Drug interactions with valsartan can alter the levels of some drugs in your blood and lower your blood pressure too much, among other things. Some of the drugs that valsartan can potentially interact with include diuretics such as hydrochlorothiazide, furosemide, and torsemide; and potassium-sparing diuretics such as spironolactone and amiloride. Also, if you take valsartan along with potassium supplements, the levels of potassium in your blood may become too high -- which can cause serious problems. Ask you healthcare provider or pharmacist about any valsartan drug interactions that may apply to you.
When taking valsartan with a diuretic, your blood pressure may decrease too much. This is more likely to occur when valsartan is first started. In order to decrease the chances of this interaction, your healthcare provider may change the dosages of either medicine, start you on a lower dose of valsartan, and/or monitor you more closely.
Potassium Supplements
If you are taking a potassium supplement and valsartan, the levels of potassium in your blood may become too high. This can cause serious problems. Talk with your healthcare provider about using potassium and valsartan together.