Description
Betacerc Pharmacodynamics
The mechanism of action of betahistine is only partially known. There are several possible hypotheses supported by preclinical and clinical data:
-Influence on the histaminergic system
Partial agonist of H1-histamine and antagonist of H3-histamine receptors of the vestibular nuclei of the CNS, has negligible activity against H2 receptors. Betahistine increases histamine metabolism and release by blocking presynaptic H3 receptors and decreasing H3 receptors.
-Enhancement of cochlear blood flow as well as the entire brain
According to preclinical studies, betahistine improves blood flow in the inner ear vasculature by relaxing the precapillary sphincters of the inner ear vessels. Betahistine has also been shown to increase cerebral blood flow in humans.
-Enhancement of central vestibular compensation
Betahistine accelerates the recovery of vestibular function in animals after unilateral vestibular neurectomy by accelerating and facilitating central vestibular compensation through antagonism with H3-histamine receptors.
Recovery time after vestibular neurectomy in humans is also reduced by treatment with betahistine.
-Activation of neurons in the vestibular nuclei
Dose-dependently reduces the generation of action potentials in neurons of the lateral and medial vestibular nuclei.
The pharmacodynamic properties found in animals provide a positive therapeutic effect of betahistine in the vestibular system.
The efficacy of betahistine has been demonstrated in patients with vestibular vertigo and Meniere’s syndrome, as manifested by a reduction in the severity and frequency of vertigo.
Indications
Meniere’s syndrome, characterized by the following main symptoms:
– Dizziness (accompanied by nausea/vomiting)
– Decreased hearing (hearing loss)
– tinnitus
Symptomatic treatment of vestibular vertigo
Contraindications
– pheochromocytoma;
– Hypersensitivity to any component of the drug.
Betaserk® is not recommended for use in children under 18 years of age because of insufficient data on efficacy and safety.
Caution
Patients with bronchial asthma, peptic ulcer and/or duodenal ulcer require close supervision during treatment.
Administration in pregnancy and during breast-feeding
Pregnancy
There are insufficient data available on the use of betahistine in pregnant women.
Animal studies have shown no direct or indirect reproductive toxicity.
Betahistine should not be used during pregnancy except when clearly necessary.
Breastfeeding.
It is not known whether betahistine is excreted with breast milk in humans. Betahistine is excreted with breast milk in rats. Animal studies have been limited to the use of the drug at very high doses. Administration of the drug to the mother should be decided only after weighing the benefits of breastfeeding against the potential risks to the infant.
Fertility
No effect on fertility has been found in animal studies (rats).
Dosage and administration
- Always take Betaserk® exactly as prescribed by your doctor. If you have any questions, consult your doctor.
- Orally, with meals.
- The adult dose of betahistine is 24-48 mg per day.
- Betacerc® 16 mg should be taken ? – 1 tablet 3 times daily. The tablet can be divided into two equal parts.
- Place the tablet on a hard surface with the rib upwards and press it down with your thumb.
- The dose should be adjusted individually, depending on how you react to the treatment.
- Improvement is sometimes seen after several weeks of treatment. The best results are sometimes seen after several months of treatment. There is evidence that early treatment prevents progression of the disease and/or hearing loss in later stages.
- Older age
Although clinical trial data are limited, extensive post-registration experience suggests that dose adjustments are not necessary in this group of patients. - Patients with renal/hepatic impairment
No special clinical studies have been conducted in this group of patients, but post-registration experience suggests that no dose adjustment is required in this patient group.
