Betahistine Dihydrochloride

Betahistine Dihydrochloride is used to prevent and treat a disorder of the inner ear known as Meniere's disease. The symptoms include dizziness (vertigo), ringing in the ears (tinnitus) and loss of hearing, probably caused by fluid in the ear. This medicine helps relieve the symptoms by reducing the amount of fluid.

Betahistine mainly acts as a histamine H1-receptor agonist. 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. It also acts as a histamine H3-receptor antagonist, increasing histamine turnover and reducing the activity of vestibular nuclei, which helps restore balance and decrease vertigo symptoms.

Common side effects include headache, nausea, and indigestion. Taking the medicine with food can help reduce stomach problems.

• Meniere's disease
• Meniere-like syndromes (vertigo, tinnitus, hearing loss)

The mechanism of action of betahistine is multifactorial. Meniere'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 Meniere's disease. Betahistine also acts by reducing the asymmetrical functioning of sensory vestibular organs and increasing vestibulocochlear blood flow, relieving symptoms of vertigo.

In addition, 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.

Betahistine improves the microcirculation in the labyrinth which reduces endolymphatic pressure and relieves vertigo symptoms. It acts as an H1-receptor agonist and H3-receptor antagonist, regulating fluid pressure in the ear and reducing signals sent to the brain.

Adults:

• Initial dose: 8-16 mg three times daily (preferably with meals)
• Maintenance dose: 24-48 mg daily (maximum 48 mg/day)
• Dosage can be adjusted according to individual needs

Children and adolescents (under 18 years): Not recommended due to lack of safety and efficacy data.

Swallow the tablet whole, do not chew or crush. Take with food to reduce stomach upset. Take at the same time(s) each day.

If you miss a dose, skip it and continue with your normal schedule. Do not double the dose.

• Headache
• Nausea
• Dyspepsia
• Stomach pain and bloating
• Skin rash and pruritus (rare)

• Caution in patients with peptic ulcer or a history of ulceration
• Caution in patients with bronchial asthma
• Caution in patients with urticaria, rashes, or allergic rhinitis
• Caution in patients with severe hypotension
• Patients with galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption should not take this medicine
• Caution during pregnancy and lactation
• May cause drowsiness; avoid driving or operating machinery if affected

• Phaeochromocytoma
• Porphyria
• Hypersensitivity to betahistine or any component

• Antihistamines: Betahistine may antagonize the effects of antihistamines
• Beta-2 agonists: Betahistine may decrease bronchodilator effects
• Salbutamol: May potentiate betahistine effects (rare)

[SAFE] Consuming alcohol with Betahistine Dihydrochloride does not cause any harmful side effects.

[CONSULT YOUR DOCTOR] The safety of betahistine in human pregnancy has not been completely established. Animal studies have shown no teratogenic effects. Use only if potential benefit justifies the potential risk.

[CONSULT YOUR DOCTOR] Betahistine is excreted in breast milk (in concentrations similar to plasma). The toxicity to the neonate is unknown. Caution is advised.

Not recommended for use in children and adolescents below age 18 due to lack of data on safety and efficacy.

Limited data in the elderly; betahistine should be used with caution.

[SAFE IF PRESCRIBED] Limited data suggests dose adjustment may not be needed in kidney disease. Consult your doctor.

[CONSULT YOUR DOCTOR] Limited information available on use in liver disease. Consult your doctor.

Symptoms: Nausea, vomiting, dyspepsia, ataxia, and seizures. In severe cases (intentional overdose), convulsions, pulmonary or cardiac complications may occur.

Treatment: No specific antidote. Gastric lavage and symptomatic treatment are recommended.

Keep below 30°C, away from light and moisture. Keep out of reach of children.

Betahistine Dihydrochloride (C₈H₁₆N₂·2HCl)