Leflunomide and Simvastatin Interaction

Drug interaction information between Leflunomide and Simvastatin.

Leflunomide and Simvastatin have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Leflunomide and Simvastatin. 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

Leflunomide

Disease-Modifying Antirheumatic Drug (DMARD)

Drug B

Simvastatin

HMG-CoA Reductase Inhibitor (Statin)

How They Interact

Leflunomide can block the proteins that help your body get rid of simvastatin, which may cause the drug to reach higher levels than normal.

FDA Label Information

For other substrates of BCRP (e.g., mitoxantrone) and drugs in the OATP family (e.g., methotrexate, rifampin), especially HMG-Co reductase inhibitors (e.g., atorvastatin, nateglinide, pravastatin, repaglinide, and simvastatin), consider reducing the dose of these drugs and monitor patients closely for signs and symptoms of increased exposures to the drugs while patients are taking leflunomide [see Clinical Pharmacology (12.3) ].

Frequently Asked Questions

What SPL severity band is on file for Leflunomide + Simvastatin?

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?

Simvastatin has 41 labeled pairs on file vs Leflunomide's 20. In the minor band specifically: Leflunomide has 20 (also Atorvastatin, Rosuvastatin, Furosemide, Duloxetine); Simvastatin has 21 (also Fenofibrate, Ketoconazole, Erythromycin, Clarithromycin).

What mechanism field is on file for Leflunomide and Simvastatin?

Leflunomide can block the proteins that help your body get rid of simvastatin, which may cause the drug to reach higher levels than normal.

Simvastatin carries more major-labeled pairs than Leflunomide

SPL source-record counts only. This page's band is minor · classes on file: Leflunomide (Disease-Modifying Antirheumatic Drug (DMARD)); Simvastatin (HMG-CoA Reductase Inhibitor (Statin)).

Simvastatin has 11 major-labeled pairs vs Leflunomide's 0. This page itself is in the minor band, not the major band.

Leflunomide

0 major · 0 moderate · 20 minor · 20 total

Simvastatin

11 major · 9 moderate · 21 minor · 41 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.