SN instructed that Valsartan is an angiotensin receptor antagonist, with particularly high affinity for the type I angiotensin receptor. Call your doctor right away if you notice any of these side effects: allergic reaction: itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing, change in how much or how often you urinate, bloody or cloudy urine, confusion, weakness, uneven heartbeat, trouble breathing, numbness in your hands, feet, or lips, lightheadedness, dizziness, fainting, rapid weight gain, swelling in your hands, ankles, or feet.