Metformin/Pioglitazone and Topiramate Interaction

Drug interaction information between Metformin/Pioglitazone and Topiramate.

Metformin/Pioglitazone and Topiramate have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Metformin/Pioglitazone and Topiramate. 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

Metformin/Pioglitazone

Biguanide / TZD Combination

Drug B

Topiramate

Anticonvulsant

How They Interact

Topiramate can lower the levels of pioglitazone in your body, which might make it work less effectively. It can also cause a change in your blood's acid levels.

FDA Label Information

( 7.6 ) Topiramate may decrease pioglitazone concentrations. 7.3 Carbonic Anhydrase Inhibitors Topiramate or other carbonic anhydrase inhibitors (e.g., zonisamide, acetazolamide or dichlorphenamide) frequently causes a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. 7.8 Topiramate A decrease in the exposure of pioglitazone and its active metabolites were noted with concomitant administration of pioglitazone and topiramate [see Clinical Pharmacology (12.3) ] .

Metformin/Pioglitazone Also Interacts With

View all Metformin/Pioglitazone interactions →

Frequently Asked Questions

What SPL severity band is on file for Metformin/Pioglitazone + Topiramate?

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?

Topiramate has 30 labeled pairs on file vs Metformin/Pioglitazone's 10. In the minor band specifically: Metformin/Pioglitazone has 7 (also Metformin, Pioglitazone, Rifampin, Gemfibrozil); Topiramate has 27 (also Hydrochlorothiazide, Amitriptyline, Pioglitazone, Carbamazepine).

What mechanism field is on file for Metformin/Pioglitazone and Topiramate?

Topiramate can lower the levels of pioglitazone in your body, which might make it work less effectively. It can also cause a change in your blood's acid levels.

Topiramate's labeled portfolio outnumbers Metformin/Pioglitazone

SPL source-record counts only. This page's band is minor · classes on file: Metformin/Pioglitazone (Biguanide / TZD Combination); Topiramate (Anticonvulsant).

Metformin/Pioglitazone

0 major · 3 moderate · 7 minor · 10 total

Topiramate

0 major · 3 moderate · 27 minor · 30 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.