Zonisamide and Metformin Interaction

Drug interaction information between Zonisamide and Metformin.

Zonisamide and Metformin have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Zonisamide and Metformin. 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

Zonisamide

Anticonvulsant (Sulfonamide)

Drug B

Metformin

Biguanide

How They Interact

Zonisamide can cause your blood to become too acidic, which increases the risk of a rare but serious side effect when combined with metformin.

FDA Label Information

Examples: Topiramate, zonisamide, acetazolamide or dichlorphenamide.

Frequently Asked Questions

What SPL severity band is on file for Zonisamide + Metformin?

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?

Metformin has 27 labeled pairs on file vs Zonisamide's 13. In the minor band specifically: Zonisamide has 10 (also Carbamazepine, Empagliflozin, Empagliflozin/Linagliptin, Linagliptin); Metformin has 17 (also Topiramate, Dolutegravir, Ranolazine, Cimetidine).

What mechanism field is on file for Zonisamide and Metformin?

Zonisamide can cause your blood to become too acidic, which increases the risk of a rare but serious side effect when combined with metformin.

Metformin's labeled portfolio outnumbers Zonisamide

SPL source-record counts only. This page's band is minor · classes on file: Zonisamide (Anticonvulsant (Sulfonamide)); Metformin (Biguanide).

Zonisamide

0 major · 3 moderate · 10 minor · 13 total

Metformin

0 major · 10 moderate · 17 minor · 27 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.