Metabolic considerations in the choice of therapy for the patient with hypertension. The objective of treating patients with hypertension is not simply to reduce blood pressure but rather to prevent the associated morbidity and mortality. Recent assessments of clinical trials have shown that while the risk of stroke is consistently lower with antihypertensive therapy, the same degree of success has not been demonstrated for coronary artery disease (CAD). Although there are many explanations of why we have not done as well in preventing CAD, one possibility is that the therapy used in clinical trials, primarily thiazide diuretics and beta-adrenoreceptor blockers, has increased the patient's risk of developing coronary atherosclerosis or lethal arrhythmias. Four classes of antihypertensive agents are recommended for initial therapy--thiazide diuretics, beta-adrenoreceptor blockers, angiotensin-converting enzyme (ACE) inhibitors, and calcium entry blockers. The metabolic effects of thiazide diuretics include electrolyte disturbances (hypokalemia, hypomagnesemia, and hyponatremia), dyslipidemia (increased triglycerides), abnormalities of glucose metabolism (hyperglycemia, hyperinsulinemia, and peripheral insulin resistance), and hyperuricemia. beta-Adrenoreceptor blockers have many of the same metabolic adverse reactions. beta-Adrenoreceptor blockers without intrinsic sympathomimetic activity (ISA) also cause dyslipidemias (lowered high-density lipoprotein cholesterol and increased triglycerides) and abnormalities of glucose metabolism (hyperglycemia, hyperinsulinemia, and peripheral insulin resistance). beta-Adrenoreceptor blockers with ISA and third-generation beta-blockers with selective partial agonist activity (celiprolol and dilevalol) do not cause dyslipidemia and to date do not appear to induce abnormalities in glucose metabolism. ACE inhibitors may decrease triglycerides and increase high-density lipoprotein cholesterol, and captopril may improve insulin sensitivity. Calcium entry blockers are metabolically neutral. 