Lorazepam/Valproate
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.
What might happen:
You may notice increased effects from your lorazepam, 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.
References:
1.Ativan (lorazepam injection) US prescribing information. Baxter Healthcare Corporation November, 2006.
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.
