Drug Interaction Report

Diethylpropion and Iproniazid: Interaction Details

A pharmacist-reviewed analysis of the Diethylpropion and Iproniazid interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Diethylpropion

Tenuate Tenuate® Tenuate® Dospan Tepanil®
+

Iproniazid

No brand names on record
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Contraindicated
These should generally not be used together.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Of 21 documented Diethylpropion interactions, 18 are rated contraindicated — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
rapid
Evidence
probable
Severity
Contraindicated

What happens

Hypertensive crisis (headache, hyperpyrexia, hypertension)

Interaction Deep Dive

Amphetamines and amphetamine-like agents cause the release of norepinephrine, and the use of MAO inhibitors results in more norepinephrine being made available at nerve receptor sites through inhibition of catecholamine degradation; concurrent use leads to greater amounts of norepinephrine which increases sympathetic activity1. Coadministration of indirect-acting sympathomimetics and monoamine oxidase inhibitors (MAOIs) has resulted in severe hypertension and hyperpyrexia 2345. Because diethylpropion is capable of causing elevated blood pressure and central nervous system stimulation, the concurrent use or use within 14 days following the administration of a MAOI is contraindicated 6.

Why it happens (mechanism)

Increased norepinephrine availability

Common questions

Can I take Diethylpropion and Iproniazid together?

Hypertensive crisis (headache, hyperpyrexia, hypertension) Always confirm with your pharmacist or prescriber before making any change.

How serious is the Diethylpropion and Iproniazid interaction?

It is rated contraindicated. These should generally not be used together.

How quickly could this interaction happen?

The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.

How strong is the evidence for this interaction?

The evidence is graded "probable". Good supporting evidence, though not definitively proven.

Questions for your pharmacist

  • Does my dose of Diethylpropion or Iproniazid need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there a safer alternative to one of these medications for me?

References (6)

  1. Gilman AG, Rall TW, Nies AS, et alGilman AG, Rall TW, Nies AS, et al (Eds): Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th. Macmillan Publishing Co, New York, NY, 1990.
  2. Krisko I, Lewis E, & Johnson JE: Severe hyperpyrexia due to tranylcypromine-amphetamine toxicity. Ann Intern Med 1969; 70:559-564. PubMed
  3. Lloyd JTA & Walker DRH: Death after combined dexamphetamine and phenelzine (letter). Br Med J 1965; 2:168-169. DOI
  4. Mason A: Fatal reaction associated with tranylcypromine and methylamphetamine (letter). Lancet 1962; 1:1073. DOI
  5. Dally PJ: Fatal reaction associated with tranylcypromine and methylamphetamine (letter). Lancet 1962; 1:1235-1236. DOI
  6. Product Information: Tenuate(R), diethylpropion. Hoechst Marion Roussel, Inc. Kansas City, MO, 1997. DailyMed
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Diethylpropion

Keep reading about Diethylpropion

All Diethylpropion interactions (21) Diethylpropion drug information
Also serious with: Brofaromine Clorgyline Furazolidone Linezolid Injection
Iproniazid

Keep reading about Iproniazid

All Iproniazid interactions (14)
Also serious with: Amitriptyline Sertraline Deutetrabenazine Entacapone
Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Diethylpropion + Activated Charcoal Ephedra Peyote Rauvolfia Vomitoria Sida Cordifolia 1,3-dmaa 1,3-dmba 1,4-dmaa + 53 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.