Equivalent Dosing When Converting from Lisinopril 10mg to Amlodipine
When converting from lisinopril 10mg to amlodipine, the appropriate equivalent starting dose is 5mg of amlodipine once daily. 1
Rationale for Dose Equivalence
The conversion between different antihypertensive drug classes requires understanding their relative potency and efficacy profiles:
- Lisinopril 10mg is considered a standard starting dose for an ACE inhibitor 1
- Amlodipine 5mg is the standard initial dose for calcium channel blockers in adults 1
Mechanism Differences
- Lisinopril works by inhibiting the angiotensin-converting enzyme, reducing angiotensin II production
- Amlodipine works by blocking calcium channels in vascular smooth muscle, causing vasodilation
Dosing Considerations
Initial Dosing
- Start with amlodipine 5mg once daily when converting from lisinopril 10mg 1
- For elderly patients or those with hepatic impairment, consider starting with 2.5mg of amlodipine
Titration Protocol
- Monitor blood pressure after 1-2 weeks of therapy 1
- If target blood pressure is not achieved, titrate to amlodipine 10mg daily (maximum recommended dose) 1
- Dose titration should be based on blood pressure response and tolerability
Evidence Supporting This Conversion
Research studies support this conversion approach:
- In comparative studies, amlodipine 5mg has shown similar antihypertensive efficacy to standard doses of ACE inhibitors 2
- A study evaluating amlodipine dosing found that 5mg once daily achieved target blood pressure in 56% of patients, while 10mg achieved it in 73% 3
Clinical Pearls and Caveats
Important Considerations
- Unlike ACE inhibitors, calcium channel blockers do not affect the renin-angiotensin-aldosterone system
- Amlodipine has a longer half-life than lisinopril, allowing for true once-daily dosing
- Monitor for different side effect profiles:
- Amlodipine: peripheral edema, headache, flushing
- Lisinopril: cough, hyperkalemia, angioedema
Common Pitfalls to Avoid
- Abrupt discontinuation of lisinopril - consider overlapping therapy for 1-2 days when switching
- Failure to monitor for edema with amlodipine therapy
- Not accounting for comorbidities that might influence drug selection (e.g., heart failure, diabetes)
Special Populations
- In patients with heart failure: ACE inhibitors are preferred over calcium channel blockers 1
- In patients with peripheral edema: amlodipine may exacerbate this condition
- In patients with chronic cough from lisinopril: switching to amlodipine may resolve this side effect
Remember that while these medications belong to different classes with different mechanisms of action, the goal is to maintain adequate blood pressure control while minimizing side effects.