Comparison of Enalapril 40mg and Lisinopril 40mg Potency
Lisinopril 40mg is more potent than enalapril 40mg due to its longer duration of action and greater blood pressure lowering effect in the latter half of the dosing interval. 1, 2
Comparative Efficacy of ACE Inhibitors
- Both enalapril and lisinopril are angiotensin-converting enzyme (ACE) inhibitors that effectively lower blood pressure and reduce cardiovascular morbidity and mortality 3
- While both medications belong to the same class and have similar mechanisms of action, they differ in their pharmacokinetic properties 4
- Studies directly comparing lisinopril and enalapril have shown that lisinopril has a longer duration of action and maintains better blood pressure control throughout the 24-hour dosing period 1, 2
Specific Differences in Potency
- Lisinopril produces greater inhibition of plasma ACE 24 hours after dosing compared to enalapril 2
- In comparative studies, lisinopril lowered mean 24-hour systolic blood pressure significantly more than enalapril after 4 weeks of treatment (14/7 ± 2/1 mmHg vs 9/6 ± 2/1 mmHg) 2
- The superior blood pressure lowering effect of lisinopril is particularly evident in the second 12 hours of the daily dosage interval 2
- Lisinopril has a higher trough:peak ratio (0.65) compared to enalapril (0.48), indicating more consistent blood pressure control throughout the dosing period 1
Clinical Implications
- When prescribing equivalent doses (40mg of each), lisinopril would be expected to provide more sustained blood pressure control throughout the 24-hour period 1, 2
- The European Society of Cardiology guidelines note that both medications are effective in regressing left ventricular hypertrophy and reducing cardiovascular events 3
- For patients with diabetes and kidney disease, both medications are recommended as first-line agents, though the longer duration of action of lisinopril may provide more consistent protection 3
Dosing Considerations
- Maximum recommended doses for both medications in hypertension and heart failure are similar (enalapril: 40mg daily; lisinopril: 40mg daily) 3
- For heart failure, the mean doses achieved in clinical trials were 16.6mg/day for enalapril and 32.5-35.0mg/day for lisinopril 3
- Both medications can be administered once daily, though enalapril is sometimes given in divided doses at higher doses 3
Important Clinical Caveats
- The clinical significance of the potency difference may be minimal in many patients, as both medications effectively lower blood pressure when dosed appropriately 3
- Individual patient response can vary, and some patients may respond better to one ACE inhibitor than another 3
- Both medications have similar side effect profiles including cough, angioedema, hyperkalemia, and potential for acute kidney injury 3
- Contraindications are identical for both medications: pregnancy, history of angioedema with ACE inhibitors, and bilateral renal artery stenosis 3
Conclusion
When comparing equivalent doses, lisinopril 40mg provides more sustained blood pressure control than enalapril 40mg due to its longer duration of action and greater ACE inhibition at 24 hours post-dose. This translates to better blood pressure control, particularly in the latter half of the dosing interval.