Diltiazem and Buspirone Interaction

Drug interaction information between Diltiazem and Buspirone.

Diltiazem and Buspirone have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Diltiazem and Buspirone. 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

Diltiazem

Calcium Channel Blocker

Drug B

Buspirone

Azapirone Anxiolytic

How They Interact

Diltiazem prevents the body from breaking down buspirone properly, which causes buspirone levels to rise significantly.

FDA Label Information

Buspirone : In nine healthy subjects, diltiazem significantly increased the mean buspirone AUC 5.5-fold and C max 4.1-fold compared to placebo. The T 1/2 and T max of buspirone were not significantly affected by diltiazem. Enhanced effects and increased toxicity of buspirone may be possible during concomitant administration with diltiazem.

Frequently Asked Questions

What SPL severity band is on file for Diltiazem + Buspirone?

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?

Diltiazem has 46 labeled pairs on file vs Buspirone's 17. In the minor band specifically: Diltiazem has 35 (also Pravastatin, Lovastatin, Cyclosporine, Carbamazepine); Buspirone has 15 (also Citalopram, Darunavir, Desvenlafaxine, Diphenoxylate/Atropine).

What mechanism field is on file for Diltiazem and Buspirone?

Diltiazem prevents the body from breaking down buspirone properly, which causes buspirone levels to rise significantly.

Diltiazem carries more major-labeled pairs than Buspirone

SPL source-record counts only. This page's band is minor · classes on file: Diltiazem (Calcium Channel Blocker); Buspirone (Azapirone Anxiolytic).

Diltiazem has 4 major-labeled pairs vs Buspirone's 0. This page itself is in the minor band, not the major band.

Diltiazem

4 major · 7 moderate · 35 minor · 46 total

Buspirone

0 major · 2 moderate · 15 minor · 17 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.