints.