Maxgistin

Maxhistin is a medication used to treat various vestibular disorders.

Indications Maxgistin

Indications for use of the drug include:

• Meniere's disease, which is characterized by 3 main symptoms - dizziness (in some cases with vomiting and nausea), hearing loss, and the appearance of tinnitus;
• symptomatic therapy to eliminate vestibular vertigo of various origins.

Release form

Available in tablet form. One blister contains 10 tablets. The package contains 3 or 6 blister strips.

Pharmacodynamics

The mechanism of action of the active component of the drug (betahistine) on the body is poorly understood. Among the most reliable hypotheses are the following:

The effect of the active substance on the histaminergic structure: it has partial internal activity in relation to H1 receptors, and in addition, it acts as an antagonist of histamine receptors (H3) inside the nerve tissues and has a weak effect on H2-histamine receptors. In addition, betahistine increases the rate of metabolism and release of this component, blocking H3 receptors (presynaptic) - thereby inducing a decrease in their number.

Betahistine increases blood flow to the cochlear region and brain – the blood circulation process in the vessels located in the inner ear (stria vascularis) improves – due to the weakening of tension in the precapillary sphincters involved in the microcirculation process in the inner ear. In addition, the active substance helps to accelerate the intensity of cerebral blood flow.

Betahistine stimulates vestibular compensation – increases the rate of recovery of vestibular apparatus activity in animals with unilateral neurectomy. The substance achieves this effect by improving the regulation of histamine release and metabolism processes, and also acting as an antagonist of H3 receptors. When treating with this drug after neurectomy in humans, the period of recovery of vestibular apparatus functionality is also reduced.

Betahistine affects neuronal activity within the vestibular nuclei – depending on the dosage, it slows down the formation of their peak potentials within the medial and lateral nuclei.

Pharmacokinetics

After internal use, betahistine is almost completely and fairly quickly absorbed from the gastrointestinal tract. The drug then quickly undergoes a metabolic process, resulting in the formation of pyridyl-2-acetic acid, which is a decay product. The accumulation rates of betahistine in blood plasma are very low, which is why all pharmacokinetic tests are performed by determining the concentration level of its decay product in urine.

When the drug is taken with food, the peak concentration indicator is lower than when taken on an empty stomach. However, the complete absorption of the active substance is the same in both situations – this is a sign that food only slows down the absorption process.

Less than 5% of betahistine is bound to plasma proteins.

Almost all absorbed betahistine is converted into pyridyl-2-acetic acid (which has no pharmacological activity). The internal accumulation of this metabolite in urine and blood plasma reaches its peak 1 hour after taking the drug. This indicator decreases with a half-life of approximately 3.5 hours.

Pyridyl-2-acetic acid is excreted in urine. After taking the drug in a dosage of 8-48 mg, approximately 85% of the substance is determined in urine. The active component is excreted in small quantities through the kidneys or with feces.

The elimination rate does not change with drug dosage, indicating that betahistine pharmacokinetics are linear. This allows the metabolic pathway used to be considered non-saturable.

Dosing and administration

You need to take 24-48 mg of the medicine per day (the dose should be divided into several doses). Tablets of 8 mg should be taken 1-2 at a time three times a day. Tablets of 16 mg should be taken 0.5-1 piece also three times a day. Tablets of 24 mg should be taken twice a day, 1 piece at a time.

It is recommended to take the medicine after meals, and the dosage should be selected individually for each patient, in accordance with the effect obtained.

In some cases, symptoms begin to ease only after 2-3 weeks of therapy. Sometimes the desired effect can be achieved only after several months of taking the drug. There is information that when prescribing therapy at the initial stages of the disease, it is possible to prevent its progression or hearing loss at a later stage.

Use Maxgistin during pregnancy

Since there is no necessary information about the use of the drug during pregnancy, it is not recommended to use it during this period. The only exceptions are cases of urgent need.

Contraindications

Among the contraindications:

• the presence of individual intolerance to the elements of the drug;
• pheochromocytoma.

Side effects Maxgistin

Side effects from taking Maxhistin include:

• Digestive system organs: dyspeptic symptoms and nausea, minor symptoms of stomach upset (flatulence, as well as vomiting and gastrointestinal syndrome). All these symptoms usually disappear after reducing the dosage or taking the drug with food;
• nervous system organs: occurrence of headaches;
• immune system: hypersensitivity in the form of anaphylaxis, etc.;
• skin and subcutaneous tissue: allergic reactions to the fatty tissue under the skin, as well as the skin, such as rashes, urticaria, itching, or Quincke's edema.

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Overdose

There are several cases of Maxhistine overdose - when using the drug in a dosage of up to 640 mg. In this case, patients showed moderate or mild symptoms - such as drowsiness, nausea and abdominal pain. More dangerous complications (such as seizures, development of cardiopulmonary disorders) developed in the case of intentional use of betahistine in high doses (especially when combined with an overdose of other drugs).

To eliminate the disorders, supportive and symptomatic treatment is prescribed.

Interactions with other drugs

Information obtained from in vitro studies shows that the metabolic processes of the active substance Maxhistin are suppressed when combined with drugs that inhibit MAO activity (selegiline, which belongs to the MAO subtype B category, is among such elements). Therefore, these drugs should be combined with caution during treatment.

Since betahistine is an analogue of the substance histamine, in the event of interaction of this component with antihistamine drugs, in theory it may affect the effectiveness of any of these drugs.

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Storage conditions

The medicine should be kept in standard conditions, inaccessible to children. The temperature should not exceed 25°C.

Shelf life

Maxhistine is permitted to be used for 2 years from the date of manufacture of the drug.