It may also be used to prevent further damage after a heart attack. It works by relaxing the blood vessels, which decreases blood pressure and the amount of work the heart has to do. Rates of adverse effects are based on a comparison versus placebo in people with heart failure. Most common side effects include dizziness diovan 160 mg over the counter (17% vs 9% ), low blood pressure (7% vs 2%), and diarrhea (5% vs 4%). Less common side effects include joint pain, fatigue, and back pain (all 3% vs 2%). Valsartan has reduced rates of mortality and heart failure hospitalisations when used alone or in combination with beta-blockers in the treatment of heart failure.