Naltrexone

General characteristics. Structure:

Active ingredient: 50 mg of naltrexone (in the form of a hydrochloride) in 1 tablet.

Excipients: lactoses monohydrate, potato starch, povidone (polyvinylpirrolidone low-molecular medical), кросповидон (полипласдон XL-10), magnesium stearate, silicon dioxide colloid (aerosil).

Pharmacological properties:

Pharmacodynamics. Competitively blocks binding of agonists or forces out them from opiate receptors. Reduces or removes the symptomatology caused by intravenous administration of opiates. The greatest affinity has to a mu - and a kappa receptors.

Pharmacokinetics. It is effective at intake, in digestive tract it is absorbed for 96%. In a liver almost completely (95%) turns into pharmacological active metabolites, including in 6 - beta naltrexone. An elimination half-life of naltrexone - 3,9 h, 6-beta naltrexone - 12,9 h; the average elimination half-life depends on a dose and increases at prolonged use. Naltrexone and his metabolites are removed preferential by kidneys and intestines (is exposed to enterohepatic circulation). The general clearance makes 1,5 l/min.

Begins to work in 1-2 h. At simultaneous long appointment prevents development of physical dependence to morphine, heroin and other opiates. In a dose of 50 mg blocks pharmacological effects of 25 mg in/in the entered heroin during 24 h, a double dose (100 mg) - during 48 h, and 150 mg - for 3 days.

Long appointment does not cause tolerance and dependence. The combination to high doses of opioids leads to the increased release of a histamine with a characteristic clinical picture (face reddening, an itch, rash).

With opioid dependence causes an abstinence attack in patients.

At alcoholism contacts opioid receptors and blocks effects of endorphines. Reduces consumption of alcohol and prevents a recurrence within 6 months after a 12 weeks course of therapy (success of treatment depends on the consent of the patient and his interaction with the doctor).

Indications to use:

Naltrexone apply to prevention of pharmacological effects of exogenous opioids and maintenance of a state, pure from opioids, at patients with opioid dependence. Drug is appointed only after stopping of an abstinence syndrome and after previously carried out desintoxication.

Use of naltrexone is begun in specialized departments on treatment of drug addiction in 7-10 days after the last reception of opioid drug. Further the patient has to be under strict medical control, positive installation on treatment of drug addiction at the patient is necessary.

Naltrexone appoint in complex treatment of alcohol addiction (at the consent of the patient and in combination with psychotherapeutic and social methods), including at a maintenance therapy in the same dosages, as at heroin drug addiction.

Route of administration and doses:

Treatment of alcoholism: inside on 50 mg once a day, 12 week course of treatment prevent a recurrence within 6 months (success of treatment depends on the consent of the patient).

Therapy of drug addiction is begun only after 7-10 day abstentions from the use of opioids confirmed with the provocative test and the analysis of urine for the content of opioids. The patient has to have no syndrome of "cancellation" and signs of abstinence. Treatment is not begun until provocative test with intravenous administration of 0,5 mg of Naloxonum does not become negative. An initial dose of 25 mg, within 1 hour it is necessary to control a condition of the patient, in the absence of an abstinence syndrome - to appoint 50 mg of 1 times a day, this dose blocks 25 mg of the heroin entered intravenously.

Alternative schemes of treatment:

1. 50 mg each weekday and 100 mg on Saturday;
2. 100 mg every other day;
3. 150 mg in 2 days;
4. for example 100 mg (on Monday), 100 mg (on Wednesday) and 150 mg (on Friday).

It is necessary to consider that use of these schemes of treatment increases risk of a hepatotoxic. The course of treatment is defined individually.

Features of use:

Pregnancy and lactation: contraindicated.

The persistent loss of appetite and the progressing weight loss demand the therapy termination.

It is inefficient at treatment of cocaine, and also not opioid medicinal addiction.

It is necessary to warn patients that at the request for medical care they are obliged to inform health workers on treatment by naltrexone;

in case of abdominal pains, darkenings of urine, yellowing of scleras it is necessary to stop reception and to see a doctor; at the independent use of heroin and other drugs in small doses of effect of their use will not be, and further increase in a dose of drugs will lead to death (apnoea).

Side effects:

From the alimentary system: seldom - increase in appetite, dryness in a mouth, a meteorism, aggravation of symptoms of hemorrhoids, digestive tract erosive cankers, an abdominal pain, increase in activity of "liver enzymes".

From a nervous system and sense bodys: more often - extraordinary fatigue, it is rare - an illegibility of visual perception, confusion of consciousness, a hallucination, oppression of the central nervous system, a ring and feeling of a congestion in ears, pain and burning sensation in eyes, a photophobia, irritability, drowsiness, a disorientation in time and space.

From respiratory system: seldom - hoarseness of a voice, a nose congestion (a hyperemia of vessels of a nasal cavity), sneezing, an asthma, dryness in a throat, the raised department of a mucous phlegm, sinusitis.

From cardiovascular system: seldom - a stethalgia, nonspecific changes of an ECG.

From urinogenital system: discomfort at an urination, increase of an urination.

Allergic reactions: less often - skin rash, it is rare - a hyperthermia, a skin itch, is rare - increase in secretion of sebaceous glands.

Others: seldom - thirst, increase or loss of body weight, pain in inguinal area, a hyperadenosis, a lymphocytosis; in one case development of an idiopathic Werlhof's disease against the background of presensitization to drug is described.

Syndrome of "cancellation" of opioids: abdominal pain, spasms in epigastriums, concern, nervousness, fatigue, irritability, diarrhea, tachycardia, a hyperthermia, a rhinorrhea, sneezing, "goose-pimples", perspiration, yawning, an arthralgia, a mialgiya, anorexia, nausea and/or vomiting, a tremor, the general weakness.

Interaction with other medicines:

Increases (mutually) risk of damage of a liver at a combination with hepatotoxic drugs. The lethargy or the increased drowsiness at a combination to thioridazine are possible. Reduces efficiency of the medicines containing opioids (antibechic medicines, analgetics).

Accelerates emergence of symptoms of "withdrawal" against the background of drug addiction (symptoms can appear in 5 minutes after administration of drug, proceed within 48 hours, are characterized by firmness and difficulty of their elimination). Special instructions

Before use it is necessary to exclude a subclinical liver failure, during treatment it is necessary to control the level of transaminases periodically; it is impossible to combine with the drugs having hepatotoxic properties.

For prevention of development of an acute abstinence syndrome patients have to stop at least in 7-10 days reception of the opioids and drugs supporting them definition of opioids in urine and carrying out the provocative test with Naloxonum is obligatory; at non-compliance with these requirements the abstinence syndrome can be shown in 5 min. after administration of drug and proceed within 48 hours.

Naltrexone it is necessary to cancel not less than in 48 hours prior to surgical intervention at which use of opioid analgetics will be required.

In case of need carrying out the emergency analgesia with care appoint opiates in the raised dosage (for overcoming antagonism) as respiratory depression at the same time will be deeper and long.

Contraindications:

Hypersensitivity (including to Naloxonum), reception of opiates, positive test for availability of opioids in urine, an abstinence syndrome, an acute hepatitis, a liver failure, pregnancy, feeding by a breast (for the period of treatment it is excluded), children's and youthful age (up to 18 years).

With care: renal failures.

Overdose:

It is not described.

Storage conditions:

In the place protected from light at a temperature not above 25 °C. To store in the places unavailable to children. A period of validity - 3 years. It is forbidden to use drug after the date specified on packaging.

Issue conditions:

According to the recipe

Packaging:

Tablets of 50 mg. On 10 tablets in a blister strip packaging. On 1,2 or 5 blister strip packagings with the application instruction in a cardboard pack. On 100, 200, 300 blister strip packagings according to 10, 20, 30 application instructions in a box or a box (for hospitals).