Phendimetrazine and Phenelzine interaction
Phendimetrazine 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 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.
From the Phendimetrazine (PHENDIMETRAZINE TARTRATE) label · effective 2025-12-19
…coronary artery disease, stroke, arrhythmias, congestive heart failure, uncontrolled hypertension, pulmonary hypertension) • During or within 14 days following the administration of monoamine oxidase inhibitors • Hyperthyroidism • Glaucoma • Agitated states • History of drug abuse • Pregnancy (see PRECAUTIONS, Pregnancy ) • Nursing • Use in combination with other…
Drug Interactions Monoamine Oxidase Inhibitors Use of phendimetrazine tartrate is contraindicated during or within 14 days following the administration of monoamine oxidase inhibitors because of the risk of hypertensive crisis.
Use of phendimetrazine tartrate within 14 days following the administration of monoamine oxidase inhibitors may result in a hypertensive crisis.
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.