Antaxon (Naltrexone) 50mg 10 capsules

Active substance: Naltrexone hydrochloride. 

Naltrexone hydrochloride – white, crystalline substance soluble in water.

Pharmacology

Mode of action – blocking the opiate receptors.

Competitive blocking the binding of agonists or replacing them with opiate receptors. Reduces or eliminates symptoms caused by I / O administration of opiates. It has highest affinity for mu and kappa receptors.

It is effective when taken orally, is absorbed by 96% in the digestive tract. In the liver, almost completely (95%) is converted into a pharmacologically active metabolites, including 6-?-naltrexol. T1 / 2 naltrexone – 3.9 hours, 6-?-naltrexol – 12.9 hours; average T1 / 2 was dose-dependent and increases with prolonged use. Naltrexone and its metabolites are excreted primarily by the kidneys and faeces (undergoes enterohepatic circulation). The total Cl is 1.5 l / min.

It takes effect within 1-2 hours. At the same time long-term administration prevents the development of physical dependence to morphine, heroin, and others. Opiates. At a dose of 50 mg blocks the pharmacological effects of 25 mg / per administered heroin for 24 hours, a double dose (100 mg) – for 48 hours, and 150 mg – 3 days.

Long-term appointment 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 is abstinence attack. Alcoholism binds to opioid receptors and block the effects of endorphin. It reduces the consumption of alcohol and prevent relapse within 6 months after the 12-week course of therapy (treatment success depends on the consent of the patient and his interaction with the doctor).

Application

Opioid addiction (as a secondary drug after the abolition of opioid analgesics), alcoholism.

Contraindications

Hypersensitivity (including to naloxone), the state of abstinence in the background opioid dependence, a positive test for the presence of opioids in the urine, acute hepatitis, liver failure.

Restrictions apply

Violation of the liver and / or kidney disease, pregnancy, breast-feeding, Children and Youth age (up to 18 years).

Pregnancy and breast-feeding

Application of pregnancy is possible only if the potential benefit to the mother outweighs the potential risk to the fetus.

Category effects on the fetus by FDA – C.

When taken orally, naltrexone was observed allocation of naltrexone and 6-?-naltrexol breast milk. Because of the potential carcinogenicity and the likelihood of infants serious adverse events should decide to discontinue drug therapy during breastfeeding or termination of lactation during treatment with the drug, depending on the degree of importance of the therapy for the mother.

Side effects

From the nervous system and sensory organs: anxiety, nervousness, fatigue, weakness, restless sleep, nightmares, headache, dizziness, blurred vision, confusion, hallucinations, fainting, CNS depression, irritability, anxiety, drowsiness, disorientation, ringing and a feeling of fullness in the ears, pain and burning sensation in the eyes, photophobia.

Cardio-vascular system and blood (blood, hemostasis): chest pain, increased blood pressure, palpitations, tachycardia, nonspecific ECG changes, phlebitis, lymphocytosis.

From the respiratory system: cough, hoarseness, nasal congestion (hyperemia of the vessels of the nasal cavity), rhinorrhea, sneezing, bronchial obstruction, difficulty in breathing, shortness of breath, nosebleeds, dry throat, increased separation of mucous expectoration, sinusitis, pharyngitis (incl . strep), nasopharyngitis.

From the digestive tract: nausea and / or vomiting, abdominal pain, diarrhea or constipation, frequent bowel movements, gastrointestinal disorder, flatulence, dry mouth, anorexia, decreased / increased appetite, taste perversion, erosive and ulcerative lesions of the gastrointestinal tract, worsening hemorrhoids symptoms, elevation of liver enzymes.

From the musculoskeletal system: arthritis, joint pain, stiffness in joints, back pain, pain in the extremities, muscle pain, muscle spasm, muscle twitching, stiffness in the muscles.

With the genitourinary system: discomfort when urinating, frequent urination, edema syndrome (swelling of the face, fingers, feet, legs), sexual dysfunction in men (delayed ejaculation, decreased potency).

Allergic reactions: skin rash, pruritus, flushing of the skin (including facial flushing)

Other: fever, chills, increased or decreased weight, increased sweating, lymphadenopathy, including cervical adenitis; injection site reactions (pain, induration, swelling).

Interaction

Increases (mutually) the risk of liver damage when combined with hepatotoxic drugs. There are lethargy, or increased sleepiness when combined with thioridazine.

Dosing and Administration

Inside. Alcoholism Treatment: 50 mg 1 time per day for 12 weeks.

Therapy addiction begin only after 7-10 days of abstinence from opioids, confirmed a provocative test and urinalysis. Initial dose – 25 mg, for 1 hour, should be controlled condition of the patient, in the absence of an abstinence syndrome is introduced the remainder of the daily dose. Naltrexone is administered by 50 mg every 24 hours (this dose is sufficient to prevent the actions of / in the introduction of heroin in a dose of 25 mg). Alternative treatment regimens:

1. 50 mg every weekday and 100 mg on Saturday;

2 100 mg every other day;

3. 150 mg every 2 days;

4. 100 mg, Monday, Wednesday, 100 mg and 150 mg Friday.

Note that the use of these regimens increase the risk of hepatotoxicity. Minimum rate – 3 months recommended – 6 months.

V / m, in the buttock, alternating buttocks. The drug should be administered by qualified medical personnel only using the available components in the package. It is impossible to replace the components of the package. The recommended dose – 380 mg / m once every 1 to 4 weeks.

You can not be administered intravenously! If the patient misses the introduction of the next dose, the next injection should be done as quickly as possible.

Precautions

Before use, you must exclude subclinical liver failure during treatment should periodically monitor transaminase levels; can not be combined with drugs having hepatotoxicity. To prevent the development of acute withdrawal syndrome patients should be at least 7-10 days to stop taking opioids and preparations containing them, be sure to define opioids in the urine and carrying provocative test with naloxone; Failure to comply with the withdrawal syndrome can occur 5 minutes after the administration, and continued for 48 hours.

Against the background of naltrexone in case of emergency only narcotic analgesic drugs with caution prescribed opiates in high dosage (to overcome the antagonism), because wherein the respiratory depression is more profound and long lasting.

It should warn patients that:

• When applying for medical assistance, they are obliged to inform health care providers about treatment with naltrexone;
• In the case of abdominal pain, dark urine, yellowing of the sclera should stop taking and consult a doctor;
• For self-use of heroin and other drugs in small doses, the effect of their use will not, and a further increase in the dose of narcotic drugs will result in death (cessation of breathing).