Betahistine 24 mg 30 tablets

Indications

Treatment of Meniere's syndrome, characterized by dizziness (accompanied by nausea and vomiting), hearing loss, and tinnitus. Symptomatic treatment of vestibular vertigo.

Section: Method of administration and doses

Take orally, during meals, without chewing, with a small amount of liquid, 1 tablet (24 mg) twice a day. The treatment is long-term; improvement is sometimes observed after several weeks, and the best results in some cases are achieved after several months of treatment. The course of treatment is determined individually.
Dose adjustment in elderly patients is not required. Special studies in patients with renal/hepatic insufficiency have not been conducted; however, post-marketing experience suggests that dose adjustment in this category of patients is not necessary.

Section: Composition

Each tablet contains the active substance:
betahistine dihydrochloride - 24.0 mg.
Excipients: microcrystalline cellulose - 199.5 mg; corn starch - 30.0 mg; copovidone - 27.0 mg; sodium carboxymethyl starch - 15.0 mg; magnesium stearate - 3.0 mg; colloidal silicon dioxide - 1.5 mg.

Description of the dosage form

Round flat-cylindrical tablets of white or almost white color with a light brown tint, with a bevel and a score.

Contraindications

Hypersensitivity to the components of the medicinal product, pregnancy, breastfeeding period, age under 18 years (due to lack of data), pheochromocytoma, lactose intolerance, lactase deficiency, glucose-galactose malabsorption.

With caution

Peptic ulcer disease of the stomach or duodenum (in history), bronchial asthma. Use during pregnancy and breastfeeding

Insufficient data to assess the impact of the drug during pregnancy and breastfeeding. Therefore, the drug is contraindicated during pregnancy. During treatment, breastfeeding should be discontinued.

Special instructions

Therapeutic effect in some cases increases over several months from the start of treatment.

Impact on the ability to drive vehicles and operate machinery

The impact on the ability to drive vehicles and operate machinery is absent or negligible.

Section: Side Effects

The frequency of side effects was determined according to the following grading of the occurrence of side effects: very common (≥1/10); common (≥1/100,

Section: Overdose

Symptoms: nausea, vomiting, headache, facial skin hyperemia, dizziness, tachycardia, decreased blood pressure, bronchospasm; drowsiness (when taken in a dose up to 640 mg); seizures, cardiopulmonary complications (when taken in a dose greater than 640 mg or in combination with other medications).
Treatment: gastric lavage, activated charcoal intake, symptomatic.

Interaction

Antihistamine medications reduce the effect of betahistine. The interaction of betahistine with H ^histamine blockers and new receptors when used simultaneously may theoretically affect the effectiveness of one of these agents. Cases of interaction or incompatibility with other medications are unknown. Based on in vitro data, it can be assumed that there is no inhibition of the activity of cytochrome P450 isoenzymes in vivo. In vitro data showed inhibition of betahistine metabolism by drugs that inhibit monoamine oxidase (MAO), including MAO subtype B (e.g., selegiline).

Pharmacodynamics

Agonist of H1-histamine receptors in the blood vessels of the inner ear and antagonist of H3-histamine receptors in the vestibular nuclei of the central nervous system (CNS). By relaxing the precapillary sphincters of the blood vessels in the inner ear, it improves blood circulation in the vascular strip of the inner ear. It enhances blood flow in the brain, dose-dependently reduces the generation of action potentials in the neurons of the lateral and medial vestibular nuclei. It accelerates the recovery of vestibular function after unilateral vestibular neurectomy, facilitating and speeding up central vestibular compensation (due to antagonism with H3-histamine receptors). It alleviates symptoms in Meniere's syndrome and vertigo.

Section: Pharmacokinetics

Rapidly and almost completely absorbed in the gastrointestinal tract. When taken with food, the maximum concentration of betahistine in the blood is lower than when taken on an empty stomach. However, the total absorption is the same in both cases, indicating that food intake slows down absorption. Absorbed quickly, with plasma protein binding of less than 5%. Time to reach maximum concentration in plasma is 1 hour.
Metabolized to inactive metabolites: 2-pyridylacetic acid (the main metabolite) and dimethylbetahistine. The maximum concentration of 2-pyridylacetic acid in plasma (or urine) is reached one hour after administration. The half-life is approximately 3.5 hours. 85-90% is excreted by the kidneys as 2-pyridylacetic acid within 24 hours. The excretion of betahistine and dimethylbetahistine by the kidneys is negligible. Only a small portion (about 10%) of betahistine and its metabolites is excreted by the intestines. The rate of excretion remains constant, indicating linear pharmacokinetics.