accupril clinical data

Quinapril hydrochloride is chemically described as [3S-[2[R*(R*)], 3R*]]-2-[2-[[1-(ethoxycarbonyl)-3-phenylpropyl]amino]-1-oxopropyl]-1,2,3,4-tetrahydro-3-isoquinolinecarboxylicacid, monohydrochloride accupril clinical data. Its empirical formula is C 25 H 30 N 2 O 5 ·HCland its structural formula is:

Quinapril hydrochloride is a white to off-white amorphous powder that is freelysoluble in aqueous solvents accupril clinical data.

ACCUPRIL tablets contain 5 mg, 10 mg, 20 mg, or 40 mg of quinapril for oraladministration accupril clinical data. Each tablet also contains candelilla wax, crospovidone, gelatin,lactose, magnesium carbonate, magnesium stearate, synthetic red iron oxide,and titanium dioxide accupril clinical data.

CLINICAL PHARMACOLOGY
Mechanism of Action: Quinapril is deesterified to the principal metabolite,quinaprilat, which is an inhibitor of ACE activity in human subjects and animals accupril clinical data. ACE is a peptidyl dipeptidase that catalyzes the conversion of angiotensin Ito the vasoconstrictor, angiotensin II accupril clinical data. The effect of quinapril in hypertensionand in congestive heart failure (CHF) appears to result primarily from the inhibitionof circulating and tissue ACE activity, thereby reducing angiotensin II formation accupril clinical data. Quinapril inhibits the elevation in blood pressure caused by intravenously administeredangiotensin I, but has no effect on the pressor response to angiotensin II,norepinephrine or epinephrine accupril clinical data. Angiotensin II also stimulates the secretionof aldosterone from the adrenal cortex, thereby facilitating renal sodium andfluid reabsorption accupril clinical data. Reduced aldosterone secretion by quinapril may result ina small increase in serum potassium accupril clinical data. In controlled hypertension trials, treatmentwith ACCUPRIL alone resulted in mean increases in potassium of 0.07 mmol/L (seePRECAUTIONS ) accupril clinical data. Removal of angiotensin II negative feedback on renin secretionleads to increased plasma renin activity (PRA) accupril clinical data.

While the principal mechanism of antihypertensive effect is thought to be throughthe renin-angiotensin-aldosterone system, quinapril exerts antihypertensiveactions even in patients with low renin hypertension accupril clinical data. ACCUPRIL was an effectiveantihypertensive in all races studied, although it was somewhat less effectivein blacks (usually a predominantly low renin group) than in nonblacks accupril clinical data. ACE isidentical to kininase II, an enzyme that degrades bradykinin, a potent peptidevasodilator; whether increased levels of bradykinin play a role in the therapeuticeffect of quinapril remains to be elucidated accupril clinical data.

Pharmacokinetics and Metabolism: Following oral administration, peak plasmaquinapril concentrations are observed within one hour accupril clinical data. Based on recovery ofquinapril and its metabolites in urine, the extent of absorption is at least60% accupril clinical data. The rate and extent of quinapril absorption are diminished moderately (approximately25-30%) when ACCUPRIL tablets are administered during a high-fat meal accupril clinical data. Followingabsorption, quinapril is deesterified to its major active metabolite, quinaprilat(about 38% of oral dose), and to other minor inactive metabolites accupril clinical data. Followingmultiple oral dosing of ACCUPRIL, there is an effective accumulation half-lifeof quinaprilat of approximately 3 hours, and peak plasma quinaprilat concentrationsare observed approximately 2 hours post-dose accupril clinical data. Quinaprilat is eliminated primarilyby renal excretion, up to 96% of an IV dose, and has an elimination half-lifein plasma of approximately 2 hours and a prolonged terminal phase with a half-lifeof 25 hours accupril clinical data. The pharmacokinetics of quinapril and quinaprilat are linear overa single-dose range of 5-80 mg doses and 40-160 mg in multiple daily doses accupril clinical data. Approximately 97% of either quinapril or quinaprilat circulating in plasma isbound to proteins accupril clinical data.

In patients with renal insufficiency, the elimination half-life of quinaprilatincreases as creatinine clearance decreases accupril clinical data. There is a linear correlation betweenplasma quinaprilat clearance and creatinine clearance accupril clinical data. In patients with end-stagerenal disease, chronic hemodialysis or continuous ambulatory peritoneal dialysishas little effect on the elimination of quinapril and quinaprilat accupril clinical data. Eliminationof quinaprilat may be reduced in elderly patients (>/=65 years) and in thosewith heart failure; this reduction is attributable to decrease in renal function(see DOSAGE AND ADMINISTRATION ) accupril clinical data. Quinaprilat concentrations are reduced inpatients with alcoholic cirrhosis due to impaired deesterification of quinapril accupril clinical data. Studies in rats indicate that quinapril and its metabolites do not cross theblood-brain barrier accupril clinical data.

Pharmacodynamics and Clinical Effects
Hypertension: Single doses of 20 mg of ACCUPRIL provide over 80% inhibitionof plasma ACE for 24 hours accupril clinical data. Inhibition of the pressor response to angiotensinI is shorter-lived, with a 20 mg dose giving 75% inhibition for about 4 hours,50% inhibition for about 8 hours, and 20% inhibition at 24 hours accupril clinical data. With chronicdosing, however, there is substantial inhibition of angiotensin II levels at24 hours by doses of 20-80 mg accupril clinical data.

Administration of 10 to 80 mg of ACCUPRIL to patients with mild to severe hypertensionresults in a reduction of sitting and standing blood pressure to about the sameextent with minimal effect on heart rate accupril clinical data. Symptomatic postural hypotension isinfrequent although it can occur in patients who are salt- and/or volume-depleted(see WARNINGS ) accupril clinical data. Antihypertensive activity commences within 1 hour with peakeffects usually achieved by 2 to 4 hours after dosing accupril clinical data. During chronic therapy,most of the blood pressure lowering effect of a given dose is obtained in 1-2weeks accupril clinical data. In multiple-dose studies, 10-80 mg per day in single or divided doseslowered systolic and diastolic blood pressure throughout the dosing interval,with a trough effect of about 5-11/3-7 mm Hg accupril clinical data. The trough effect represents about50% of the peak effect accupril clinical data. While the dose-response relationship is relatively flat,doses of 40-80 mg were somewhat more effective at trough than 10-20 mg, andtwice daily dosing tended to give a somewhat lower trough blood pressure thanonce daily dosing with the same total dose accupril clinical data. The antihypertensive effect of ACCUPRILcontinues during long-term therapy, with no evidence of loss of effectiveness accupril clinical data.

Hemodynamic assessments in patients with hypertension indicate that blood pressurereduction produced by quinapril is accompanied by a reduction in total peripheralresistance and renal vascular resistance with little or no change in heart rate,cardiac index, renal blood flow, glomerular filtration rate, or filtration fraction accupril clinical data.

Use of ACCUPRIL with a thiazide diuretic gives a blood-pressure lowering effectgreater than that seen with either agent alone accupril clinical data.

In patients with hypertension, ACCUPRIL 10-40 mg was similar in effectivenessto captopril, enalapril, propranolol, and thiazide diuretics accupril clinical data.

Therapeutic effects appear to be the same for elderly (>/=65 years of age)and younger adult patients given the same daily dosages, with no increase inadverse events in elderly patients accupril clinical data.

Heart Failure: In a placebo-controlled trial involving patients with congestiveheart failure treated with digitalis and diuretics, parenteral quinaprilat,the active metabolite of quinapril, reduced pulmonary capillary wedge pressureand systemic vascular resistance and increased cardiac output/index accupril clinical data. Similarfavorable hemodynamic effects were seen with oral quinapril in baseline-controlledtrials, and such effects appeared to be maintained during chronic oral quinapriltherapy accupril clinical data. Quinapril reduced renal hepatic vascular resistance and increased renaland hepatic blood flow with glomerular filtration rate remaining unchanged accupril clinical data.

A significant dose response relationship for improvement in maximal exercisetolerance has been observed with ACCUPRIL therapy accupril clinical data. Beneficial effects on theseverity of heart failure as measured by New York Heart Association (NYHA) classificationand Quality of Life and on symptoms of dyspnea, fatigue, and edema were evidentafter 6 months in a double-blind, placebo-controlled study accupril clinical data. Favorable effectswere maintained for up to two years of open label therapy accupril clinical data. The effects of quinaprilon long-term mortality in heart failure have not been evaluated accupril clinical data.

INDICATIONS AND USAGE
Hypertension
ACCUPRIL is indicated for the treatment of hypertension accupril clinical data. It may be used aloneor in combination with thiazide diuretics accupril clinical data.

Heart Failure
ACCUPRIL is indicated in the management of heart failure as adjunctive therapywhen added to conventional therapy including diuretics and/or digitalis accupril clinical data.

In using ACCUPRIL, consideration should be given to the fact that another angiotensin-convertingenzyme inhibitor, captopril, has caused agranulocytosis, particularly in patientswith renal impairment or collagen vascular disease accupril clinical data. Available data are insufficientto show that ACCUPRIL does not have a similar risk (see WARNINGS ) accupril clinical data.

Angioedema in black patients: Black patients receiving ACE inhibitor monotherapyhave been reported to have a higher incidence of angioedema compared to non-blacks accupril clinical data. It should also be noted that in controlled clinical trials ACE inhibitors havean effect on blood pressure that is less in black patients than in non-blacks accupril clinical data.

CONTRAINDICATIONS
ACCUPRIL is contraindicated in patients who are hypersensitive to this productand in patients with a history of angioedema related to previous treatment withan ACE inhibitor accupril clinical data.

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