Lorazepam; Mexazolam/Valproate 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:

Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Valproate may slow down how quickly your liver processes lorazepam or mexazolam.

What might happen:

You may notice increased effects from your lorazepam or mexazolam, including sluggishness and disorientation. You may lose consciousness.

What you should do about this interaction:

Let your healthcare professionals (e.g. doctor and pharmacist) know that you are taking these medicines together. If you notice increased effects from your lorazepam, such as sluggishness and disorientation, contact your doctor. It may be necessary to change the dose of your lorazepam.Your healthcare professionals may already be aware of this 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.Ativan (lorazepam injection) US prescribing information. Biovail Laboratories International SRL April 27, 2017.
  • 2.Ativan (lorazepam tablets) US prescribing information. Biovail Pharmaceuticals April, 2007.
  • 3.Anderson GD, Gidal BE, Kantor ED, Wilensky AJ. Lorazepam-valproate interaction: studies in normal subjects and isolated perfused rat liver. Epilepsia 1994 Jan-Feb;35(1):221-5.
  • 4.Samara EE, Granneman RG, Witt GF, Cavanaugh JH. Effect of valproate on the pharmacokinetics and pharmacodynamics of lorazepam. J Clin Pharmacol 1997 May;37(5):442-50.
  • 5.von Moltke LL, Manis M, Harmatz JS, Poorman R, Greenblatt DJ. Inhibition of acetaminophen and lorazepam glucuronidation in vitro by probenecid. Biopharm Drug Dispos 1993 Mar;14(2):119-30.

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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.