Quinapril

Quinapril is an ACE inhibitor previously used for hypertension and heart failure.

It has largely been discontinued in the United States due to nitrosamine impurity concerns (2022 recall), but remains pharmacologically representative of the ACE inhibitor class.

Class: → ACE Inhibitors


Mechanism of Action

• Inhibits Angiotensin-Converting Enzyme (ACE) • ↓ Angiotensin II • ↓ Aldosterone • ↑ Bradykinin

Net Effects: • ↓ Systemic vascular resistance • ↓ Blood pressure • ↓ Ventricular remodeling (in HF)

Mechanistically identical to other ACE inhibitors.


Unique Features

• Prodrug (converted to quinaprilat) • Historically used in hypertension and heart failure • Withdrawn in the U.S. market (2022) due to nitrosamine contamination risk

Clinical relevance now primarily academic/reference.


Indications (Historical)

Hypertension

• Effective blood pressure reduction

Hypertension Module


Heart Failure (HFrEF)

• Used similarly to other ACE inhibitors • Not commonly used in modern GDMT

Heart Failure Module


Dosing (Historical)

Hypertension: • Start: 10–20 mg once daily • Typical range: 20–80 mg daily (once or divided)

Heart Failure: • Often started at lower doses (5–10 mg daily) • Titrated as tolerated


Pharmacokinetics

• Prodrug → activated in liver • Renally cleared • Half-life of active metabolite ~2 hours • Duration supports once- or twice-daily dosing

Dose adjustment required in renal impairment.


Adverse Effects

Class Effects: • Dry cough • Hyperkalemia • Hypotension • Angioedema (rare) • Mild creatinine elevation

No significant pharmacologic differences from other ACE inhibitors.


Contraindications

• Pregnancy • History of ACE inhibitor–induced angioedema • Bilateral renal artery stenosis


Clinical Pearls

✔ Pharmacologically similar to other ACE inhibitors ✔ Prodrug ✔ Withdrawn from U.S. market (2022 recall) ✔ Primarily of historical/reference value


Related:

ACE InhibitorsLisinoprilReturn to CV Modules