Dextromethorphan and Phentermine interaction
Dextromethorphan and Phentermine: the Phentermine prescribing label mention this combination without an instruction to avoid it or change the dose.
Mentioned, no instruction to avoid. Worth knowing; rarely a reason to change anything on its own.
What the FDA labels say
From the Phentermine (Phentermine hydrochloride) label · effective 2026-08-17
The safety and efficacy of combination therapy with phentermine and any other drug products for weight loss including prescribed drugs, over-the-counter preparations, and herbal products, or serotonergic agents such as selective serotonin reuptake inhibitors (e.g., fluoxetine, sertraline, fluvoxamine, paroxetine), have not been established.
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.