Can hyzaar and grapefruit be used together

Concha,

Thanks for your question.

Hyzaar is a blood pressure medication that is a combination of an Angiotensin II blocker, cozaar, and a diuretic, hydrochlorthiazide.  The cozaar works by causing blood vessels to dilate in addition to causing the kidneys to lose more water and salts.  Both actions result in lower blood pressure.  The diuretic causes water loss in addition to having a direct effect on blood pressure.

Grapefruit juice has been found to reduce the action an enzyme in the intestine, which breaks down various drugs to forms that are ineffective.  When this enzyme is reduced, drug levels can rise.  In some cases this can result in a higher incidence of side effects, which has been found in statin medication, resulting in more patients experiencing muscle symptoms.

My research has revealed that Hyzaar can be affected by grapefruit juice, which means that levels of this drug can increase if taken with grapefruit juice.  The point in question is: how much grapefruit juice does it take to significantly affect medication you are taking.  Many doctors feel that modest amount of this juice (4 oz) should pose no problem, but quantities in excess of a quart a day can change drug levels significantly.  This has not been studied in detail. 

You should certainly discuss this with your physician.  One option is to switch to another citrus juice that will not affect your medication, such as orange juice.   

I hope this has been helpful.

Martin Cane, M.D. 

can hyzaar and grapefruit juice be used together