Captopril is the first ACE inhibitor developed and is a short-acting agent used in hypertension, heart failure, and post–myocardial infarction care.
Class: → ACE Inhibitors
• Inhibits Angiotensin-Converting Enzyme (ACE) • ↓ Angiotensin II • ↓ Aldosterone • ↑ Bradykinin
Net Effects: • ↓ Systemic vascular resistance (afterload) • Mild ↓ preload • ↓ Ventricular remodeling • ↓ Blood pressure
Mechanism identical to other ACE inhibitors.
• Short half-life (requires multiple daily dosing) • Active drug (not a prodrug) • Contains sulfhydryl group (↑ certain side effects) • Rapid onset — sometimes used in hypertensive urgency
Because of short duration, less commonly used for chronic outpatient therapy compared to lisinopril or enalapril.
• Mortality benefit demonstrated in early ACE trials • Less convenient than longer-acting ACE inhibitors
• Reduces ventricular remodeling • Improves survival (SAVE trial era ACE data)
Hypertension: • Start: 12.5–25 mg 2–3 times daily • Usual range: 25–50 mg 2–3 times daily
Heart Failure: • Start: 6.25–12.5 mg three times daily • Target: 50 mg three times daily (if tolerated)
Short duration → typically dosed three times daily.
• Active drug (no hepatic activation required) • Renally cleared • Half-life ~2 hours • Rapid onset of action
Dose adjustment required in renal impairment.
Class Effects: • Dry cough • Hyperkalemia • Hypotension • Angioedema (rare)
Unique/More Common with Captopril: • Rash • Dysgeusia (altered taste) • Rare neutropenia (historical high-dose issue)
Monitor: • Serum creatinine • Potassium
Recheck labs 1–2 weeks after initiation or dose adjustment.
Mild creatinine increase is expected.
• Pregnancy • History of ACE inhibitor–induced angioedema • Bilateral renal artery stenosis
✔ First ACE inhibitor developed ✔ Short-acting (TID dosing) ✔ Useful when rapid titration needed ✔ More taste disturbance than other ACE inhibitors ✔ Less commonly used long-term due to dosing frequency
Related:
→ ACE Inhibitors → Lisinopril → Enalapril → Return to CV Modules