Maxibren

INSTRUCTIONS FOR MEDICAL USE OF THE MEDICINAL PRODUCT MАXIBREN® (MAXIBREN)

Composition:

Active substance: phenibut;

1 tablet contains 250 mg of phenibut;

Excipients: lactose monohydrate; potato starch; calcium stearate.

Dosage form. Tablets.

Main physico-chemical properties: tablets from white to white with a yellowish tinge, oval-shaped with a biconvex surface.

Pharmacotherapeutic group. Other psychostimulants and nootropic agents.

ATC code N06B X22

Pharmacological Properties

Pharmacodynamics

Phenibut is a derivative of γ-aminobutyric acid and phenethylamine.

Its main effects are anti-hypoxic and anti-amnesic. Phenibut improves memory and attention, facilitates learning processes, and increases physical and mental performance. Psychological parameters (attention, memory, speed and accuracy of sensorimotor reactions) improve under the influence of phenibut. It has been established that phenibut increases the energy potential of neurons by improving mitochondrial function.

Phenibut also has tranquilizing properties: it reduces psychoemotional tension, anxiety, fear, emotional lability, irritability, improves sleep, and prolongs and enhances the effects of hypnotics, narcotic agents, neuroleptics, and anticonvulsants. Phenibut binds exclusively to GABA-β receptors in the brain, thus exerting a moderate calming effect without causing undesirable sedative effects such as drowsiness, dizziness, reduced attention, or impaired performance. The drug prolongs the latent period and reduces the duration and intensity of nystagmus, and has antiepileptic activity. It does not affect cholinergic or adrenergic receptors.

MAXIBREN® significantly reduces symptoms of asthenia and vasovegetative manifestations, including headache and the sensation of heaviness in the head. In patients with asthenia and emotionally labile individuals, phenibut improves general well-being without causing excitation.

Pharmacokinetics

Absorption and Distribution

Phenibut is well absorbed after oral administration and readily penetrates all tissues of the body, crossing the blood-brain barrier effectively (approximately 0.1% of the administered dose penetrates into brain tissue, and to a significantly greater extent in both young and elderly individuals). The highest binding of phenibut occurs in the liver (80%), and this binding is non-specific.

Biotransformation and Excretion

80–95% of phenibut is metabolized in the liver; the metabolites are pharmacologically inactive.

Distribution in the liver and kidneys is close to uniform, while in the brain and blood it is lower than uniform. A significant amount of administered phenibut can be detected in urine within 3 hours, while the concentration of the drug in brain tissue does not decrease—phenibut remains detectable in the brain for up to 6 hours. The following day, phenibut can only be detected in urine; it remains detectable in urine for up to 2 days after administration, but the amount detected constitutes only 5% of the administered dose. No accumulation was observed with repeated administration.

Clinical characteristics

Indications. Asthenic and anxiety-neurotic conditions: restlessness, fear, anxiety.

Insomnia, nocturnal restlessness in elderly people.

For prevention of stress conditions prior to surgeries or painful diagnostic procedures.

Meniere's disease, dizziness associated with vestibular analyzer dysfunction of various origins.

For prevention of kinetosis (a specific condition characterized by nausea, vomiting, prostration, and vestibular dysfunction caused by being in a moving object such as a ship or airplane).

Stuttering, tics in children aged 8 to 14 years.

As an adjunctive agent in the treatment of alcohol withdrawal syndrome.

Contraindications. Hypersensitivity to the components of the drug.

Acute renal failure.

Pregnancy and breastfeeding period.

Interaction with other medicinal products and other forms of interactions. MAXIBREN® can be combined with other psychotropic medicinal products, reducing the doses of phenibut and concomitantly administered drugs.

Phenibut enhances and prolongs the effects of hypnotics, narcotics, neuroleptics, and antiparkinsonian drugs.

Special precautions for use

The medicinal product should be used with caution in patients with gastrointestinal disorders due to the irritant effect of phenibut. To protect the mucosa from the irritating action of phenibut, lower doses should be prescribed to these patients, and the medicinal product should be administered after meals.

During prolonged treatment, blood cell counts and liver function test parameters should be monitored.

The medicinal product contains lactose; therefore, it should not be used in patients with rare hereditary disorders of galactose intolerance, lactase deficiency, or glucose-galactose malabsorption syndrome.

Use during pregnancy or breastfeeding. The use of MAXIBREN® is contraindicated during pregnancy or breastfeeding due to insufficient data on the use of the drug during these periods.

Ability to affect reaction speed when driving or operating machinery. Patients who experience drowsiness, dizziness, or other central nervous system reactions during treatment should refrain from driving vehicles or operating machinery.

Dosage and Administration

MAXIBREN® should be taken orally before meals. The tablet should be swallowed whole with sufficient amount of water. To reduce the irritating effect of phenibut on the gastrointestinal tract (see section "Special Warnings and Precautions for Use"), the medicinal product may be taken after food.

For asthenic and anxiety-neurotic conditions in adults: 250–500 mg (1–2 tablets) three times daily. Maximum single doses: for adults — 750 mg, for elderly patients — 500 mg.

The treatment course lasts 2–3 weeks. If necessary, the treatment duration may be extended to 4–6 weeks.

Children aged 8 to 14 years: 250 mg (1 tablet) three times daily.

The treatment course lasts 2–6 weeks.

Meniere’s disease and dizziness associated with vestibular dysfunction of various origins. In vestibular dysfunction of infectious origin and Meniere’s disease during exacerbation, MAXIBREN® should be administered at 750 mg (3 tablets) three times daily for 5–7 days; after reduction in severity of vestibular disturbances — 250–500 mg (1–2 tablets) three times daily for 5–7 days, followed by 250 mg once daily for 5 days. In cases of relatively mild disease course, MAXIBREN® should be administered at 250 mg (1 tablet) twice daily for 5–7 days, followed by 250 mg once daily for 7–10 days.

For relief of dizziness in vestibular dysfunction of vascular and traumatic origin: MAXIBREN® should be administered at 250 mg three times daily for 12 days.

For prevention of kinetosis: the medicinal product should be taken at a dose of 250–500 mg as a single dose one hour before the expected onset of motion sickness or upon appearance of the first symptoms of motion discomfort.

For management of alcohol withdrawal syndrome: during the first days of treatment, MAXIBREN® should be administered at 250–500 mg three times daily and 750 mg at night, with gradual reduction of the daily dose to the usual adult dose.

Patients with hepatic insufficiency

High doses of the medicinal product may cause hepatotoxicity in patients with hepatic insufficiency. Lower doses should be prescribed to this patient group.

Patients with renal insufficiency

There are no data on adverse effects of the medicinal product MAXIBREN® in patients with impaired renal function when therapeutic doses are used.

No drug dependence or withdrawal syndrome has been observed during use of this medicinal product.

Scientific publications report isolated cases of tolerance to phenibut.

Children. The medicinal product may be used in children aged 8 years and older.

Overdose. Data on overdose are lacking. MAXIBREN® is a low-toxicity medicinal product; however, daily doses of 7–14 g during prolonged use may be hepatotoxic. These doses significantly exceed the recommended average therapeutic doses according to patient age (average therapeutic dose is 500–2000 mg).

Symptoms: drowsiness, nausea, vomiting, dizziness.

With prolonged use of high doses of phenibut, arterial hypotension, acute renal failure, eosinophilia, and fatty liver degeneration may develop.

Treatment: gastric lavage. Symptomatic therapy.

There is no specific antidote.

Side effects

MAXIBREN®, like other medicinal products, may cause adverse reactions, although they do not occur in all patients.

Classification of adverse reactions by frequency of occurrence: very common (≥ 1/10); common (≥ 1/100 to < 1/10); uncommon (≥ 1/1000 to < 1/100); rare (≥ 1/10,000 to < 1/1000); very rare (< 1/10,000); frequency not known (cannot be estimated from the available data).

From the nervous system: frequency not known — drowsiness (at the beginning of treatment), headache and dizziness (when doses above 2000 mg per day are used; the intensity of this adverse effect decreases with dose reduction).

From the gastrointestinal tract: frequency not known — nausea (at the beginning of treatment), vomiting, diarrhea, epigastric pain.

From the hepatobiliary system: frequency not known — hepatotoxicity (with long-term use of high doses).

From the immune system: frequency not known — hypersensitivity reactions, including urticaria, erythema, rash, angioneurotic edema, facial swelling, tongue swelling.

From the skin and subcutaneous tissues: rare — allergic reactions (rash, itching).

From the psyche: frequency not known — emotional lability, sleep disturbances (these adverse reactions may occur in children if the instructions for medical use of the medicinal product are not followed).

If any adverse reactions not listed in this instruction appear during treatment, or if any of the listed adverse reactions are particularly severe, medical advice should be sought immediately.

Reporting of suspected adverse reactions

Reporting of adverse reactions after medicinal product registration is of great importance. It enables ongoing monitoring of the benefit-risk balance of the medicinal product. Medical and pharmaceutical professionals, as well as patients or their legal representatives, are encouraged to report all suspected adverse reactions and lack of efficacy via the Automated Pharmacovigilance Information System at: https://aisf.dec.gov.ua.

Shelf life. 3 years.

Storage conditions. Store in the original packaging at a temperature not exceeding 25 °C.

Keep out of reach of children.

Packaging. 10 tablets in a blister. 2 blisters in a cardboard box.

Prescription status. Prescription only.

Manufacturer. ASTRAFARM LLC.

Manufacturer's address and location of operations.

6, Kyivska Street, Vyshneve, Buchanskyi district, Kyiv region, 08132, Ukraine.