Citalopram and Warfarin Interaction

Drug interaction information between Citalopram and Warfarin.

Citalopram and Warfarin have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Citalopram and Warfarin. 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

Citalopram

Selective Serotonin Reuptake Inhibitor (SSRI)

Drug B

Warfarin

Vitamin K Antagonist (Anticoagulant)

How They Interact

Citalopram can change how warfarin works in your body, which may affect how quickly your blood is able to clot.

FDA Label Information

For patients taking warfarin, carefully monitor the international normalized ratio [see Warning and Precautions (5.4) ].

Warfarin Also Interacts With

View all Warfarin interactions →

Frequently Asked Questions

What SPL severity band is on file for Citalopram + Warfarin?

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

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

Warfarin has 163 labeled pairs on file vs Citalopram's 9. In the moderate band specifically: Citalopram has 2 (also Phenelzine); Warfarin has 28 (also Ibuprofen, Aspirin, Diclofenac, Desvenlafaxine).

What mechanism field is on file for Citalopram and Warfarin?

Citalopram can change how warfarin works in your body, which may affect how quickly your blood is able to clot.

Citalopram carries more major-labeled pairs than Warfarin

SPL source-record counts only. This page's band is moderate · classes on file: Citalopram (Selective Serotonin Reuptake Inhibitor (SSRI)); Warfarin (Vitamin K Antagonist (Anticoagulant)).

Citalopram has 3 major-labeled pairs vs Warfarin's 2. This page itself is in the moderate band, not the major band.

Citalopram

3 major · 2 moderate · 4 minor · 9 total

Warfarin

2 major · 28 moderate · 133 minor · 163 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.