Irbetan

Irbetan is a medication that has an antihypertensive effect. When used, there is a weakening of systemic peripheral vascular resistance, and in addition, a decrease in the total values of blood pressure, pressure within the small circle of blood flow and cardiac afterload.

The development of the maximum activity of the drug develops after 3-6 hours from the moment of administration, and the therapeutic effect lasts for a period of 24 hours. To achieve a stable clinical effect, it is necessary to take the drug for a period of 1-2 weeks. [1]

Indications Irbetan

It is used for diseases such as primary hypertension and increased blood pressure in people with renal pathologies.

It can also be prescribed in combination for antihypertensive therapy of type 2 diabetes mellitus .

Release form

The release of the therapeutic substance is realized in tablets - 10 pieces inside the cell pack; inside the box - 2 such packs.

Pharmacodynamics

Irbesartan, when taken orally, acts as a selective antagonist of the endings of angiotensin-2 (AT1) with a powerful active influence. The component is able to block any effects of angiotensin-2, which are mediated by the end of AO1, regardless of the method or source of binding of angiotensin-2.

Selective antagonism of the endings of angiotensin-2 (AT1) causes an increase in the indices of renin with angiotensin-2 inside the blood plasma, as well as a decrease in the plasma values of aldosterone. [2]

At the serum potassium level, irbesartan itself does not have a significant effect (with the introduction of the recommended dosages). The substance does not slow down under the influence of ACE (kininase-2), an enzyme that catalyzes the formation of angiotensin-2, as well as the degradation of bradykinin to a state of metabolic elements that do not have a therapeutic effect. Irbesartan is active without metabolic stimulation. [3]

Pharmacokinetics

Ingested irbesartan is well absorbed, with bioavailability in the range of 60-80%. Eating with food does not alter the bioavailability of the drug.

Intraplasmic protein synthesis of irbesartan is approximately 96%, but the synthesis with cellular blood elements is very weak. The distribution volume of the drug is in the range of 53-93 liters.

When ingested or intravenously administered 14C-irbesartan, from radioactive particles circulating inside the blood plasma, 80-85% is unchanged irbesartan.

Intrahepatic metabolic processes occur through oxidation and glucuronide conjugation. Glucuronide is the main circulating metabolic component of drugs (about 6%). There is evidence that the oxidation of irbesartan is mainly realized through the CYP2C9 enzyme of the hemoprotein P450; the isoenzyme CYRZA4 has a very insignificant effect on metabolic processes.

The pharmacokinetics of irbesartan is linear and depends on the size of the dosage (in the range of 0.01-0.6 g). There was a weaker dose-related increase in drug absorption when consumed orally in portions of more than 0.6 g (this is twice the maximum allowable dosage), but the mechanism of this reaction has not been determined. Indicators of plasma Cmax reaches after 1.5-2 hours from the moment of drug administration.

The level of renal and systemic clearance of the drug is 3-3.5, as well as 157-176 ml per minute.

The terminal half-life of irbesartan is 11-15 hours. An equilibrium intraplasmic indicator is noted after 3 days from the start of therapy (1 dose per day). Multiple administration of drugs once a day leads to limited accumulation of the drug inside the blood plasma (<20%).

The excretion of irbesartan with its metabolic elements is realized with bile and urine. After oral administration and administration of 14C-irbesartan, approximately 20% of the radioactive components were excreted in the urine, and the remainder was excreted in feces. Less than 2% of a portion is excreted in the form of an unchanged element in the urine.

Dosing and administration

You need to consume Irbetan 1 time per day, at the same time, regardless of food intake. The tablets are swallowed without chewing, washed down with plain water.

The size of the most commonly used initial and maintenance dose is 0.15 g of the drug. If required, after 3-4 weeks, it can be increased to 0.3 g. With a subsequent increase in dosage, the effectiveness of the drug does not increase.

• Application for children

Not prescribed in pediatrics (under the age of 18).

Use Irbetan during pregnancy

Irbetan is forbidden to use during pregnancy, since it has an effect on the activity of the RAAS, which can negatively affect the intrauterine development of the fetus, causing the development of oligohydraminoses, delayed cranial ossification and impairment of kidney function.

It is also possible that the child develops a neonatal toxic reaction - a decrease in blood pressure, hyperkalemia and failure of kidney function.

If you become pregnant while taking drugs, you need to immediately cancel the treatment. At the same time, it is necessary through echography to check the renal function and the state of the skull in the fetus - if the patient, inadvertently, continued to use the medication for a long time already during pregnancy.

When planning to conceive, it is necessary to choose an alternative method of treatment.

Contraindications

The main contraindications:

• severe intolerance to the elements of the drug;
• breastfeeding and gestation;
• lack of lactase, galactosemia and glucose-galactose malabsorption.

With extreme caution, the medication is used in such situations:

• stenosis affecting the arteries of both kidneys or the artery of the only working kidney;
• insufficiency of liver function or severe heart failure;
• dehydration;
• an excess of Na element inside the body;
• prolonged diarrhea or vomiting;
• salt-free dietary regimen;
• dialysis procedures;
• aldosteronism in its primary form;
• mitral or aortic stenosis;
• hypertrophic type of cardiomyopathy, which has an obstructive nature.

Side effects Irbetan

Adverse symptoms associated with drug administration are usually temporary and moderate. Among them:

• tachycardia, increased fatigue, orthostatic collapse, dizziness, tinnitus and headaches;
• vomiting, constipation, dyspepsia, nausea, heartburn, diarrhea and dysgeusia;
• hepatic dysfunction and hepatitis;
• renal dysfunction;
• cough;
• arthralgia or pain affecting the joints, sternum or muscles;
• epidermal hyperemia, Quincke's edema, vasculitis of the leukocytoclastic type, urticaria and rashes;
• impotence;
• hyperkalemia or decreased blood hemoglobin values;
• myalgia or cramps affecting the muscles.

Overdose

To date, no cases of Irbetan intoxication have been reported. In the case of taking extremely high dosages (more than 0.9 g per day), tachycardia or bradycardia may develop, and the blood pressure level may also drop dramatically.

With such violations, gastric lavage and the intake of activated charcoal are performed. In addition, it is necessary to establish medical monitoring of the patient and carry out symptomatic actions, if necessary.

Hemodialysis procedures for drug poisoning will be ineffective.

Interactions with other drugs

Irbetan is allowed to be combined with thiazide-type diuretics, substances that block the action of Ca channels, as well as with ACE inhibitors.

In cases where the patient was treated with large portions of diuretics for a long time before the administration of drugs, the risk of a decrease in blood pressure at the initial stage of therapy increases due to dehydration of the body.

Combination with potassium-sparing diuretics and potassium-containing dietary supplements may increase plasma potassium levels.

The drug should not be combined with amiodarone, fluconazole and rifamipicin, and in addition with cimetidine, lithium, sulfafenozole, omeprazole and ketoconazole.

The introduction of the drug together with NSAIDs can lead to a weakening of its therapeutic activity.

Storage conditions

Irbetan must be kept in a dark place, closed from the penetration of children. Temperature values are not higher than + 25oC.

Shelf life

Irbetane can be used for a 36-month term from the date of manufacture of the medicinal product.

Analogs

The analogs of the medicine are the substances Konverium, Votum and Irsar with Angizar, and besides this, Aprovel, Diosar and Ibertan with Valzar, as well as Coaprovel and Diostar.