Efavirenz and Simvastatin Interaction

Drug interaction information between Efavirenz and Simvastatin.

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

FDA drug labeling documents a minor-severity interaction between Efavirenz 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

Efavirenz

NNRTI / NRTI Combination

Drug B

Simvastatin

HMG-CoA Reductase Inhibitor (Statin)

How They Interact

This combination causes the cholesterol medicine to be cleared from your body faster than usual.

FDA Label Information

HMG-CoA reductase inhibitors: Atorvastatin Pravastatin Simvastatin ↓ atorvastatin * ↓ pravastatin * ↓ simvastatin * Plasma concentrations of atorvastatin, pravastatin, and simvastatin decreased.

Frequently Asked Questions

What SPL severity band is on file for Efavirenz/Emtricitabine/Tenofovir + 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 Efavirenz's 32. In the minor band specifically: Efavirenz has 29 (also Atorvastatin, Sertraline, Bupropion, Famotidine); Simvastatin has 21 (also Fenofibrate, Ketoconazole, Erythromycin, Clarithromycin).

What mechanism field is on file for Efavirenz/Emtricitabine/Tenofovir and Simvastatin?

This combination causes the cholesterol medicine to be cleared from your body faster than usual.

Simvastatin carries more major-labeled pairs than Efavirenz

SPL source-record counts only. This page's band is minor · classes on file: Efavirenz (NNRTI / NRTI Combination); Simvastatin (HMG-CoA Reductase Inhibitor (Statin)).

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

Efavirenz

0 major · 3 moderate · 29 minor · 32 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.