Nortriptyline and Phentermine interaction

Nortriptyline and Phentermine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.

Moderate

Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.

What the FDA labels say

From the Nortriptyline (PAMELOR) label · effective 2024-12-04

Moderate

Close supervision and careful adjustment of the dosage are required when Pamelor is used with other anticholinergic drugs and sympathomimetic drugs.

Drug interactionsby drug classView label on DailyMed

From the Phentermine (Phentermine hydrochloride) label · effective 2026-08-17

Minor

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.

Warnings and precautionsby drug classView label on DailyMed

Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.

Open in the checker

Not 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.