Hyzaar

[Losartan/HCTZ]

Drug Description
DESCRIPTION

HYZAAR * 50-12.5 (losartan potassium-hydrochlorothiazide) and HYZAAR * 100-25 (losartan potassium-hydrochlorothiazide), combine an angiotensin II receptor (type AT1 ) antagonist and a diuretic, hydrochlorothiazide. Losartan potassium, a non-peptide molecule, is chemically described as 2-butyl-4-chloro-1-[ p-( o-1H-tetrazol-5-ylphenyl) benzyl] imidazole-5-methanol monopotassium salt. Its empirical formula is C22 H22 ClKN6 O.

Losartan potassium is a white to off-white free-flowing crystalline powder with a molecular weight of 461.01. It is freely soluble in water, soluble in alcohols, and slightly soluble in common organic solvents, such as acetonitrile and methyl ethyl ketone. Oxidation of the 5-hydroxymethyl group on the imidazole ring results in the active metabolite of losartan. Hydrochlorothiazide is 6-chloro-3, 4-dihydro-2H-1, 2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide. Its empirical formula is C7 H8 ClN3 O4 S2.

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* Registered trademark of E. I. du Pont de Nemours and Company, Wilmington, Delaware, USA
COPYRIGHT © MERCK & CO., Inc., 1995
Whitehouse Station, NJ, USA
All rights reserved

Hydrochlorothiazide is a white, or practically white, crystalline powder with a molecular weight of 297.74, which is slightly soluble in water, but freely soluble in sodium hydroxide solution. HYZAAR is available for oral administration in two tablet combinations of losartan and hydrochlorothiazide.

HYZAAR 50-12.5 contains 50 mg of losartan potassium and 12.5 mg of hydrochlorothiazide.

HYZAAR 100-25 contains 100 mg of losartan potassium and 25 mg of hydrochlorothiazide. Inactive ingredients are microcrystalline cellulose, lactose hydrous, pregelatinized starch, magnesium stearate, hydroxypropyl cellulose, hypromellose, titanium dioxide and D& C yellow No. 10 aluminum lake.

HYZAAR 50-12.5 contains 4.24 mg (0. 108 mEq) of potassium and HYZAAR 100-25 contains 8.48 mg (0. 216 mEq) of potassium.