Diovan has a drug interaction with potassium-sparing diuretics. When Diovan is taken with potassium-sparing diuretics, it can increase the risk of hyperkalemia, which is a condition characterized by high levels of potassium in the blood. This can be a serious and potentially life-threatening condition, so it is important to monitor potassium levels closely when taking Diovan with potassium-sparing diuretics.