Overview of Hypertension Pharmacologic Treatments

The general approach to pharmacologic treatment of hypertension is outlined in JNC-VI. Treatment is stratified as a function of blood pressure stage (high normal: 130-139/85-89; stage 1: 140-159/90-99; and stage 2 and 3: ≥160/≥100 mmHg) and three levels of risk. Because age greater than 60 years is considered as one component of cardiovascular risk, all older hypertensive patients fall into the middle risk group (risk group B) at a minimum.

For those with high-normal and stage 1 hypertension with no additional cardiovascular risk factors, 6-month trial of nonpharmacologic therapy is warranted. If a 6-month trial of nonpharmacologic treatment fails to produce the desired reduction in blood pressure, pharmacologic therapy should be initiated while nonpharmacologic treatments are continued. Older patients who initially present with more severe hypertension (stage 2 or 3), as well as those with diabetes or additional cardiovascular risk factors or evidence of target organ damage (risk group C), should receive pharmacologic therapy initiated concurrently with nonpharmacologic methods.

The choice of initial antihypertensive drug class should be based on an individualized patient assessment. One should consider whether the patient has simple hypertension or if their hypertension is complicated by the coexistence of other conditions (e.g., diabetes, coronary artery disease, heart failure, or prostatism) that may influence drug selection. Each of the antihypertensive drug classes have been shown to be effective in reducing blood pressure in the older patient population. For those with simple hypertension, the initial drug selection based on the evidence available to date is either a thiazide diuretic or a long-acting dihydropyridine calcium channel antagonist. Beyond this general recommendation, selection of a particular antihypertensive drug needs to be an individualized decision for each patient, taking into account the drug's potential advantages and disadvantages (see Table 40.2), together with the patient's comorbidities. Irrespective of the initial agent that is selected, in general, the starting dose should be reduced and dose titration done more gradually in an older hypertensive patient. If the target blood pressure goal is not obtained at a maximal dose of the initial agent following several months of treatment, therapy may either be switched to an alternate class or a second drug from another class may be added. A brief overview of the major classes of antihypertensive drugs that are currently recommended for initial therapy follows, focusing on their potential benefits and side effect profiles.

Diuretics

Therapy with low-dose thiazide diuretics (e.g., hydrochlorthiazide dose <50 mg daily, or equivalent) has demonstrated significant benefits in mortality, stroke, and coronary events in randomized clinical trials in older hypertensive patient populations. These beneficial effects combined with their relative safety, favorable side effect profile (their adverse metabolic effects—hypokalemia, hyperuricemia, and glucose intolerance—are attenuated at lower doses), once-daily dosing, and low cost have led to the recommendation that thiazide diuretics are preferred for initial therapy. Another advantage is that diuretic therapy leads to a disproportionate reduction in systolic relative to diastolic blood pressure and is better at achieving a reduction in systolic blood pressure compared to other agents.