Sulfasalazine and Sofosbuvir/Velpatasvir Interaction

Drug interaction information between Sulfasalazine and Sofosbuvir/Velpatasvir.

Sulfasalazine and Sofosbuvir/Velpatasvir have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Sulfasalazine and Sofosbuvir/Velpatasvir. 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

Sulfasalazine

Disease-Modifying Antirheumatic Drug (DMARD)

Drug B

Sofosbuvir/Velpatasvir

NS5B/NS5A Inhibitor (HCV)

How They Interact

This medicine interferes with a protein that transports sulfasalazine, which could cause the levels of sulfasalazine in your body to rise.

FDA Label Information

Coadministration of VOSEVI with BCRP substrates (e.g., methotrexate, mitoxantrone, imatinib, irinotecan, lapatinib, rosuvastatin, sulfasalazine, topotecan) is not recommended [see Clinical Pharmacology (12.3) ].

Frequently Asked Questions

What SPL severity band is on file for Sulfasalazine + Sofosbuvir/Velpatasvir?

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?

Sofosbuvir/Velpatasvir has 33 labeled pairs on file vs Sulfasalazine's 7. In the moderate band specifically: Sulfasalazine has 2 (also Lidocaine Topical); Sofosbuvir/Velpatasvir has 10 (also Pravastatin, Methotrexate, Cyclosporine, Carbamazepine).

What mechanism field is on file for Sulfasalazine and Sofosbuvir/Velpatasvir?

This medicine interferes with a protein that transports sulfasalazine, which could cause the levels of sulfasalazine in your body to rise.

Sofosbuvir/Velpatasvir carries more major-labeled pairs than Sulfasalazine

SPL source-record counts only. This page's band is moderate · classes on file: Sulfasalazine (Disease-Modifying Antirheumatic Drug (DMARD)); Sofosbuvir/Velpatasvir (NS5B/NS5A Inhibitor (HCV)).

Sofosbuvir/Velpatasvir has 3 major-labeled pairs vs Sulfasalazine's 0. This page itself is in the moderate band, not the major band.

Sulfasalazine

0 major · 2 moderate · 5 minor · 7 total

Sofosbuvir/Velpatasvir

3 major · 10 moderate · 20 minor · 33 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.