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DIOVAN HCT(valsartan and hydrochlorothiazide) tablet, film c(十一)
alysis has not been established. The most common signs and symptoms observed in patients are those caused by electrolyte depletion (hypokalemia, hypochloremia, hyponatremia) and dehydration resulting from excessive diuresis. If digitalis has also been administered, hypokalemia may accentuate cardiac arrhythmias.
In rats and marmosets, single oral doses of valsartan up to 1524 and 762mg/kg in combination with hydrochlorothiazide at doses up to 476 and 238mg/kg, respectively, were very well tolerated without any treatment-related effects. These no adverse effect doses in rats and marmosets, respectively, represent 46.5 and 23 times the maximum recommended human dose (MRHD) of valsartan and 188 and 113 times the MRHD of hydrochlorothiazide on amg/m2 basis. (Calculations assume an oral dose of 320mg/day valsartan in combination with 25mg/day hydrochlorothiazide and a 60-kg patient.)
Valsartan: Valsartan was without grossly observable adverse effects at single oral doses up to 2000mg/kg in rats and up to 1000mg/kg in marmosets, except for salivation and diarrhea in the rat and vomiting in the marmoset at the highest dose (60 and 31 times, respectively, the maximum recommended human dose on a mg/m2 basis). (Calculations assume an oral dose of 320mg/day and a 60-kg patient.)
Hydrochlorothiazide: The oral LD50 of hydrochlorothiazide is greater than 10g/kg in both mice and rats, which represents 2027 and 4054 times, respectively, the maximum recommended human dose on amg/m2 basis. (Calculations assume an oral dose of 25mg/day and a 60-kg patient.)
11 DESCRIPTION
DiovanHCT (valsartan and hydrochlorothiazide, USP) is a combination of valsartan, an orally active, specific angiotensin II receptor blocker (ARB) acting on the AT1 receptor subtype, and hydrochlorothiazide, a diuretic.
Valsartan, a nonpeptide molecule, is chemically described as N-(1-oxopentyl)-N-[[2′-(1H-tetrazol-5-yl)[1,1′-biphenyl]-4-yl]methyl]-L-Valine. Its empirical formula is C24H29N5O3, its molecular weight is 435.5, and its structural formula is
Valsartan is a white to practically white fine powder. It is soluble in ethanol and methanol and slightly soluble in water.
Hydrochlorothiazide USP is a white, or practically white, practically odorless, crystalline powder. It is slightly soluble in water; freely soluble in sodium hydroxide solution, in n-butylamine, and in dimethylformamide; sparingly soluble in methanol; and insoluble in ether, in chloroform, and in dilute mineral acids. Hydrochlorothiazide is chemically described as 6-chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide.
Hydrochlorothiazide is a thiazide diuretic. Its empirical formula is C7H8ClN3O4S2, its molecular weight is 297.73, and its structural formula is
DiovanHCT tablets are formulated for oral administration to contain valsartan and hydrochlorothiazide, USP 80/12.5mg, 160/12.5mg, 160/25mg, 320/12.5mg and 320/25mg. The inactive ingredients of the tablets are colloidal silicon dioxide, crospovidone, hydroxypropyl methylcellulose, iron oxides, magnesium stearate, microcrystalline cellulose, polyethylene glycol, talc, and titanium dioxide.
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
Angiotensin II is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE, kininase II). Angiotensin II is the principal pressor agent of the renin-angiotensin system |
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