Instructions for use Vestinorm tablets 16 mg blister No. 60
Composition
active ingredient: betahistine;
1 tablet contains betahistine dihydrochloride 8 mg or 16 mg or 24 mg calculated on 100% dry matter;
Excipients: microcrystalline cellulose, sodium starch glycolate (type A), colloidal anhydrous silica, povidone, magnesium stearate.
Dosage form
Pills.
Main physicochemical properties: round tablets with a flat surface with a score and a bevel, white or almost white in color. Marbling is allowed on the surface of the tablets (for tablets of 8 mg and 16 mg).
Pharmacotherapeutic group
Treatments for vestibular disorders.
ATX code N07C A01.
Pharmacological properties
Pharmacodynamics
The mechanism of action of betahistine is only partially understood. There are several plausible hypotheses that have been supported by animal and human studies.
The effect of betahistine on the histaminergic system.
Betahistine has been shown to have partial agonist activity at H1 receptors and antagonist activity at histamine H3 receptors in nervous tissue, with little activity at histamine H2 receptors. Betahistine increases histamine metabolism and release by blocking presynaptic H3 receptors and inducing a process of downregulation of the corresponding H3 receptors.
Betahistine can increase blood flow in the cochlear area, as well as throughout the brain.
Pharmacological studies in animals have shown an improvement in blood flow in the stria vascularis of the inner ear, possibly by relaxing precapillary sphincters in the inner ear microcirculation system. Betahistine has also been shown to increase cerebral blood flow in humans.
Betahistine promotes vestibular compensation.
Betahistine accelerates the recovery of vestibular function after unilateral neurectomy in animals by stimulating and promoting the process of central vestibular compensation. This effect is characterized by increased regulation of histamine metabolism and release and is realized as a result of H3-receptor antagonism. In humans, treatment with betahistine also reduced the time to recovery of vestibular function after neurectomy.
Betahistine alters the activity of neurons in the vestibular nuclei.
It was also found that betahistine has a dose-dependent inhibitory effect on the generation of spike potentials in neurons of the lateral and medial vestibular nuclei.
The pharmacodynamic properties of betahistine, as shown in animals, may provide a positive therapeutic effect of the drug in the vestibular system.
The effectiveness of betahistine has been shown in studies in patients with vestibular vertigo and Ménière's disease, as demonstrated by a reduction in the severity and frequency of vertigo attacks.
Pharmacokinetics
Absorption.
When administered orally, betahistine is rapidly and almost completely absorbed from all parts of the gastrointestinal tract. After absorption, the drug is rapidly and almost completely metabolized to form the metabolite 2-pyridylacetic acid. The concentration of betahistine in blood plasma is very low. Therefore, all pharmacokinetic analyses are carried out by measuring the concentration of the metabolite 2-pyridylacetic acid in plasma and urine.
When the drug is taken with food, the maximum concentration (Cmax) of the drug is lower than when taken on an empty stomach. At the same time, the complete absorption of betahistine is identical in both cases, which indicates that food intake only slows down the absorption process of the drug.
Distribution.
The percentage of betahistine bound to blood plasma proteins is less than 5%.
Biotransformation.
After absorption, betahistine is rapidly and almost completely metabolized to 2-pyridylacetic acid (which has no pharmacological activity).
After oral administration of betahistine, the concentration of 2-pyridylacetic acid in blood plasma (and urine) reaches its maximum 1 hour after administration and decreases with a half-life of about 3.5 hours.
Breeding.
2-pyridylacetic acid is rapidly excreted in the urine. When taking the drug in a dosage of 8-48 mg, about 85% of the initial dose is found in the urine. The excretion of betahistine by the kidneys or with feces is insignificant.
Linearity.
The recovery rate remains constant over the oral administration of 8-48 mg of the drug, indicating linearity of betahistine pharmacokinetics and suggesting that the metabolic pathway involved is non-saturable.
Indication
Meniere's disease and syndrome, which are characterized by three main symptoms:
– dizziness, sometimes accompanied by nausea and vomiting;
– hearing loss (hearing loss);
– tinnitus.
Symptomatic treatment of vestibular vertigo of various origins.
Contraindication
Hypersensitivity to any of the components of the drug.
Pheochromocytoma.
Interaction with other medicinal products and other types of interactions
In vitro data indicate that betahistine metabolism is inhibited by drugs that inhibit monoamine oxidase (MAO) activity, including MAO subtype B (e.g. selegiline). Caution is recommended when betahistine is used concomitantly with MAO inhibitors (including selective MAO subtype B).
Since betahistine is a histamine analogue, the interaction of betahistine with antihistamines could theoretically affect the effectiveness of one of these drugs.
Application features
During treatment with the drug, it is necessary to carefully monitor the condition of patients with bronchial asthma and/or a history of gastric and duodenal ulcers.
It is recommended to use with caution for the treatment of patients with peptic ulcer disease (including a history), since cases of dyspepsia occasionally occur in patients taking betahistine.
Betahistine should be prescribed with caution to patients with existing urticaria, rash or allergic rhinitis, as these symptoms may worsen.
The drug should be prescribed with caution to patients with severe hypotension.
Use during pregnancy or breastfeeding
Pregnancy: There are no adequate data from the use of betahistine in pregnant women.
Animal studies are insufficient to assess direct or indirect effects on pregnancy, embryonal/fetal development, parturition and postnatal development. The potential risk to humans is unknown. Betahistine should not be used during pregnancy unless clearly necessary.
Breastfeeding. It is not known whether betahistine is excreted in human breast milk. Animal studies on the excretion of betahistine in milk have not been conducted. Betahistine should not be used during breastfeeding.
Ability to influence reaction speed when driving vehicles or other mechanisms
Dizziness, hearing loss, tinnitus associated with Ménière's syndrome may adversely affect the ability to drive or operate machinery. Betahistine, according to clinical studies, does not have a significant effect or effects that potentially affect the ability to drive or operate machinery.
Method of administration and doses
The daily dose for adults is 24–48 mg, evenly distributed throughout the day.
| 8 mg tablets | 16 mg tablets | 24 mg tablets |
1–2 tablets 3 times a day | ½–1 tablet 3 times a day | 1 tablet 2 times a day |
The dose should be adjusted individually, depending on the effect. A reduction in symptoms is sometimes observed only after 2-3 weeks of treatment. The best results are sometimes achieved when taking the drug for several months. There is evidence that prescribing treatment early in the disease prevents its progression and/or hearing loss in the later stages.
Elderly patients
Although clinical trial data in this patient group are currently limited, extensive post-marketing experience suggests that dose adjustment is not necessary for this patient group.
Kidney failure
No specific clinical trials have been conducted in this patient group, but based on post-marketing experience, no dose adjustment is required.
Liver failure
No specific clinical trials have been conducted in this patient group, but based on post-marketing experience, no dose adjustment is required.
Children
Due to insufficient data on the safety and efficacy of the drug Vestinorm®, it is not recommended for use in children (under 18 years of age).
Overdose
Several cases of overdose of the drug are known. Some patients experienced mild to moderate symptoms when taking a dose of up to 640 mg (nausea, drowsiness, abdominal pain). Other symptoms of overdose were vomiting, dyspepsia, ataxia and convulsions. More serious complications (convulsions, cardiac and pulmonary complications) were observed with intentional administration of increased doses of betahistine, especially with simultaneous overdose with other drugs.
Treatment: gastric lavage and symptomatic therapy are recommended within one hour after taking the drug.
Adverse reactions
Gastrointestinal: nausea and dyspepsia, complaints of minor stomach upset (vomiting, gastrointestinal pain, bloating and flatulence). These side effects usually disappear when the drug is taken with food or after reducing the dose.
From the nervous system: headache.
Immune system disorders: Hypersensitivity reactions, e.g. anaphylaxis.
Skin and subcutaneous tissue disorders: hypersensitivity reactions of the skin and subcutaneous fat, including angioedema, rash, itching and urticaria.
Expiration date
3 years.
Do not use the drug after the expiration date indicated on the package.
Storage conditions
Store in a place protected from light at a temperature not exceeding 25 ºС.
Keep out of reach of children.
Packaging
10 tablets in a blister. 8 mg tablets. 3 blisters in a pack.
Tablets of 16 mg and 24 mg. 3 or 6 blisters in a pack.
Vacation category
According to the recipe.
Producer
JSC "Farmak".
Location of the manufacturer and its business address
Ukraine, 04080, Kyiv, Kyrylivska St., 74.
