Choice of drug treatment for elderly hypertensive patients. It is generally agreed that moderate and severe hypertension in the elderly should be treated, but it is not clear which drug or drugs are most appropriate. Thiazide diuretics are inexpensive and effective, but they are associated with metabolic side effects that are becoming less acceptable as newer agents become available. Beta blockers are effective, but can be associated with central nervous system side effects and are often contraindicated by coexisting disease. Recently, attention has been focused on the newer agents, including calcium antagonists and angiotensin-converting enzyme inhibitors. The advantage of calcium antagonists is that they do not produce metabolic side effects. However, they are expensive and may cause vasodilatory side effects. The angiotensin-converting enzyme inhibitors are effective and relatively free of side effects and may be particularly useful for elderly hypertensive patients with congestive heart failure. 