Lisdexamfetamine and Phenelzine interaction
Lisdexamfetamine and Phenelzine: 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 Lisdexamfetamine (Lisdexamfetamine Dimesylate) label · effective 2026-05-22
• Patients 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 crisis [see Warnings and Precautions (5.7) and Drug Interactions (7.1) ] .
• Use with monoamine oxidase (MAO) inhibitor, or within 14 days of the last MAO inhibitor dose ( 4 , 7.1 )
• Serotonin Syndrome: Increased risk when co-administered with serotonergic agents (e.g., SSRIs, SNRIs, triptans), but also during overdosage situations.
Concomitant use of lisdexamfetamine dimesylate with MAOI drugs is contraindicated [see Contraindications (4) ] .
Discontinue treatment with lisdexamfetamine dimesylate and any concomitant serotonergic agents immediately if symptoms of serotonin syndrome occur, and initiate supportive symptomatic treatment.
From the Phenelzine (phenelzine sulfate) label · effective 2026-05-21
The potentiation of sympathomimetic substances and related compounds by MAO inhibitors may result in hypertensive crises (see WARNINGS ).
Therefore, patients being treated with phenelzine sulfate should not take sympathomimetic drugs (including amphetamines, cocaine, methylphenidate, dopamine, epinephrine, and norepinephrine) or related compounds (including methyldopa, L-dopa, L-tryptophan, L-tyrosine, and phenylalanine).
Also, they should not be given cocaine or local anesthesia containing sympathomimetic vasoconstrictors.
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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.