Thiazides have been a cornerstone in most trials of antihypertensive therapy. Their adverse metabolic consequences include renal potassium loss leading to hypokalemia, hyperuricemia from uric acid retention, carbohydrate intolerance, and hyperlipidemia. The current U.S. Joint National Committee (JNC-7) guidelines suggest starting with thiazide diuretics because of their proven efficacy in lowering mortality and morbidity in large clinical trials. Other agents are considered if there are comorbidities such as diabetes or CAD.