Alfuzosin; Silodosin; Tamsulosin/Grapefruit Juice
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug, changing your diet or commencing any course of treatment.
Medical warning:
Very important. A change in your diet, medicine, or dosage may be necessary. Promptly consult your doctor or pharmacist.
How the interaction occurs:
Grapefruit juice may increase the amount of your prostate medicine in your blood.
What might happen:
When your prostate medicine is taken with grapefruit juice, the grapefruit juice may cause the medicine to build up in your body. This may cause more side effects than it normally does, including dizziness, fatigue, or fainting.
What you should do about this interaction:
While you are taking this medicine, you should avoid eating grapefruit or drinking grapefruit juice. You may choose an alternative citrus beverage (such as orange juice). In the event that you are instructed by a healthcare professional (e.g., doctor, pharmacist, or dietitian) to eat grapefruit or drink grapefruit juice you should discuss with your doctor the effects of grapefruit on the blood levels of this medicine. These effects can occur even if grapefruit is not consumed at the same time of the silodosin dose. This interaction may occur at any time in your treatment with silodosin if grapefruit or grapefruit juice is consumed. Let your doctor know if you have any problems with 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.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.
5.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.
