What is an equivalent dose of felodipine (calcium channel blocker) for a patient taking indapamide (thiazide-like diuretic) 2.5mg daily?

There Is No Equivalent Dose: These Are Different Drug Classes

You cannot directly swap indapamide 2.5mg to an "equivalent dose" of felodipine because they work through completely different mechanisms—indapamide is a thiazide-like diuretic and felodipine is a calcium channel blocker. This is not a dose conversion; this is switching antihypertensive drug classes entirely.

Why This Question Has No Direct Answer

• Different mechanisms of action: Indapamide reduces blood pressure through diuresis and direct vasodilation, while felodipine works purely through calcium channel blockade and peripheral vasodilation 1, 2
• No dose equivalency exists: There are no studies or guidelines establishing equivalent antihypertensive potency between these two drug classes
• Individual response varies: Blood pressure response to different drug classes is highly patient-specific and cannot be predicted by dose conversion

The Correct Approach to This Switch

Step 1: Start Felodipine at Standard Initial Dosing

• Begin felodipine at 5mg once daily (standard starting dose for most calcium channel blockers in hypertension)
• Do not attempt to calculate an "equivalent" from the indapamide dose

Step 2: Decide Whether to Stop or Continue Indapamide

• If blood pressure is well-controlled on indapamide alone: You can stop indapamide and start felodipine, but monitor closely for blood pressure rebound
• If blood pressure requires multiple agents: Consider keeping indapamide and adding felodipine, as guidelines recommend thiazide-like diuretics plus calcium channel blockers as effective combination therapy 1

Step 3: Monitor and Titrate

• Check blood pressure 2-4 weeks after the switch to assess response
• Felodipine can be titrated up to 10mg daily if needed for blood pressure control
• If switching (not adding), expect that blood pressure control may differ significantly from what was achieved with indapamide

Important Clinical Considerations

Why You Might Be Making This Switch

• Metabolic concerns: Indapamide is actually metabolically favorable compared to other diuretics 3, so if this is the reason, reconsider
• Electrolyte disturbances: If hypokalemia is the issue, felodipine avoids this entirely
• Edema from calcium channel blocker: If the patient was previously on a different calcium channel blocker and you switched TO indapamide for edema, now switching back to felodipine may recreate that problem

Common Pitfall to Avoid

• Do not assume 2.5mg indapamide = any specific dose of felodipine. The antihypertensive effect of indapamide 2.5mg daily reduces blood pressure by approximately 16% on average 2, but felodipine's effect at any given dose will depend entirely on the individual patient's vascular responsiveness to calcium channel blockade

Combination Therapy May Be Better

• Guidelines explicitly recommend combining thiazide-like diuretics (like indapamide) with calcium channel blockers (like felodipine) for patients requiring multiple agents 1
• Consider adding felodipine 5mg to the existing indapamide 2.5mg rather than switching, especially if blood pressure is not at goal