Selected Antimuscarinics/Strong CYP3A4 Inhibitors
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.
Severe. 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:
Some medicines may prevent your body from processing your overactive bladder medicine correctly.
What might happen:
The levels of overactive bladder medicine in your blood may increase. You may notice an increase in side effects, such as blurred vision, dizziness, drowsiness, dry mouth, upset stomach, headache, dry eyes, or constipation.
What you should do about this interaction:
If you notice an increase in any side effects from your medicine, contact your healthcare professional (e.g. doctor or pharmacist). Your doctor may want to decrease the dose of your overactive bladder medicine while you are taking your other medicine.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.Enablex (darifenacin) US prescribing information. Warner Chilcott (US), LLC March, 2012.
2.Toviaz (fesoterodine fumarate) US prescribing information. Pfizer August, 2012.
3.Vesicare (solifenacin succinate) US prescribing information. Astella Pharma US, Inc. October, 2013.
4.Detrol (tolterodine tartrate) US prescribing information. Pfizer Inc. August, 2012.
5.Detrol LA (tolterodine tartrate) US prescribing information. Pfizer Inc. August, 2012.
6.US Food and Drug Administration (FDA). Drug Development and Drug Interactions: Table of Substrates, Inhibitors and Inducers. Available at: http://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources/D rugInteractionsLabeling/ucm093664.htm. Updated 08/05/2011.
7.Malhotra B, Dickins M, Alvey C, Jumadilova Z, Li X, Duczynski G, Gandelman K. Effects of the Moderate CYP3A4 Inhibitor, Fluconazole, on the Pharmacokinetics of Fesoterodine in Healthy Subjects. Br J Clin Pharmacol 2011 May 5.