Naltrexone is a drug used to treat opioid addiction. The active ingredient is included in the composition of 1 tablet: naltrexone hydrochloride - 50 mg.

Pharmacological properties


Naltrexone 50mg is a competitive antagonist that blocks μ-, δ- and κ-receptors. For this reason, it neutralizes the analgesic effect of narcotic analgesic drugs and eliminates euphoria, depression of the respiratory center and other symptoms caused by their ingestion.


Naltrexone 50 mg weakly binds to plasma proteins and penetrates blood-brain and placental barriers. The compound is characterized by biotransformation in the liver. It is eliminated through the kidneys, and for 72 hours with urine, about 70% of the dose is taken out. The elimination half-life is 64 minutes.

Indications for use

Opioid addiction (as an additional drug after the abolition of opioid analgesics);

Alcohol dependence (in the complex treatment).


  • Abstinence syndrome;
  • Hepatitis (acute course);
  • Liver failure;
  • Simultaneous use with opiates;
  • Positive test result for the presence of opioids in urine;
  • Pregnancy and the period of breastfeeding;
  • Age to 18 years;
  • Hypersensitivity to the components of the drug.

Instructions for use Naltrexone 50mg: method and dosage

Naltrexone should be taken orally. The drug can be used only after relief of the withdrawal syndrome and preliminary measures to detoxify the body. Therapy should be started in the departments specializing in the treatment of drug addiction, with at least 7-10 days after the last reception of the opioid drug. With further outpatient treatment of the patient should be strictly monitored. The effectiveness of the therapy is largely determined by the patient's positive attitude toward recovery. For the treatment of alcoholism Naltrexone in the complex therapy appoint 50 mg (1 tablet), the frequency of reception - 1 time per day. With the consent of the patient, taking the drug for 3 months prevents the occurrence of relapses within six months. Treatment of opioid addiction can begin after 7-10 days of abstinence from using opioids, which must be confirmed by a provocative test (negative response to intravenous administration of 0.5 mg of naloxone) and urine analysis for their content. The patient should have no signs of withdrawal and withdrawal symptoms. The first dose is 25 mg, after which the patient within 1 hour should be under the supervision of a doctor. In the future, Naltrexone is prescribed once a day for 50 mg (the dose blocks intravenous administration of 25 mg of heroin). Also, the drug can be used according to alternative schemes (multiplicity of intake - once a day):

Three days a week: 100 mg on Monday and Wednesday, 150 mg on Friday;

Six days a week: 50 mg daily for 5 days (on weekdays), 100 mg on Saturday;

For 100 mg after 1 day or for 150 mg after 2 days.

When choosing a dosing regimen, one should take into account that alternative therapies increase the risk of hepatotoxicity. The doctor determines the duration of the treatment course individually.

Side effects

Cardiovascular system: rarely - nonspecific ECG changes, chest pain;

Nervous system and sense organs: more often - unusual fatigue; Rarely - photophobia, hallucinations, blurred vision, confusion, depression of the central nervous system, ringing and feeling of stuffiness in the ears, pain and burning sensation in the eyes, irritability, drowsiness, disorientation in space and time;

Digestive system: rarely - aggravation of symptoms of hemorrhoids, increased appetite, dry mouth, flatulence, abdominal pain, increased activity of hepatic enzymes, erosive and ulcerative lesions of the gastrointestinal tract;

Genitourinary system: increased frequency of urination, discomfort with urination;

Respiratory system: rarely - dryness in the throat, increased separation of mucous sputum, hoarseness of voice, hyperemia of the vessels of the nasal cavity (nasal congestion), sneezing, dyspnea, sinusitis;

Allergic reactions: less often - skin rash; Rarely - hyperthermia, skin itching, increased secretion of sebaceous glands;

Opioid withdrawal syndrome: epigastric spasms, general weakness, goosebumpiness, arthralgia, abdominal pain, anxiety, fatigue, nervousness, tremor, irritability, tachycardia, diarrhea, hyperthermia, rhinorrhea, sneezing, yawning, sweating, myalgia, anorexia, vomiting And / or nausea;

Other: rarely - thirst, enlarged lymph nodes, pain in the groin, decrease or increase in body weight, lymphocytosis. There is evidence of the development of idiopathic thrombocytopenic purpura against a background of preliminary sensitization to naltrexone hydrochloride.


There is no exact information about Naltrexone 50 mg overdose. If suspected acute intoxication should contact a specialist who prescribes symptomatic therapy. In case of overdose, it is forbidden to administer high doses of opioids, as this can worsen the work of the respiratory and cardiovascular systems, as well as the central nervous system.

Special instructions

Before the start of therapy, subclinical hepatic insufficiency should be excluded. During the use of tablets, Naltrexone should periodically monitor the level of transaminases. Contraindicated joint use with drugs with hepatotoxic properties. To avoid the emergence of an acute withdrawal syndrome, patients should stop taking opioids and preparations containing them at least 7-10 days before the start of therapy. An abstinence syndrome with non-observance of this condition can develop 5 minutes after taking Naltrexone 50mg, its average duration is 48 hours. When carrying out emergency anesthesia to overcome antagonism with caution prescribed higher doses of opiates, while respiratory depression can be deeper and more prolonged. If you need to use opioid analgesics before surgery, Naltrexone should be discontinued no less than 48 hours. Persistent loss of appetite and progressive weight loss require discontinuation of therapy. Naltrexone is ineffective in the treatment of non-opioid and cocaine drug dependence. In cases where it is necessary to seek medical help, patients should inform the medical worker about taking the drug. It is necessary to interrupt therapy and seek medical advice when developing symptoms such as darkening of the urine, abdominal pain, yellowing of the sclera. The use of heroin and other drugs in small doses during the application of Naltrexone to the effect does not lead, an increase in the doses of narcotic drugs can cause a stop of breathing with a fatal outcome.

Application in pregnancy and lactation

Use Naltrexone 50 mg tablets during pregnancy is strongly discouraged. It has been proven that, when given orally, naltrexone and 6-β-naltrexol enter the breast milk. Since the drug is potentially carcinogenic and can cause serious side effects in infants, it is necessary to decide whether to abolish Naltrexone during breastfeeding or to stop lactation during the period of therapy with this medication, depending on the importance of treatment for the mother.

With violations of kidney function

According to the instructions, Naltrexone should be used with caution in patients with acute renal dysfunction.

Drug Interactions

When co-prescribing Naltrexone 50mg tablets with certain drugs, the following effects may develop:

  • Hepatotoxic drugs: an increase in the likelihood of liver damage;
  • Drugs with the content of opioids (antitussive drugs, analgesics): a decrease in their effectiveness;
  • Thioridazine: increased drowsiness, the onset of lethargic sleep.

Reviews about Naltrexone 50 mg

According to reviews, Naltrexone has a beneficial effect on the body. It is a very popular drug for the treatment of alcoholism. Patients report that it proved to be very effective in cases when it was not possible to cope with dependence even through coding.