Alfuzosin; Silodosin; Tamsulosin/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.
Medical warning:
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 slow down how quickly your liver processes your medicine.
What might happen:
The amount of alfuzosin, silodosin, or tamsulosin in your blood may increase. You may experience dizziness, fatigue, or fainting.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know right away that you are taking these medicines together. Tell your doctor if you experience any dizziness, fatigue, or fainting.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.Uroxatral (alfuzosin hydrochloride) US prescribing information. Sanofi-Synthelabo, Inc. December, 2010.
2.Rapaflo (silodosin) US prescribing information. Watson Laboratories, Inc. March, 2010.
3.Flomax (tamsulosin hydrochloride) US prescribing information. Boehringer Ingelheim Pharmaceuticals, Inc. July, 2011.
4.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.
5.Stribild (elvitegravir, cobicistat, emtricitabine, tenofovir) prescribing information. Gilead Sciences, Inc. August, 2012.
6.Troost J, Tatami S, Tsuda Y, Mattheus M, Mehlburger L, Wein M, Michel MC. Effects of strong CYP2D6 and 3A4 inhibitors, paroxetine and ketoconazole, on the pharmacokinetics and cardiovascular safety of tamsulosin. Br J Clin Pharmacol 2011 Aug;72(2):247-56.





