Neosartan Plus Mechanism of Action

Pharmacology: Pharmacodynamics: Losartan Potassium: It is an angiotensin II receptor blocker with antihypertensive activity due mainly to selective blockage of AT₁ receptors and the consequent reduced pressure effect of angiotensin II.
Hydrochlorothiazide: It is a diuretic antihypertensive.
Pharmacokinetics: Losartan Potassium: It is readily absorbed from the gastrointestinal tract (GIT) following oral administration, with an oral bioavailability of about 33%. It undergoes first-pass metabolism to form an active carboxylic acid metabolite E-3174 (EXP-3174), which has greater pharmacological activity than losartan and some inactive metabolites. Metabolism is primarily by cytochrome P450 isoenzyme CYP2C9 and CYP3A4. Peak plasma concentrations of losartan and E-3174 occur about 1 hr and 3-4 hrs, respectively, after an oral dose. Both losartan and E-3174 are more than 98% bound to plasma proteins. Losartan is excreted in the urine and in the feces via bile, as unchanged drug and metabolites. Following oral dosing, about 35% of the dose is excreted in the urine and about 60% in the feces. The terminal elimination t_½ of losartan and E-3174 are about 1.5-2.5 hrs and 3-9 hrs, respectively.
Hydrochlorothiazide: It is fairly rapidly absorbed from the GIT. It is reported to have a bioavailability of about 65-70%. It has been estimated to have a plasma t_½ of between about 5-15 hrs and appears to be preferentially bound to red blood cells. It is excreted mainly unchanged in the urine. Hydrochlorothiazide crosses the placental barrier and is distributed into breast milk.