Quattrex

INSTRUCTION FOR MEDICAL USE OF THE MEDICINAL PRODUCT KVAATTREKS (QUATTREX)

Composition:

Active substance: phenibut;

1 capsule contains 250 mg of phenibut;

Excipients: microcrystalline cellulose, sodium croscarmellose, colloidal anhydrous silicon dioxide, magnesium stearate, talc; capsule shell composition: gelatin, titanium dioxide (E 171).

Pharmaceutical form. Capsules.

Main physicochemical properties: hard gelatin capsules of white color.

The contents of the capsules – powder of white or almost white color.

The presence of compacted columns or lumps which disintegrate upon pressure is permitted.

Pharmacotherapeutic group.

Other psychostimulants and nootropic agents. ATC code N06B X22.

Pharmacological Properties

Pharmacodynamics

Nootropics are also referred to as psychometabolic stimulants because they favorably influence metabolic processes in the brain. Phenibut is a derivative of γ-aminobutyric acid (GABA) and β-phenylethylamine. Phenibut exhibits both nootropic and anxiolytic (tranquilizing) activity typical of GABA derivatives. Phenibut does not affect cholinergic or adrenergic receptors. It reduces anxiety, apprehension, fear, and improves sleep; therefore, the drug can be used in the treatment of neuroses and also preoperatively. Phenibut prolongs and enhances the effects of hypnotics, narcotics, neuroleptics, and antiparkinsonian agents. It does not possess anticonvulsant activity. Phenibut prolongs the latent period of nystagmus and reduces its duration and intensity. Phenibut significantly reduces manifestations of asthenia and vasovegetative symptoms, including headache, sensation of heaviness in the head, sleep disturbances, irritability, emotional lability, and increases mental performance. Phenibut improves psychological parameters—attention, memory, speed and accuracy of sensorimotor reactions.

In patients with asthenia and emotionally labile patients, well-being improves from the first days of treatment with the drug, interest and initiative increase, and motivation for active engagement improves, without sedative or stimulating effects. In terms of antiasthenic activity (fatigue, tiredness, hypodynamia, mental and physical asthenia), phenibut is more active than piracetam.

Pharmacokinetics

Absorption and Distribution

The drug is well absorbed from the gastrointestinal tract after oral administration and penetrates well into all body tissues, readily crossing the blood-brain barrier (approximately 0.1% of the administered dose penetrates into brain tissue, more significantly in both young and elderly individuals). The highest binding of phenibut occurs in the liver (80%), and it is not specific. In healthy volunteers, maximum plasma concentration (Cmax) of the active substance after a single 250 mg oral dose taken with food is reached approximately within 3 hours. Cmax after a single 250 mg oral dose is approximately 2593 ng/mL, and steady-state Cmax on day 4 after repeated oral administration of 250 mg three times daily is approximately 4057 ng/mL.

Biotransformation and Elimination

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

Distribution in the liver and kidneys is close to uniform, whereas in the brain and blood it is lower than uniform. Approximately 5% of the dose is excreted unchanged in urine. With repeated administration, no accumulation is observed.

The elimination half-life in healthy volunteers is approximately 7 hours after a single 250 mg oral dose administered after food intake, and approximately 8 hours on day 4 after repeated oral doses of 250 mg administered three times daily.

Clinical characteristics.

Indications.

Asthenic and anxiety-neurotic states: restlessness, fear, anxiety; insomnia, nocturnal restlessness in elderly people; prevention of stress conditions prior to surgical procedures.

Meniere's disease and vertigo associated with vestibular analyzer dysfunction of various origins.

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

Stuttering, tics in children aged 8 to 14 years.

As an adjunctive agent during treatment of alcohol withdrawal syndrome.

Contraindications.

Hypersensitivity to the components of the drug. Pregnancy and lactation period.

Interaction with other medicinal products and other forms of interactions.

KvatTreks can be combined with psychotropic medicinal products, reducing the doses of both KvatTreks and the concomitantly used medicinal products.

KvatTreks potentiates and prolongs the effect of sedatives, narcotics, neuroleptics, and antiparkinsonian medicinal products.

Special precautions for use

Caution should be exercised in patients with gastric or intestinal ulcers. To protect the mucosa from the irritating effect of phenibut, lower doses should be prescribed for these patients. With prolonged use, blood cell counts and liver function test parameters should be monitored.

Literature data indicate the development of dependence after using medicinal products containing phenibut at doses exceeding the therapeutic dose.

Post-marketing experience with phenibut use at therapeutic doses does not indicate the development of withdrawal syndrome. However, literature data suggest that abrupt discontinuation of phenibut administered at doses higher than therapeutic may lead to withdrawal syndrome, which can be severe and require hospitalization. In some cases, insomnia, psychomotor agitation, psychosis, auditory and visual hallucinations, anxiety, depression, dizziness, seizures, nausea, vomiting, palpitations, and tachycardia have been reported.

Use during pregnancy or breastfeeding

Animal studies have not revealed mutagenic, teratogenic, or embryotoxic effects of phenibut. The use of Quatrec during pregnancy or breastfeeding is contraindicated due to insufficient data on the use of the drug during these periods.

Information regarding the effect of phenibut on fertility is lacking.

Ability to influence reaction rate when driving or operating machinery

Patients who experience drowsiness or other central nervous system disturbances during treatment with the drug should refrain from driving or operating machinery.

Method of Administration and Dosage

Method of Administration

Take orally after meals with sufficient amount of water.

Adults

For asthenic and anxiety-neurotic conditions in adults: administer 250–500 mg three times a day. The maximum single dose is 750 mg; for elderly patients, the maximum single dose is 500 mg.

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

For Ménière’s disease and dizziness associated with vestibular dysfunction of various origins

For infectious vestibular dysfunction and acute exacerbations of Ménière’s disease:

• 750 mg three times a day for 5–7 days,
• after reduction in severity of vestibular disorders, continue treatment at a dose of 250–500 mg three times a day for 5–7 days, followed by 250 mg once daily for 5 days.

For relatively mild disease courses, the medicinal product Quattrex should be administered at 250 mg 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: administer the medicinal product Quattrex at 250 mg three times a day for 12 days.

For prevention of motion sickness: administer a single dose of 250–500 mg one hour before the anticipated onset of motion sickness or upon the appearance of first symptoms.

The drug is poorly effective if pronounced symptoms are already present (e.g., vomiting).

For management of alcohol withdrawal syndrome: during the initial days of treatment, the medicinal product Quattrex is administered at 250–500 mg three times daily and 750 mg at night, with gradual reduction of the daily dose.

Patients with hepatic impairment

High doses of the drug may cause hepatotoxicity in patients with hepatic impairment. Lower doses should be prescribed for this patient group.

Patients with renal impairment

There is no evidence of adverse effects of phenibut on patients with impaired renal function when administered at therapeutic doses.

No drug dependence or withdrawal syndrome has been observed during use of this medicinal product. Literature reports isolated cases of tolerance development associated with phenibut therapy.

Children

In children aged 8 to 14 years: 250 mg three times daily; treatment duration is 2 to 6 weeks. The medicinal product is not used in children under 8 years of age.

Overdose.

The drug is low in toxicity at therapeutic doses.

Symptoms: drowsiness, nausea, vomiting, dizziness.

Prolonged use of high doses may lead to arterial hypotension, acute renal failure, eosinophilia, and fatty liver dystrophy.

Post-marketing data indicate serious cases of phenibut overdose, presenting with symptoms such as depression (including decreased level of consciousness, reduced muscle tone, stupor, respiratory depression), impaired thermoregulation, hypertension or hypotension, and tachycardia. Psychomotor agitation, hallucinations, seizures, and delirium have also been reported. Overdose cases were associated with use of phenibut-containing medicinal products at doses exceeding the therapeutic range.

Treatment: symptomatic therapy.

There is no specific antidote.

Adverse reactions

The medicinal product Quattrex, 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 (≥ 1/1,000 to < 1/100); rare (≥ 1/10,000 to < 1/1,000); very rare (< 1/10,000); frequency not known (cannot be estimated from the available data).

Immune system disorders: frequency not known – hypersensitivity reactions, including rash, pruritus, urticaria, erythema, angioneurotic edema, facial swelling, tongue swelling.

Nervous system disorders: frequency not known – drowsiness (at the beginning of treatment), headache and dizziness (at doses above 2 g per day; the intensity of this adverse effect decreases with dose reduction).

Gastrointestinal disorders: frequency not known – nausea (at the beginning of treatment).

Hepatobiliary disorders: frequency not known – hepatotoxicity (with long-term use of high doses).

Skin and subcutaneous tissue disorders: rare – allergic reactions (rash, pruritus).

There is some evidence that incorrect use in children may lead to emotional lability and sleep disturbances.

Reporting of suspected adverse reactions

Reporting of suspected adverse reactions after registration of the medicinal product is important. It allows continuous monitoring of the safety profile and assessment of the benefit-risk balance of the medicinal product.

Shelf life

2 years.

Do not use after the expiry date stated on the packaging.

Storage conditions

Store in the original packaging in a place inaccessible to children, at a temperature not exceeding 25 °C.

Packaging

10 capsules in a blister; 2 blisters in a cardboard pack.

Prescription status

Prescription only.

Manufacturer

LLC "Pharma Start".

Manufacturer's address and location of its business activity

8 Vatslava Havela Boulevard, Kyiv, 03124, Ukraine.

In case of adverse effects or questions regarding the safety of use of the medicinal product, please contact the Pharmacovigilance Department of LLC "ASINO UKRAINE" at: 8 Vatslava Havela Boulevard, Kyiv, 03124, Tel/Fax: +38 044 281 2333.