Vetahist G

Vetahist G Uses, Dosage, Side Effects, Food Interaction and all others data.

The mechanism of action of betahistine is known partially. Betahistine has a very strong affinity as an antagonist for histamine H3 receptors and a weak affinity as an agonist for histamine H1 receptors. The active ingredient is a specific histamine agonist with virtually no H2-activity.

Betahistine has two modes of action. Primarily, it has a direct stimulating (agonistic) effect on H1 receptors located on blood vessels in the inner ear. It appears to act on the precapillary sphincter in the stria vascularis of the inner ear, thus reducing the pressure in the endolymphatic space.

In addition, betahistine has a powerful antagonistic effects at H3 receptors, and increases the levels of neurotransmitters released from the nerve endings. The increased amounts of histamine released from histaminergic nerve endings stimulates H1 receptors, thus augmenting the direct agonistic effects of betahistine on these receptors. This explains the potent vasodilatory effects of betahistine in the inner ear. This explains the efficacy of betahistine in the treatment of vertigo.

Through its actions on the histamine receptors, betahistine provides relief from vertigo associated with Ménière's disease.

Vetahist G
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	Vetahist G
Generic	Betahistine + Gingko Biloba
Weight	24mg
Type	Tablet
Therapeutic Class
Manufacturer	Mova Pharmaceuticals Pvt Ltd
Available Country	India
Last Updated:	September 19, 2023 at 7:00 am

Uses

Betahistine Mesilate dilates precapiilary sphincters, increasing the blood flow in the inner ear. It controls the permeability of capillaries in the inner ear, thereby removes endolymphatic hydrops. It also improves cerebral circulation, increasing blood flow in the internal carotid artery. Thus, Betahistine Mesylate is clinically useful for the relief of vertigo and dizziness.

Vetahist G is also used to associated treatment for these conditions: Menière's Disease

How Vetahist G works

Vertigo is a disturbing sensation of movement caused by dysfunction of the labyrinth (inner ear), vestibular nerve, cerebellum, brainstem, or Central Nervous System (CNS). Vestibular forms of vertigo are often accompanied by auditory dysfunctions such as hyperacusis, hearing loss, and tinnitus. In most cases, adaptive mechanisms of the CNS lead to functional recovery after episodes of vertigo, however, syndromes such as Ménière's disease tend to cause the recurrence of vertigo symptoms. This significantly impacts the quality of life and the ability to carry out daily activities.

H1-receptor activity

The mechanism of action of betahistine is multifactorial. Ménière's disease is thought to result from a disruption of endolymphatic fluid homeostasis in the ear. Betahistine mainly acts as a histamine H1-receptor agonist. The stimulation of H1-receptors in the inner ear causes a vasodilatory effect leading to increased permeability of blood vessels and a reduction in endolymphatic pressure; this action prevents the rupture of the labyrinth, which can contribute to the hearing loss associated with Ménière's disease. Betahistine is also purported to act by reducing the asymmetrical functioning of sensory vestibular organs and increasing vestibulocochlear blood flow, relieving symptoms of vertigo.

H3-receptor activity

In addition to the above mechanisms, betahistine also acts as a histamine H3-receptor antagonist, increasing the turnover of histamine from postsynaptic histaminergic nerve receptors, subsequently leading to an increase in H1-agonist activity. H3-receptor antagonism elevates levels of neurotransmitters including serotonin in the brainstem, inhibiting the activity of vestibular nuclei, thus restoring proper balance and decreasing vertigo symptoms.

Dosage

Vetahist G dosage

Usually for adults, administer orally 6 mg to 12 mg three times per day after meals. The dose may be adjusted according to the age of patient and severity of symptoms.

Side Effects

Nausea or vomiting may rarely occur. Hypersensitivity reactions, such as skin rash, may rarely occur.

Toxicity

Symptoms of an overdose with betahistine (< 640 mg) include dry mouth, nausea, dyspepsia, abdominal pain, and somnolence. Serious complications such as convulsions, pulmonary or cardiac effects may occur with higher doses (> 640 mg), especially during intentional overdoses and combination with other drugs. In the case of an overdose with betahistine, provide supportive therapy, and contact the local poison control center for further management.

Precaution

Patients with a history of digestive ulcer or an active digestive ulcer, Patients with bronchial asthma, Patients with pheochromocytoma.

Volume of Distribution

In a pharmacokinetic study of rats, betahistine was found to be distributed throughout the body. Human data for betahistine's volume of distribution is not readily available.

Elimination Route

When given orally, betahistine is rapidly and almost completely absorbed from the gastrointestinal tract. In the fasted state, Cmax is achieved within 1 hour of administration; in the fed state, Cmax is delayed, but the total drug absorption is similar. Food, therefore, has little effect on the absorption of betahistine.

Half Life

The half-life of betahistine is 3-4 hours.

Elimination Route

Betahistine is mainly excreted in the urine; with approximately 85-91% being detected in urine samples within 24 hours of administration.

Pregnancy & Breastfeeding use

Safety of Betahistine during pregnancy has not been established. This drug should be administered to pregnant patients or women suspected of being pregnant, only if the expected therapeutic benefit is thought to outweigh any possible risk.