Amphetamine and dextroamphetamine and Phentermine interaction
Amphetamine and dextroamphetamine and Phentermine: 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 Amphetamine and dextroamphetamine (Adderall XR) label · effective 2026-04-30
Hypersensitivity reactions such as angioedema and anaphylactic reactions have been reported in patients treated with other amphetamine products [see Adverse Reactions ( 6.2 )] . taking monoamine oxidase inhibitors (MAOIs), or within 14 days of stopping MAOIs (including MAOIs such as linezolid or intravenous methylene blue), because of an increased risk of hypertensive…
Tricyclic Antidepressants Clinical Impact May enhance the activity of tricyclic or sympathomimetic agents causing striking and sustained increases in the concentration of d-amphetamine in the brain; cardiovascular effects can be potentiated.
From the Phentermine (Phentermine hydrochloride) label · effective 2026-08-17
Risk of Abuse and Dependence Phentermine is related chemically and pharmacologically to amphetamine (d- and d l l-amphetamine) and other related stimulant drugs that have been extensively abused.
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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.