Sitagliptin and metformin and Zonisamide interaction
Sitagliptin and metformin and Zonisamide: the Sitagliptin and metformin prescribing label flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Sitagliptin and metformin (JANUMET XR) label · effective 2026-08-11
Risk factors for metformin-associated lactic acidosis include renal impairment, concomitant use of certain drugs (e.g., carbonic anhydrase inhibitors such as topiramate), age 65 years old or greater, having a radiological study with contrast, surgery and other procedures, hypoxic states (e.g., acute congestive heart failure), excessive alcohol intake, hepatic…
Table 4 presents clinically significant drug interactions with JANUMET XR: Table 4: Clinically Significant Drug Interactions with JANUMET XR Carbonic Anhydrase Inhibitors Clinical Impact: Carbonic anhydrase inhibitors frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis.
Carbonic anhydrase inhibitors may increase risk of lactic acidosis.
Examples: Topiramate, zonisamide, acetazolamide or dichlorphenamide.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.