Ephedrine and Phentermine and topiramate interaction
Ephedrine and Phentermine and topiramate: both prescribing labels 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 Phentermine and topiramate label · effective 2026-05-18
…(8.1) ] With glaucoma [see Warnings and Precautions (5.3) ] With hyperthyroidism Taking or within 14 days of stopping a monoamine oxidase inhibitors [see Drug Interactions (7) ] With known hypersensitivity to phentermine, topiramate or any of the excipients in phentermine and topiramate extended-release capsules, or idiosyncrasy to the sympathomimetic amines.
Known hypersensitivity to any component of phentermine and topiramate extended-release capsules or idiosyncrasy to sympathomimetic amines ( 4 )
From the Ephedrine (Ephedrine Sulfate) label · effective 2026-03-17
• Pr e ssor Effect with Concomitant Oxytocic Drugs : Pressor effect of sympathomimetic pressor amines is potentiated (5.1)
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.