Diazepam/Fluconazole; Voriconazole 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:
Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
Your antifungal medicine may slow down your body's ability to process diazepam.
What might happen:
The levels of diazepam may build up in your body. The effects of the diazepam may increase.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. If you notice an increase in the effects of your diazepam such as drowsiness, contact your doctor. The dose of your diazepam may need to be changed.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.Saari TI, Laine K, Bertilsson L, Neuvonen PJ, Olkkola KT. Voriconazole and fluconazole increase the exposure to oral diazepam. Eur J Clin Pharmacol 2007 Oct;63(10):941-9.
- 2.Valium (diazepam) US prescribing information. Roche Products Inc December, 2016.
- 3.Diflucan (fluconazole) US prescribing information. Pfizer Inc. January, 2023.
- 4.Vfend (voriconazole) US prescribing information. Pfizer Inc. October, 2022.
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- 8.Vanakoski J, Mattila MJ, Vainio P, Idanpaan-Heikkila JJ, Tornwall M. 150 mg fluconazole does not substantially increase the effects of 10 mg midazolam or the plasma midazolam concentrations in healthy subjects. Int J Clin Pharmacol Ther 1995 Sep;33(9):518-23.
- 9.von Moltke LL, Greenblatt DJ, Schmider J, Duan SX, Wright CE, Harmatz JS, Shader RI. Midazolam hydroxylation by human liver microsomes in vitro: inhibition by fluoxetine, norfluoxetine, and by azole antifungal agents. J Clin Pharmacol 1996 Sep;36(9):783-91.
- 10.Saari TI, Laine K, Leino K, Valtonen M, Neuvonen PJ, Olkkola KT. Effect of voriconazole on the pharmacokinetics and pharmacodynamics of intravenous and oral midazolam. Clin Pharmacol Ther 2006 Apr; 79(4):362-70.
- 11.US Food and Drug Administration (FDA). Drug Development and Drug Interactions: Table of Substrates, Inhibitors and Inducers. Available at: https://www.fda.gov/drugs/drug-interactions-labeling/drug-development-and -drug-interactions-table-substrates-inhibitors-and-inducers. Updated 11/14/2017.
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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.