Quinapril hydrochloride is used alone or in combination with other classes of antihypertensive agents (e.g., thiazide diuretics) in the management of hypertension. Quinapril also may be used in conjunction with agents such as cardiac glycosides, diuretics, and β-adrenergic blocking agents (β-blockers) in the management of heart failure.
Because captopril, another angiotensin-converting enzyme (ACE) inhibitor, may cause serious adverse effects (e.g., neutropenia, agranulocytosis), particularly in patients with renal impairment (especially those with collagen vascular disease) or in patients receiving immunosuppressive therapy, the possibility that similar adverse effects may occur with quinapril should be considered since current evidence is insufficient to rule out such risk.
Quinapril hydrochloride is used alone or in combination with other classes of antihypertensive agents in the management of hypertension. ACE inhibitors are considered one of several preferred antihypertensive drugs for the initial management of hypertension; other options include angiotensin II receptor antagonists, calcium-channel blockers, and thiazide diuretics. While there may be individual differences with respect to specific outcomes, these antihypertensive drug classes all produce comparable effects on overall mortality and cardiovascular, cerebrovascular, and renal outcomes. ACE inhibitors may be particularly useful in the management of hypertension in patients with certain coexisting conditions such as heart failure, ischemic heart disease, diabetes mellitus, chronic kidney disease, or cerebrovascular disease or following myocardial infarction. (See Uses: Hypertension in and in )
In general, black hypertensive patients tend to respond better to monotherapy with thiazide diuretics or calcium-channel blockers than to monotherapy with ACE inhibitors. Although ACE inhibitors have lowered blood pressure in all races studied, monotherapy with these agents has produced a smaller reduction in blood pressure in black hypertensive patients, a population associated with low-renin hypertension; however, this population difference in response does not appear to occur during combined therapy with an ACE inhibitor and a thiazide diuretic or calcium-channel blocker. In addition, ACE inhibitors appear to produce a higher incidence of angioedema in black patients than in other races studied. (See Race under Hypertension: Other Special Considerations for Antihypertensive Therapy, in Uses in and in )
For additional information on the role of ACE inhibitors in the management of hypertension, and in . For information on overall principles and expert recommendations for treatment of hypertension,
Quinapril is used in the management of symptomatic heart failure, usually in conjunction with other agents such as cardiac glycosides, diuretics, and β-blockers.
Current guidelines for the management of heart failure in adults generally recommend a combination of drug therapies to reduce morbidity and mortality, including neurohormonal antagonists (e.g., ACE inhibitors, angiotensin II receptor antagonists, angiotensin receptor-neprilysin inhibitors [ARNIs], β-blockers, aldosterone receptor antagonists) that inhibit the detrimental compensatory mechanisms in heart failure. Additional agents (e.g., cardiac glycosides, diuretics, sinoatrial modulators [i.e., ivabradine]) added to a heart failure treatment regimen in selected patients have been associated with symptomatic improvement and/or reduction in heart failure-related hospitalizations. Experts recommend that all asymptomatic patients with reduced left ventricular ejection fraction (LVEF) (American College of Cardiology Foundation [ACCF]/American Heart Association [AHA] stage B heart failure) receive therapy with an ACE inhibitor and β-blocker to prevent symptomatic heart failure and to reduce morbidity and mortality. In patients with prior or current symptoms of chronic heart failure and reduced LVEF (ACCF/AHA stage C heart failure), ACCF, AHA, and the Heart Failure Society of America (HFSA) recommend inhibition of the renin-angiotensin-aldosterone (RAA) system with an ACE inhibitor, angiotensin II receptor antagonist, or ARNI in conjunction with a β-blocker, and an aldosterone antagonist in selected patients, to reduce morbidity and mortality. While ACE inhibitors have been the preferred drugs for inhibition of the RAA system because of their established benefits in patients with heart failure and reduced ejection fraction, some evidence indicates that therapy with sacubitril/valsartan, an ARNI, may be more effective than ACE inhibitor therapy (enalapril) in reducing cardiovascular death and heart failure-related hospitalization. ACCF, AHA, and HFSA recommend that patients with chronic symptomatic heart failure and reduced LVEF (New York Heart Association [NYHA] class II or III) who are able to tolerate an ACE inhibitor or angiotensin II receptor antagonist be switched to therapy containing an ARNI to further reduce morbidity and mortality. However, in patients in whom an ARNI is not appropriate, continued use of an ACE inhibitor for all classes of heart failure with reduced ejection fraction remains strongly advised. In patients in whom an ARNI or ACE inhibitor is not appropriate, an angiotensin II receptor antagonist may be used. For additional information on the use of ACE inhibitors in the management of heart failure, see Uses: Heart Failure, and in .
Many patients with heart failure respond to quinapril with improvement in cardiac function indexes, symptomatic (e.g., dyspnea, fatigue) relief, improved functional capacity, and increased exercise tolerance. In some studies, improvement in cardiac function indexes and exercise tolerance were sustained for up to 6 months. In some patients, beneficial effects have been sustained for up to 12-24 months. Although additional studies are needed to determine the specific role of quinapril in the management of heart failure and its long-term efficacy, preliminary data indicate that the efficacy of the drug appears to be similar to that of enalapril and lisinopril. Because the renin-angiotensin system appears to substantially contribute to preservation of glomerular filtration in patients with heart failure in whom renal function is severely compromised, therapy with an ACE inhibitor may adversely affect renal function. However, at least one study appears to indicate that poor renal function may not increase the risk of renal deterioration in heart failure patients receiving quinapril. and
Both ACE inhibitors and angiotensin II receptor antagonists have been shown to slow the rate of progression of renal disease in patients with diabetes mellitus and persistent albuminuria, and use of a drug from either class is recommended in such patients with modestly elevated (30-300 mg/24 hours) or higher (exceeding 300 mg/24 hours) levels of urinary albumin excretion. The usual precautions of ACE inhibitor or angiotensin II receptor antagonist therapy in patients with substantial renal impairment should be observed. For additional information on the use of ACE inhibitors in the treatment of diabetic nephropathy, see