Description of the medicine: Losartan (Losartan)
2-Butyl-4-chloro-1- [2- (1H-tetrazol-5-ylphenyl) benzyl] imidazol-5-methanol.
Available in the form of potassium salt.
Synonym: Cozaar, Cozaar.
White or off-white crystalline powder. It is soluble in water and poorly in organic solvents.
The first non-peptide angiotensin II receptor blocker exhibiting high affinity and selectivity for AT 1 subtype receptors.
By blocking AT 1 angiotensin receptors, losartan reduces arterial vasoconstriction caused by angiotensin II, secretion of aldosterone, arginine-vasopressin, norepinephrine and endothelin-I, and with prolonged use, the proliferative effects of angiotensin II in relation to vascular fibroids and cardiomyocytes.
Reduces total peripheral resistance (afterload), systemic blood pressure and pressure in the pulmonary circulation.
It is rapidly absorbed in the digestive tract, bioavailability is about 20-30%, C max - 1 hour, T Ѕ - 1.5-2 hours (metabolite - 6-9 hours); undergoes biotransformation in the liver with the formation of an active metabolite, excreted mainly with feces.
The antihypertensive effect persists for more than 24 hours, due to the action of the metabolite of losartan, which is 10-40 times more active than he is.
Applied with arterial hypertension and more recently with congestive heart failure.
In case of arterial hypertension, usually 0.05 g (50 mg) is used once a day, if necessary, the daily dose can be increased after a few weeks to 0.1 g (for elderly patients with impaired liver and kidney function, the dose is reduced).
In congestive heart failure, the initial dose is 0.0125 g (12.5 mg) once a day.
The effect of losartan develops slowly and reaches a maximum after 3-6 weeks.
Possible side effects: diarrhea, dizziness, headache, cough, taste disturbance, peripheral neuropathies, arrhythmias, exacerbation of angina pectoris, allergic reactions, etc.
Losartan is contraindicated in hyperkalemia, pregnancy and breastfeeding, in childhood.
Compatible with other antihypertensive drugs.
Release form: tablets of 0.0125 and 0.05 g (12.5 and 50 mg) (N. 7, 10, 14).
Gizaar - tablets containing losartan potassium 0.05 g (50 mg) and hydrochlorothiazide 0.0125 g (12.5 mg).
There is evidence that gizaar is superior to losartan in antihypertensive efficacy and ability to improve quality of life.