Naltrexone Hydrochloride

Package leaflet (information for patients)

Tradename
Naltrexone Hydrochloride

Dosage form
Tablets 50 mg.

Description
Round, flat, beveled to the edge white tablets with an imprint in the form of the brand name "V" on one side.

Structure
Active ingredient: Naltrexone Hydrochloride 50 mg.
Excipients: microcrystalline cellulose 102, calcium stearate, aerosil ® 200 (hydrophilic pyrogenic silicon dioxide).

Pharmacotherapeutic group
Opioid receptor antagonist

Pharmacological properties
Pharmacological action - blocking opiate receptors.
Competitively blocks the binding of agonists or displaces them from opiate receptors. Reduces or relieves symptoms caused by iv administration of opiates. It has the greatest affinity for mu and kappa receptors.
Effective when taken orally, absorbed in the gastrointestinal tract by 96%. In the liver, almost completely (95%) is converted into pharmacologically active metabolites, incl. in 6-β- naltrexol. T1 / 2 naltrexone - 3.9 hours, 6-β- naltrexol - 12.9 hours; average T1 / 2 depends on the dose and increases with prolonged use. Naltrexone and its metabolites are excreted mainly by the kidneys and with feces (undergoes intestinal-hepatic circulation). The total Cl is 1.5 l / min.
Begins to act in 1–2 hours. With simultaneous long-term administration it prevents the development of physical dependence to morphine, heroin and other opiates. At a dose of 50 mg, it blocks the pharmacological effects of 25 mg of intravenous heroin for 24 hours, a double dose (100 mg) for 48 hours, and 150 mg for 3 days.
Long-term administration does not cause tolerance and dependence. The combination with high doses of opioids leads to an increased release of histamine with a characteristic clinical picture (facial flushing, itching, rash).
In patients with opioid dependence, it causes an attack of withdrawal. In alcoholism, it binds to opioid receptors and blocks the effects of endorphins. Reduces alcohol consumption and prevents relapses within 6 months after a 12-week course of therapy (the success of treatment depends on the patient's consent and his interaction with the doctor).

Indications for use
Treatment of alcohol dependence (as part of combination therapy) and blockade of the effects of exogenously administered opioids ; complex therapy of opioid addiction in order to maintain the patient's condition in which opioids cannot have a characteristic effect; to prevent relapse of opioid dependence after opioid detoxification.

Method of administration and dosage
Treatment of alcoholism: Tablets - 50 mg orally once a day for 12 weeks, intramuscularly - 380 mg once a month. Drug addiction treatment begins only after 7-10 days of abstinence from drug use, confirmed by urinalysis. The initial dose is 25 mg, the patient's condition should be monitored for 1 hour, in the absence of withdrawal syndrome - appoint 50 mg 1 time per day.

Side effects
From the nervous system and sensory organs: anxiety, nervousness, fatigue, general weakness, restless sleep, nightmares, headache, dizziness, blurred vision, confusion, hallucinations, fainting, CNS depression, irritability, anxiety, drowsiness, disorientation, ringing and a feeling of stuffiness in the ears, pain and burning sensations in the eyes, photophobia.
From the side of the cardiovascular system and blood (hematopoiesis, hemostasis): chest pain, increased blood pressure, palpitations, tachycardia, nonspecific ECG changes, phlebitis, lymphocytosis.
From the respiratory system: cough, hoarseness, nasal congestion (congestion of the vessels of the nasal cavity), rhinorrhea, sneezing, bronchial obstruction, difficulty breathing, shortness of breath, nosebleeds, dry throat, increased secretion of mucous phlegm, sinusitis, pharyngitis (including. strep), nasopharyngitis.
From the digestive tract: nausea and / or vomiting, abdominal pain, diarrhea or constipation, frequent defecation, gastrointestinal upset, flatulence, dry mouth, anorexia, decreased / increased appetite, taste perversion, erosive and ulcerative lesions of the gastrointestinal tract, aggravation symptoms of hemorrhoids, increased activity of liver enzymes.
From the musculoskeletal system: arthritis, joint pain, joint stiffness, back pain, limb pain, muscle pain, muscle spasm, muscle twitching, muscle stiffness.
From the genitourinary system: discomfort during urination, increased urination, edematous syndrome (swelling of the face, fingers, feet, legs), sexual dysfunction in men (delayed ejaculation, decreased potency).
Allergic reactions: skin rash, itching, skin flushing (including facial flushing),
Others: fever, chills, increase or decrease in body weight, increased sweating, lymphadenopathy, incl. cervical adenitis; reactions at the injection site (soreness, induration, swelling).

Contraindication
Hypersensitivity to naltrexone ; patients taking opioid analgesics, incl. patients with ongoing physical opioid dependence; patients in a state of acute withdrawal of opioids (opioid withdrawal syndrome); patients who did not undergo a provocative test with naloxone or who have a positive test result for the presence of opioids in the urine; severe liver dysfunction (including acute hepatitis and liver failure); pregnancy, lactation (breastfeeding); children and adolescents up to 18 years old.
With caution: impaired liver and / or kidney function.

Overdose
There is currently no sufficient clinical data on the possibility of drug overdose. If you suspect poisoning, you should prescribe symptomatic treatment and contact a specialized medical institution.

Precautions
Before use, it is necessary to exclude subclinical hepatic failure, during treatment, the level of transaminases should be periodically monitored ; cannot be combined with drugs with hepatotoxic properties. To prevent the development of acute withdrawal symptoms, patients should stop taking opioids and drugs containing them at least 7–10 days in advance ; it is imperative to determine opioids in urine and conduct a provocative test with naloxone ; if these requirements are not met, withdrawal symptoms may appear 5 minutes after administration and continue for 48 hours.
Against the background of naltrexone, in the case of emergency analgesia, only narcotic drugs are used with caution in opiates in an increased dosage (to overcome antagonism), because respiratory depression will be deeper and more prolonged.
Patients should be warned that:
- when seeking medical help, they are obliged to inform medical workers about treatment with naltrexone ;
- in case of pain in the abdomen, darkening of urine, yellowing of the sclera, stop taking and consult a doctor;
- with independent use of heroin and other drugs in small doses, there will be no effect from their use, and a further increase in the dose of drugs will lead to death (respiratory arrest).

Interaction with other medicinal products
When used simultaneously with naltrexone, the effectiveness of opioid receptor agonists (antitussives, analgesics) decreases.

Special instructions
Naltrexone should only be used in cases where the patient has not been taking opioid analgesics for at least 7-10 days.
Use with caution in patients with impaired liver and / or kidney function.
Naltrexone should be discontinued at least 48 hours before surgery, which requires the use of opioid analgesics.
Excessive doses of naltrexone can lead to hepatocellular damage. The administration of naltrexone to patients with acute liver disease should be carefully considered and justified, taking into account the risk of liver dysfunction. When used at recommended doses, naltrexone is not hepatotoxic. Patients should be warned of the risk of liver problems and advised to seek medical attention if symptoms of hepatitis occur. If these symptoms occur, naltrexone treatment should be discontinued. During the treatment period, regular monitoring of liver function is recommended.
It should be borne in mind that with naltrexone, the likelihood of complete recovery from opioid dependence is variable.
Influence on the ability to drive vehicles and mechanisms
During the period of naltrexone use, patients should be careful when driving vehicles and mechanisms, as well as when engaging in other potentially hazardous activities that require increased concentration of attention and speed of psychomotor reactions.

Pregnancy and elbowing
Contraindicated for use during pregnancy and lactation (breastfeeding).

Influence on the ability to drive vehicles and work with mechanisms
Does not affect.

Storage conditions
Store in a dry, dark place at a temperature not exceeding 25 ° C, out of the reach of children.

Shelf life
3 years. Do not use after the expiration date printed on the package.

Vacation conditions
On prescription.

Packaging
Naltrexone Hydrochloride 50 mg Tablets. There are 15 tablets in a blister. 2 blisters are packed in a cardboard box together with an enclosed leaflet.