Metrizamide/Phenothiazines 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:

The cause of the interaction is not known.

What might happen:

You may experience an increased risk for seizures.

What you should do about this interaction:

Contact your healthcare professionals (e.g. doctor or pharmacist) as soon as possible about using these two medicines together. They may already be aware of this interaction and may be monitoring you for it. It may be necessary to stop your dose of phenothiazine at least 48 hours prior to giving you metrizamide. Do not start, stop, or change the dosage of any medicine before checking with them first.

  • 1.Hindmarsh T, Grepe A, Widen L. Metrizamide-phenothiazine interaction. Report of a case with seizures following myelography. Acta Radiol Diagn (Stockh) 1975 Mar;16(2):129-34.
  • 2.Hindmarsh T. Lumbar myelography with meglumine iocarmate and metrizamide. Acta Radiol Diagn (Stockh) 1975 May;16(3):209-22.
  • 3.Gonsette RE, Brucher JM. Potentiation of Amipaque epileptogenic activity by neuroleptics. Neuroradiology 1977 Aug 25;14(1):27-30.
  • 4.Hauge O, Falkenberg H. Neuropsychologic reactions and other side effects after metrizamide myelography. AJR Am J Roentgenol 1982 Aug;139(2):357-60.
  • 5.Maly P, Olivecrona H, Almen T, Golman K. Interaction between chlorpromazine and intrathecally injected non-ionic contrast media in non-anaesthetized rabbits. Neuroradiology 1984;26(3):235-40.
  • 6.Thorazine (chlorpromazine) US prescribing information. GlaxoSmithKline April, 2002.
  • 7.Hanus PM. Metrizamide: a review with emphasis on drug interactions. Am J Hosp Pharm 1980 Apr;37(4):510-3.
  • 8.Chlorpromazine hydrochloride US prescribing information. Sandoz, Inc. March, 2011.

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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.