Phenybut (Tablets) Instructions for Use

ATC Code

N06BX22 (Phenibut)

Active Substance

Aminophenylbutyric acid (Grouping name)

Clinical-Pharmacological Group

Nootropic drug with anxiolytic activity

Pharmacotherapeutic Group

Psychoanaleptics; psychostimulants, agents used in attention deficit hyperactivity disorder, and nootropic agents; other psychostimulants and nootropic agents

Pharmacological Action

A nootropic agent, it is the hydrochloride of gamma-amino-beta-phenylbutyric acid. It facilitates GABA-mediated transmission of nerve impulses in the CNS (direct effect on GABA receptors), and also has tranquilizing, psychostimulant, antiplatelet, and antioxidant effects.

It improves the functional state of the brain by normalizing tissue metabolism and influencing cerebral circulation (increases volumetric and linear velocity of cerebral blood flow, reduces vascular tone of the brain, improves microcirculation, has an antiplatelet effect). It helps reduce or eliminate feelings of anxiety, tension, restlessness, and fear, normalizes sleep, and has some anticonvulsant action.

It does not affect cholinergic and adrenergic receptors.

It lengthens the latent period and shortens the duration and severity of nystagmus.

It reduces manifestations of asthenia and vasovegetative symptoms (including headache, feeling of heaviness in the head, sleep disturbances, irritability, emotional lability), increases mental performance.

It improves psychological indicators (attention, memory, speed and accuracy of sensory-motor reactions).

With course administration, it increases physical and mental performance, improves memory, normalizes sleep; improves the condition of patients with motor and speech disorders. In patients with asthenia, well-being improves from the first days of therapy; increases interest and initiative (motivation for activity) without sedative effect or excitation. When used after severe traumatic brain injury, it increases the number of mitochondria in perifocal areas and improves the course of bioenergetic processes in the brain.

In neurogenic lesions of the heart and stomach, it normalizes lipid peroxidation processes. In elderly people, it does not cause confusion and excessive lethargy, a relaxing aftereffect is most often absent. It improves microcirculation in the tissues of the eye, reduces the depressant effect of ethanol on the CNS. It has low toxicity.

Pharmacokinetics

Absorption is high, it penetrates well into all body tissues and through the blood-brain barrier (about 0.1% of the administered dose of the drug penetrates into the brain tissue, and to a significantly greater extent in young and elderly individuals). It is evenly distributed in the liver and kidneys. It is metabolized in the liver – 80-95%, metabolites are pharmacologically inactive. It does not accumulate. After 3 hours, it begins to be excreted by the kidneys, while the concentration in the brain tissue does not decrease and it is detected in the brain for another 6 hours. About 5% is excreted by the kidneys unchanged, partially with bile.

Indications

Asthenic and anxiety-neurotic states, anxiety, fear, obsessive-compulsive neurosis, psychopathy. Stuttering and tics in children, enuresis. Urinary retention due to myelodysplasia. Insomnia and nightmares in the elderly. Prevention of anxiety states arising before surgical interventions and painful diagnostic studies (premedication).

Meniere’s disease, dizziness associated with dysfunctions of the vestibular analyzer of various origins (including in otogenic labyrinthitis, vascular and traumatic disorders); prevention of motion sickness in kinetoses.

Primary open-angle glaucoma (as part of combination therapy).

As an auxiliary therapy in the treatment of alcoholism (to relieve psychopathological and somatovegetative disorders in withdrawal syndrome).

Treatment of predelirious and delirious states in alcoholism (in combination with conventional detoxification agents).

ICD codes

Dosage Regimen

Administer orally, regardless of meals.

Adjust the dose, frequency, and duration based on indication, patient age, and individual tolerance.

For adults, a single dose ranges from 20 mg to 750 mg.

For children, a single dose ranges from 20 mg to 250 mg.

For anxiety and asthenic disorders in adults, administer 250-500 mg three times daily.

The maximum daily dose for adults is 2500 mg.

For insomnia, take the last dose immediately before bedtime.

For premedication before surgical procedures, administer 250-500 mg 20-30 minutes prior.

For vestibular disorders and Meniere’s disease, use 250 mg three times daily for 1-2 weeks.

For motion sickness prevention, take a single dose of 250-500 mg one hour before the expected motion stimulus.

For alcohol withdrawal syndrome, administer 250-500 mg three times daily, plus an additional 750 mg at bedtime.

Gradually reduce the dose upon treatment discontinuation to avoid withdrawal syndrome.

For elderly patients, initiate therapy at the lower end of the dosing range.

The duration of treatment typically does not exceed 4-6 weeks.

Re-evaluate the need for continued therapy after the initial course.

Adverse Reactions

From the CNS increased irritability, agitation, anxiety, dizziness, headache, drowsiness.

From the digestive system nausea (during initial doses).

Allergic reactions skin rash, itching.

Contraindications

Hypersensitivity to phenibut.

Use in Pregnancy and Lactation

Use with caution during pregnancy and lactation.

Use in Hepatic Impairment

Use with caution in hepatic insufficiency.

Special Precautions

Use with caution in erosive and ulcerative lesions of the gastrointestinal tract, hepatic insufficiency.

With long-term use, it is necessary to monitor liver function indicators and peripheral blood picture.

It is not very effective in severe manifestations of motion sickness (including uncontrollable vomiting, dizziness).

Effect on ability to drive vehicles and machinery

During the treatment period, it is necessary to refrain from potentially hazardous activities requiring increased attention and high speed of psychomotor reactions.

Drug Interactions

It prolongs and enhances the effect of hypnotics, narcotic analgesics, antiepileptic, antipsychotic, and antiparkinsonian drugs.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.