Trimethoprim and Pioglitazone Interaction

Drug interaction information between Trimethoprim and Pioglitazone.

Trimethoprim and Pioglitazone have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Trimethoprim and Pioglitazone. 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

Trimethoprim

Dihydrofolate Reductase Inhibitor

Drug B

Pioglitazone

Thiazolidinedione

How They Interact

Trimethoprim slows down the liver's ability to break down pioglitazone. This can make the blood sugar-lowering effect of the medicine stronger than intended.

FDA Label Information

Sulfamethoxazole and trimethoprim potentiates the effect of oral hypoglycemics that are metabolized by CYP2C8 (e.g., pioglitazone, repaglinide, and rosiglitazone) or CYP2C9 (e.g., glipizide and glyburide) or eliminated renally via OCT2 (e.g., metformin).

Frequently Asked Questions

What SPL severity band is on file for Trimethoprim + Pioglitazone?

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?

Trimethoprim has 22 labeled pairs on file vs Pioglitazone's 10. In the minor band specifically: Trimethoprim has 18 (also Metformin, Glipizide, Warfarin, Methotrexate); Pioglitazone has 9 (also Rifampin, Gemfibrozil, Abiraterone, Dapagliflozin).

What mechanism field is on file for Trimethoprim and Pioglitazone?

Trimethoprim slows down the liver's ability to break down pioglitazone. This can make the blood sugar-lowering effect of the medicine stronger than intended.

Trimethoprim's labeled portfolio outnumbers Pioglitazone

SPL source-record counts only. This page's band is minor · classes on file: Trimethoprim (Dihydrofolate Reductase Inhibitor); Pioglitazone (Thiazolidinedione).

Trimethoprim

1 major · 3 moderate · 18 minor · 22 total

Pioglitazone

1 major · 0 moderate · 9 minor · 10 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.