Comparative Effectiveness of Captopril vs Amlodipine in Managing Hypertension
Both captopril and amlodipine effectively reduce blood pressure, but amlodipine provides more sustained 24-hour blood pressure control with once-daily dosing compared to captopril's twice-daily requirement. 1, 2
Efficacy in Blood Pressure Reduction
Both medications significantly reduce blood pressure compared to baseline, with amlodipine achieving "normalized" diastolic blood pressure (<90 mmHg) in 90.5% of patients compared to 78.9% with captopril in direct comparison studies 3
Amlodipine demonstrates a more sustained 24-hour antihypertensive effect with once-daily dosing, while captopril's effect diminishes during the final 3 hours of each dosing interval, requiring twice-daily administration 1, 2
The ALLHAT trial showed that amlodipine was as effective as chlorthalidone in preventing coronary heart disease mortality and morbidity, establishing it as a first-line agent for hypertension 4, 5
The Captopril Prevention Project (CAPPP) trial showed that captopril-treated patients had significantly lower relative risks for all-cause mortality (RR, 0.54), cardiovascular events (RR, 0.59), and myocardial infarction (RR, 0.34) compared to beta-blockers with or without diuretics, though this study had methodological limitations 6
Special Population Considerations
For patients with diabetes, the UKPDS found no significant differences in macrovascular events between captopril and beta-blockers, suggesting that blood pressure reduction itself may be more important than the specific agent used 6
In black patients, ACE inhibitors like captopril are less effective than calcium channel blockers like amlodipine in reducing cardiovascular endpoints and stroke 6
For patients with heart failure, captopril is indicated for treatment of congestive heart failure, usually in combination with diuretics and digitalis 7
Amlodipine can be used as a step 3 agent in heart failure patients with persistent hypertension despite treatment with ACE inhibitors, beta-blockers, and mineralocorticoid receptor antagonists 4
Dosing and Administration
Amlodipine is administered once daily at doses of 5-10 mg, providing 24-hour blood pressure control 5, 1
Captopril requires twice-daily dosing (typically 25-50 mg twice daily) for optimal blood pressure control 7, 2
The combination of amlodipine and captopril has been shown to be effective and well-tolerated in patients with resistant hypertension 8, 9
Side Effect Profiles
Amlodipine's common side effects include peripheral edema and flushing 8, 9
Captopril's side effects include cough, taste disturbances, and rarely, neutropenia/agranulocytosis, particularly in patients with impaired renal function or collagen vascular disease 7
Clinical Decision-Making Algorithm
For most patients with uncomplicated hypertension:
For patients with heart failure:
- Captopril is preferred as it is specifically indicated for heart failure treatment 7
For black patients:
- Amlodipine is preferred as ACE inhibitors like captopril are less effective in this population 6
For patients with diabetic nephropathy:
- Captopril is preferred as it is specifically indicated for treatment of diabetic nephropathy 7
For patients with left ventricular dysfunction after myocardial infarction:
- Captopril is preferred as it is indicated to improve survival in these patients 7
Common Pitfalls and Caveats
Do not use captopril in pregnant women as ACE inhibitors can cause fetal harm when administered during pregnancy 7
Monitor for angioedema with captopril, which occurs at a higher rate in black patients 7
Be aware that many patients may require combination therapy to achieve optimal blood pressure control, as demonstrated in the ALLHAT study 4
Consider that the blood pressure reduction itself may be more important than the specific agent used, particularly in diabetic patients 6