Isradipine and Hydrochlorothiazide Interaction

Drug interaction information between Isradipine and Hydrochlorothiazide.

Isradipine and Hydrochlorothiazide have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Isradipine and Hydrochlorothiazide. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Isradipine

Calcium Channel Blocker

Drug B

Hydrochlorothiazide

Thiazide Diuretic

How They Interact

These medicines work in different ways to lower blood pressure, which can lead to a stronger effect when taken together.

FDA Label Information

Hydrochlorothiazide: A study in normal healthy volunteers has shown that concomitant administration of isradipine and hydrochlorothiazide does not result in altered pharmacokinetics of either drug. In a study in hypertensive patients, addition of isradipine to existing hydrochlorothiazide therapy did not result in any unexpected adverse effects, and isradipine had an additional antihypertensive effect.

Frequently Asked Questions

What SPL severity band is on file for Isradipine + Hydrochlorothiazide?

Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Hydrochlorothiazide has 31 labeled pairs on file vs Isradipine's 9. In the minor band specifically: Isradipine has 8 (also Propranolol, Warfarin, Digoxin, Nitroglycerin); Hydrochlorothiazide has 27 (also Losartan, Spironolactone, Propranolol, Lithium).

What mechanism field is on file for Isradipine and Hydrochlorothiazide?

These medicines work in different ways to lower blood pressure, which can lead to a stronger effect when taken together.

Hydrochlorothiazide carries more major-labeled pairs than Isradipine

SPL source-record counts only. This page's band is minor · classes on file: Isradipine (Calcium Channel Blocker); Hydrochlorothiazide (Thiazide Diuretic).

Hydrochlorothiazide has 3 major-labeled pairs vs Isradipine's 1. This page itself is in the minor band, not the major band.

Isradipine

1 major · 0 moderate · 8 minor · 9 total

Hydrochlorothiazide

3 major · 1 moderate · 27 minor · 31 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.