COMT Inhibitors/Selected MAOIs Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Very Serious. These medicines may interact and cause very harmful effects and are usually not taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

When these two medicines are taken together, your body may not be able to process certain body chemicals (e.g. epinephrine) properly.

What might happen:

You may experience a faster heart rate and/or an increase in blood pressure.

What you should do about this interaction:

Contact your healthcare professionals (e.g. doctor or pharmacist) as soon as possible about taking these two medicines together. They may already be aware of this drug interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.

  • 1.Comtess (entacapone) UK summary of product characteristics. Orion Pharma, UK September 16, 1998.
  • 2.Tasmar (tolcapone) US prescribing information. Valeant Pharmaceuticals International May, 2013.
  • 3.Comtan (entacapone) US prescribing information. Orion Corporation February, 2016.
  • 4.Comtan (entacapone) Canadian prescribing information. Novartis Pharmaceuticals Canada Inc. March, 2006.
  • 5.Tasmar (tolcapone) UK summary of product characteristics. Valeant Pharmaceuticals Ltd. Januar 11, 2006.
  • 6.Eldepryl (selegiline) US prescribing information. Somerset Pharmaceuticals February, 1997.
  • 7.Emsam (selegiline) US prescribing information. Somerset August, 2007.
  • 8.Ramsay RR, Dunford C, Gillman PK. Methylene blue and serotonin toxicity: inhibition of monoamine oxidase A (MAO A) confirms a theoretical prediction. Br J Pharmacol 2007 Nov;152(6):946-51.
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  • 10.Ongentys (opicapone) Middle East prescribing information. Bial-Portela and Ca, S.A. 2018.
  • 11.Ongentys (opicapone) US prescribing information. Neurocrine Biosciences, Inc. April, 2020.
  • 12.Surmaitis RM, Nappe TM, Cook MD. Serotonin syndrome associated with therapeutic metaxalone in a patient with cirrhosis. Am J Emerg Med 2016 Feb;34(2):346.e5-6.
  • 13.Skelaxin (metaxalone) US prescribing information. Pfizer Laboratories Div Pfizer Inc. January, 2024.

Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, except as may be authorized by the applicable terms of use.

CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.