Quinapril

Hypertension Quinapril tablets, USP are indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including the class to which this drug principally belongs. There are no controlled trials demonstrating risk reduction with quinapril tablets, USP. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals.

Quinapril is deesterified to the principal metabolite, quinaprilat, which is an inhibitor of ACE activity in human subjects and animals. ACE is a peptidyl dipeptidase that catalyzes the conversion of angiotensin I to the vasoconstrictor, angiotensin II. The effect of quinapril in hypertension and in congestive heart failure (CHF) appears to result primarily from the inhibition of circulating and tissue ACE activity, thereby reducing angiotensin II formation. Quinapril inhibits the elevation in blood pressure caused by intravenously administered angiotensin I, but has no effect on the pressor response to angiotensin II, norepinephrine or epinephrine. Angiotensin II also stimulates the secretion of aldosterone from the adrenal cortex, thereby facilitating renal sodium and fluid reabsorption. Reduced aldosterone secretion by quinapril may result in a small increase in serum potassium.

Hypertension Monotherapy The recommended initial dosage of quinapril tablets in patients not on diuretics is 10 or 20 mg once daily. Dosage should be adjusted according to blood pressure response measured at peak (2 to 6 hours after dosing) and trough (predosing). Generally, dosage adjustments should be made at intervals of at least 2 weeks. Most patients have required dosages of 20, 40, or 80 mg/day, given as a single dose or in two equally divided doses. In some patients treated once daily, the antihypertensive effect may diminish toward the end of the dosing interval. In such patients an increase in dosage or twice daily administration may be warranted. In general, doses of 40 to 80 mg and divided doses give a somewhat greater effect at the end of the dosing interval.

Quinapril tablets are contraindicated in patients who are hypersensitive to this product and in patients with a history of angioedema related to previous treatment with an ACE inhibitor. Quinapril tablets are contraindicated in combination with a neprilysin inhibitor (e.g., sacubitril). Do not administer quinapril tablets are within 36 hours of switching to or from sacubitril/valsartan, a neprilysin inhibitor. Do not co-administer quinapril tablets with aliskiren in patients with diabetes.

Boxed warning (fetal toxicity): When pregnancy is detected, discontinue quinapril hydrochloride as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus. See WARNINGS: Fetal Toxicity Anaphylactoid and Possibly Related Reactions Presumably because ACE inhibitors affect the metabolism of eicosanoids and polypeptides, including endogenous bradykinin, patients receiving ACE inhibitors (including quinapril hydrochloride ) may be subject to a variety of adverse reactions, some of them serious. Head and Neck Angioedema Angioedema of the face, extremities, lips, tongue, glottis, and larynx has been reported in patients treated with ACE inhibitors and has been seen in 0.1% of patients receiving quinapril hydrochloride.

Hypertension Quinapril hydrochloride has been evaluated for safety in 4960 subjects and patients. Of these, 3203 patients, including 655 elderly patients, participated in controlled clinical trials. Quinapril hydrochloride has been evaluated for long-term safety in over 1400 patients treated for 1 year or more. Adverse experiences were usually mild and transient. In placebo-controlled trials, discontinuation of therapy because of adverse events was required in 4.7% of patients with hypertension. Adverse experiences probably or possibly related to therapy or of unknown relationship to therapy occurring in 1% or more of the 1563 patients in placebo-controlled hypertension trials who were treated with quinapril hydrochloride are shown below.

Concomitant diuretic therapy As with other ACE inhibitors, patients on diuretics, especially those on recently instituted diuretic therapy, may occasionally experience an excessive reduction of blood pressure after initiation of therapy with quinapril hydrochloride. The possibility of hypotensive effects with quinapril hydrochloride may be minimized by either discontinuing the diuretic or cautiously increasing salt intake prior to initiation of treatment with quinapril hydrochloride. If it is not possible to discontinue the diuretic, the starting dose of quinapril should be reduced. Agents increasing serum potassium Coadministration of quinapril hydrochloride with other drugs that raise serum potassium levels may result in hyperkalemia. Monitor serum potassium in such patients.

Store at 20° to 25°C (68° to 77°F). Protect from light.