Vivitrol

Vivitrol is a prolonged-release medication that contains naltrexone, an opioid antagonist with the highest affinity for opioid mu-terminals. Apart from its effect on opioid mu-terminals, naltrexone has almost no intrinsic effect. Naltrexone can also constrict the pupils, but the mechanism by which this effect occurs has not yet been determined.

The use of the drug does not cause tolerance, physical, mental or drug dependence. In people with opiate dependence, the use of the drug leads to the appearance of withdrawal syndrome. [ 1 ]

Indications Vivitrol

It is used in people with diagnosed alcohol dependence who are able to stop drinking alcohol before starting treatment (it should be taken into account that the medication does not reduce the intensity or eliminate the signs of ethyl alcohol withdrawal ).

Release form

The drug is released as a lyophilisate for parenteral administration of a prolonged-release suspension - inside 0.38 g vials (1 vial with solvent inside the box). The kit also contains a 1-use syringe, a needle for making the drug and 2 needles for intramuscular injections.

Pharmacodynamics

The drug blocks the effects of opiates by competitively synthesizing with opiate endings within the central nervous system.

At the moment, it has not been possible to determine the exact principle of the development of the drug's influence in people with alcohol dependence, but there are suggestions that the effect of naltrexone develops with the help of the internal opiate system. [ 2 ]

Naltrexone blockade disappears when the dose of opiates is increased, but at the same time, against the background of this effect, manifestations similar to those developing with increased release of histamine arise. [ 3 ]

The suspension of the drug is not used for aversive treatment and does not cause disulfiram-like symptoms in case of taking opiates and alcohol.

Pharmacokinetics

Vivitrol has prolonged activity. When administered intramuscularly, naltrexone is gradually released, showing an initial peak approximately 120 minutes after the injection; a second peak is observed after 2-3 days. After 2 weeks from the injection, there is a slow decrease in plasma naltrexone levels. The substance is detected in the plasma after 1 month after the injection.

The main metabolic component of naltrexone is 6-β-naltrexone.

In case of repeated injections, less than 15% of naltrexone with its active derivative accumulates.

In vitro tests show that a maximum of 21% of naltrexone is synthesized with plasma albumins. The drug is actively transformed inside the body. Hemoprotein P450 does not participate in the metabolic processes of naltrexone. Along with the main derivative (6-β-naltrexone), a number of other derivatives are also formed, from which glucuronide conjugates are formed. After an intramuscular injection of naltrexone, the volumes of 6-β-naltrexone formed are lower than in the case of oral administration.

The active element and its derivatives are excreted via the kidneys; a small amount of the administered portion is excreted unchanged.

The half-life is 5-10 days; this period is directly dependent on the severity of polymer degradation.

Dosing and administration

The drug in the form of a suspension is administered intramuscularly; the drug has a prolonged type of effect. Other methods of using the drug (except for intramuscular injection) are strictly prohibited. It is also forbidden to drink alcoholic beverages at the beginning of treatment.

Vivitrol is used only as part of a comprehensive alcohol dependence treatment program that also includes mandatory psychosocial support.

The drug can be used only in a hospital. The suspension can be prepared and administered only by medical professionals with the appropriate experience and qualifications.

During treatment, the medication is often used in a dosage of 0.38 g (the substance should be administered only intramuscularly), 1 time per month. The suspension is injected deep into the buttock muscle. Injection sites should be alternated, injecting them alternately into the left and right buttocks.

If the next dose of the drug is missed, it must be administered to the patient as quickly as possible.

Naltrexone should not be taken orally before the medication is administered.

The process of making a suspension for intramuscular injections.

During the preparation of the medicine, only the solvent included in the kit is used. During the preparation and administration of the medicine, only those needles that are also included in the medicinal kit should be used. It is prohibited to replace any elements of the medicine (the kit contains all the components required for the preparation and use of the medicine).

The medicine should be taken out of the refrigerator 45-50 minutes before starting to prepare the suspension. It is also necessary to ensure that the medicine does not heat up above 25 °C.

• Application for children

The medicine is not used in pediatrics (under 18 years of age).

Use Vivitrol during pregnancy

Controlled tests of the drug during pregnancy have not been performed. It is necessary to take into account the existing risks and not to use Vivitrol without medical supervision. During testing, the administration of the drug was stopped if pregnancy occurred.

Naltrexone and 6-β-naltrexone are excreted in breast milk. The drug is not used during breastfeeding because it can potentially cause a carcinogenic effect and the development of severe side effects of the drug in the newborn.

Contraindications

Main contraindications:

• hypersensitivity to naltrexone or other components of the drug;
• drug addiction or use of narcotic analgesics;
• active phase of opiate withdrawal syndrome;
• if a provocation test (with the introduction of naloxone) is not passed;
• persons who have a positive urine opiate test (to avoid withdrawal symptoms, opiates should be discontinued 7-10 days before starting Vivitrol treatment; since urine opiate testing cannot provide a 100% guarantee of accuracy, a provocative test with naloxone should be performed before starting therapy).

The drug is not used in people with active hepatopathologies (due to the potential hepatotoxicity of naltrexone (the proportion between the medicinal and hepatotoxic portion is less than 5)).

Caution is necessary in the following cases:

• severe stages of liver dysfunction, in which the development of coagulation disorders and the emergence of complications when performing injections is possible;
• moderate or severe renal failure (testing of the pharmacokinetic properties of the drug in such people has not been performed, but, taking into account the general pharmacokinetic parameters of the drug, such patients may require a change in dosage).

The drug is not used to block opiate activity or to treat opiate addiction, since if the dose of opiates is increased, the blockade of naltrexone disappears, which can cause severe poisoning due to the increase in opiate levels. At the same time, naltrexone increases opiate sensitivity at the end of the drug use cycle, which can also cause poisoning (also potentially fatal) when smaller doses of opiates are administered. Patients should be warned about the inadmissibility of using opiates in combination with naltrexone.

Caution is also needed when administering drugs to people with various bleeding disorders.

Side effects Vivitrol

Testing has identified the development of the following side effects:

• Gastrointestinal dysfunction: nausea, xerostomia, increased frequency of bowel movements, discomfort and pain in the epigastric region, dyspepsia, appetite disorders (may reach anorexia) and vomiting. In addition, taste disturbances, GERD, bloating, various forms of bowel disorders, hemorrhoids, gastroenteritis, colitis, bleeding inside the gastrointestinal tract, intestinal obstruction and perirectal abscess may be observed;
• problems with the functioning of the hepatobiliary system: active phase of cholecystitis, cholelithiasis and increased values of intrahepatic enzymes;
• respiratory disorders: pharyngitis (may be associated with streptococcus) or nasopharyngitis, laryngitis with sinusitis and other respiratory tract infections, sore throat, dyspnea, difficulty breathing and obstruction of the respiratory tract;
• musculoskeletal disorders: pain in the joints, muscles and limbs, joint stiffness, muscle twitching or spasm and arthritis;
• CNS-related symptoms: weakness, agitation, loss of consciousness, dizziness, sleep disorders, headaches (including migraine headaches), irritability and slow reaction. In addition, euphoria, alcohol withdrawal syndrome, seizures, ischemic stroke, delirium, aneurysms associated with cerebral arteries and weakening of intellectual activity may be observed;
• disorders of the cardiovascular system: myocardial infarction, congestive heart failure, increased blood pressure, thrombosis affecting the pulmonary vessels, deep vein thrombosis, angina pectoris, atherosclerosis affecting the coronary arteries, atrial fibrillation and heart rhythm disorders;
• lesions of the blood system: lymphadenopathy or increased white blood cell count;
• changes in test results: increased CPK or eosinophil values (stabilizes during subsequent treatment), decreased platelet counts, and false-positive urine tests for opiates and other individual drugs;
• signs of allergy: pustular rash, anaphylactoid reactions, itching, conjunctivitis and urticaria;
• local symptoms in the area of application of the suspension: swelling, pain and tissue compaction, as well as itching and hematoma. There have been isolated cases of necrosis, abscess, and compaction requiring surgery;
• Other manifestations include asthenia, hyperthermia, toothache, anxiety, weight loss, tremors, and lethargy. Hypovolemia, urinary tract infection, libido disorder, hypercholesterolemia, and heat stroke may also occur.

Hyperhidrosis (also nocturnal) and the development of cellulite were occasionally observed.

During testing, a case with the development of eosinophilic pneumonia was noted, as well as a case with a suspicion of its development. The disease was cured using corticosteroids and antibiotics. It was not possible to establish a direct link between the action of naltrexone and the occurrence of this disease, but in the case of dyspnea and hypoxia of a progressive nature, it is necessary to perform diagnostics and conduct the required treatment.

The use of Vivitrol may provoke suicidal thoughts (also after the end of therapy), which accompany the depression that has developed. People who are administered the drug should be under the supervision of a doctor in order to promptly detect suicidal thoughts and depression.

Overdose

There is limited information regarding toxicity with Vivitrol. Five volunteers did not develop toxic signs when the dose was increased to 784 mg. It is expected that overdose will increase the intensity and likelihood of adverse effects.

Drug intoxication requires symptomatic and supportive measures.

Given the prolonged effect of the medication, after exceeding the dosage, the patient must be monitored for a long time.

Interactions with other drugs

The drug can completely block or weaken the activity demonstrated by opioid analgesics. If pain relief is required in people using Vivitrol, it is necessary to consider options with the introduction of non-narcotic analgesics, regional or local anesthesia, and in addition benzodiazepines or general anesthesia.

If it is impossible to refuse the use of opiates, it is necessary to consider the option of increasing the dosage, which can provoke prolongation and potentiation of respiratory depression. In such situations, it is necessary to choose fast-acting drugs that minimally suppress breathing, and also individually adjust the dose, taking into account the result obtained. In addition, it is necessary to take into account the increased likelihood of developing severe forms of allergy symptoms (arising from histamine release). Regardless of the type of drug selected, it is necessary to closely monitor the patient's condition.

Storage conditions

Vivitrol must be stored in the refrigerator (with a temperature range of 2-8 °C). At a temperature of 25 °C, the medication can be stored for a maximum of 1 week.

It is prohibited to keep the substance at a temperature above 25°C or to freeze it.

Shelf life

Vivitrol in a completely sealed package can be used within 24 months from the date of production of the drug. If the seal of the vials is broken, the use of the medicine is prohibited.

Analogues

The analogs of the drug are substances Tison, Antabuse, Beviplex with Glutargin Alkoklin, Galavit and Relium with Gepar Compositum, and also Muskomed, Vitanam, Sedalit and Prodetoxon. In addition to this, the list includes Tiapride, Alcodez IC and Antakson with Tazepam.

Reviews

Vivitrol is considered a very effective substance that helps with alcohol addiction. Patient reviews show that the drug significantly reduces the symptoms of ethanol withdrawal. Due to this effect, psychological dependence on alcohol is reduced, which increases the effectiveness of combination therapy.