Vestinorm

General characteristics. Structure:

Active ingredient: betahistine;

1 tablet contains a betagistin of dihydrochloride of 8 mg or 16 mg, or 24 mg in terms of 100% dry matter;

excipients: cellulose microcrystallic, sodium krakhmalglikolit (type A), silicon dioxide colloid anhydrous, povidone, magnesium stearate.

Pharmacological properties:

Pharmacodynamics. The mechanism of action of a betagistin is studied only partially. There are several reliable hypotheses confirming data of researches on animals and with the assistance of people.

Influence of a betagistin on gistaminergichesky system: it is established what бетагистин partially shows antagonistic activity concerning H1 receptors, and also antagonistic activity histamine H3 receptors in nervous tissue are relative and show insignificant activity concerning histamine H2 receptors. Betagistin increases exchange and release of a histamine by blocking of presynaptic  H3 receptors and the induction of process of decrease in quantity corresponding to H3 receptors.

Betagistin can increase a blood stream in a cochlear zone, and also in all brain: pharmacological researches on animals showed improvement of blood circulation in vessels of stria vascularis of an inner ear, perhaps, due to relaxation of precapillary sphincters in system of microcirculation of an inner ear. Betagistin also showed increase in a brain blood-groove at the person.

Betagistin promotes vestibular compensation: бетагистин accelerates recovery of vestibular function after a unilateral neurectomy at animals, accelerating and promoting the central vestibular compensation. This effect is characterized by strengthening of regulation of exchange and release of a histamine and is implemented as a result of antagonism of H3 receptors. At people during treatment betagistiny time of recovery of vestibular function after a neurectomy also decreased.

Betagistin changes activity of neurons in vestibular nuclei: it was also established what бетагистин has the dozozavisimy inhibiting influence on generation of spike potentials in neurons of lateral and medial vestibular nuclei.

Pharmakodinamichesky properties of a betagistin as it was shown on animals, can provide positive therapeutic effect of drug in vestibular system.

Efficiency of a betagistin was shown by researches with participation of patients with vestibular dizziness and Menyer's disease during which reduction of weight and frequency of attacks of dizziness was observed.

Pharmacokinetics. Absorption

At peroral introduction бетагистин it is quickly and almost completely soaked up in a digestive tract. After absorption drug quickly and almost is completely metabolized with formation of a metabolite of 2-pyridylacetic acid. Level of concentration of a betagistin in a blood plasma very low.

Therefore all pharmacokinetic analyses are carried out by measurement of concentration of a metabolite of 2-pyridylacetic acid in a blood plasma and urine.

At administration of drug with food its maximum concentration (Cmax) is lower, than at reception on an empty stomach. At the same time full absorption of a betagistin is identical in both cases that indicates that meal only slows down drug absorption.

Distribution

The percent of a betagistin which contacts proteins of a blood plasma makes less than 5%.

Biotransformation

After absorption бетагистин quickly and almost it is completely metabolized in 2-pyridylacetic acid (which does not show pharmacological activity).

After reception of a betagistin inside concentration of 2-pyridylacetic acid in a blood plasma (and in urine) reaches the maximum in 1 hour after administration of drug and decreases with an elimination half-life about 3,5 hours.

Removal

2-pyridylacetic acid is quickly removed with urine. At administration of drug in a dosage of 8-48 mg about 85% of an initial dose are found in urine. Removal of a betagistin kidneys or with a stake is insignificant.

Linearity

The recovery rate remains to a constant at oral administration of 8-48 mg of drug that indicates linearity of pharmacokinetics of a betagistin and allows to assume that the involved metabolic way remains not intensive.

Pharmaceutical characteristics.

Main physical and chemical properties: tablets of a round form with a flat surface with risky and a facet, white or almost white color. On a surface of tablets the mramornost is allowed (for tablets on 8 mg and 16 mg).

Indications to use:

Disease and Menyer's syndrome which are characterized by such main symptoms as the dizziness which is followed sometimes by nausea and vomiting, decrease in hearing (relative deafness), a sonitus.

Symptomatic treatment of vestibular dizziness.

Route of administration and doses:

Appoint the adult inside. The daily dose makes 24-48 mg, evenly distributed for reception for days.

Tablets on 8 mg
 
Tablets on 16 mg
 
Tablets on 24 mg

1-2 tablets 3 times a day
 
½-1 a tablet 3 times a day
 
1 tablet 2 times a day

Pill is taken after food, without chewing.

The dose and duration of therapy are defined by the doctor individually depending on efficiency of therapy. Reduction of symptoms is sometimes observed only after 2-3 weeks of treatment. The best results are observed at administration of drug for several months. If to appoint treatment at the beginning of a disease, it is possible to prevent progressing it and/or a hearing loss at late stages.

Patients of advanced age

Dose adjustment for patients of this group is not required.

Renal failure

Dose adjustment is not required.

Liver failure

Dose adjustment is not required.

Features of use:

Use during pregnancy or feeding by a breast.

There are no data on use of a betagistin by pregnant women. Drug can be accepted only in urgent cases and under direct observation of the doctor.

Penetration of a betagistin into breast milk was not studied. The advantage of use of drug is determined by a ratio of advantage of feeding by a breast / potential risk for the child.
Children.

Experience of use of drug for treatment of children is absent therefore this age category should not appoint it.

Patients with bronchial asthma, a peptic ulcer of a stomach and duodenum in the anamnesis demand careful medical observation during treatment by Vestinorm.
Ability to influence speed of response at control of motor transport or work with other mechanisms.

Betagistin according to data of clinical trials, does not exert considerable impact or effects which potentially influence ability to drive the car or to work with other mechanisms.

Side effects:

From a digestive tract: often – nausea, dyspepsia; frequency is unknown – complaints to insignificant gastric disturbances (vomiting, an abdominal pain, abdominal distention and a meteorism). These side effects usually disappear at administration of drug with food or after reduction of a dose.  

From a nervous system: often – a headache.

From immune system: frequency is unknown – hypersensitivity reactions, for example an anaphylaxis.

From skin and hypodermic cellulose: frequency is unknown – reactions of hypersensitivity of skin and a hypodermic fatty tissue, in particular a Quincke's disease, rash, an itch and a small tortoiseshell were observed.

Interaction with other medicines:

On the basis of data of the research in vitro oppression of activity of enzymes of P450 in vivo cytochrome is not expected.

The data obtained in the conditions of in vitro confirm oppression of metabolism of a betagistin drugs which inhibit activity of a monoaminooxidase (MAO), including the B MAO subtype (for example селегилин). It is recommended to be careful at simultaneous use of a betagistin and MAO inhibitors (including selectively B MAO subtype).

As бетагистин is a histamine analog, interaction of a betagistin with antihistaminic drugs can theoretically affect efficiency of one of these drugs.

Contraindications:

Hypersensitivity to active ingredient and to other components of drug. Pheochromocytoma.

Overdose:

At overdose nausea, an abdominal pain, drowsiness can be observed. Messages on emergence of spasms and cardiopulmonary complications at intended reception of the raised doses of a betagistin were, especially in combination with overdose other drugs.

Treatment: symptomatic therapy.

Storage conditions:

Period of validity. 3 years. Not to use drug after the termination of the period of validity specified on packaging. To store in the place protected from light at a temperature not over 25 ºС. To store in the place, unavailable to children.

Issue conditions:

According to the recipe

Packaging:

On 10 tablets in the blister. Tablets on 8 mg. On 3 blisters in a pack.

Tablets on 16 mg and 24 mg. On 3 or 6 blisters in a pack.