Hemodynamic changes in long-term -methyldopa therapy of essential hypertension

Evaluation and treatment of hypertension in active individuals

Hypertension is a very common vascular disease. It is seen in adolescents, obese persons, postmenopausal women, and the elderly. A nonpharmacologic approach to treatment is a critical first step in management. The modalities include a diet low in salt and saturated fat, exercise, less than 2 ounces of alcohol daily, and abstinence from smoking. Dynamic (aerobic) exercise is effective in lowering blood pressure (BP) only if performed regularly. Weight reduction by diet must be combined with exercise if there is to be a reduction in BP. Strength training is not to be considered as an alternative to aerobic training for reducing BP. Antihypertensive mediation can be added to nonpharmacologic interventions for additional BP reduction. Beta-blockade is not a contraindication to exercise training.

The hypertensive patient with concomitant cardiovascular disease

Many drugs for the treatment of hypertension are available in the United States today. Of the various factors that determine the appropriate treatment for a particular patient, the presence of concomitant heart disease requires specific tailoring of the antihypertensive therapy. Coronary artery disease, aortic insufficiency, congestive heart failure, left ventricular hypertrophy, premature ventricular contractions, supraventricular arrhythmias, mitral valve prolapse, orthostatic hypotension, and aortic dissection are some of the conditions that influence the choice of treatment. Diabetes places hypertensive patients at increased risk of heart disease, and exercise and sexual function are other considerations that govern the selection of treatment for the hypertensive person. For all of these conditions, more than one drug choice is often possible, but usually hypertensive patients can be treated with a beta-blocker or a calcium channel blocker in these special circumstances.

Antiadrenergic therapy: special aspects in hypertension in the elderly

The effect of antiadrenergic treatment with methyldopa was studied in 17 patients with established essential hypertension who were subdivided with respect to age in a group younger (n = 10; mean age, 47 +/- 2.4 (SEM) years; and a group older than 60 years of age (n = 7, mean age, 67 +/- 2.8 SEM). The fall in arterial pressure was associated with a significant (p less than 0.05) decrease in cardiac output and heart rate in patients over 60 years of age and no change in total peripheral resistance, whereas a (nonsignificant) fall in resistance occurred in younger patients. In both age groups, a significant (p less than 0.05 and less than 0.01, respectively) decrease in plasma norepinephrine levels was observed, whereas epinephrine and dopamine showed no changes. Pre- and posttreatment values of mean arterial pressure correlated directly with plasma norepinephrine values (r = 0.35 p less than 0.05). Regardless of whether cardiac output was reduced or remained unchanged, renal blood flow, plasma and total blood volume did not change in either group with antiadrenergic treatment. Further, reflexive cardiac changes (responses to isometric exercise and upright tilt) remained qualitatively unchanged. It is concluded that antiadrenergic treatment with methyldopa lowers arterial pressure additionally by decreasing circulating norepinephrine levels. The antihypertensive effect is associated with a fall in peripheral resistance in the younger and a decrease in cardiac output in the older patients, and does not compromise renal blood flow or cardiac reflexive responses.

Changes in plasma and extracellular fluid volume during long-term treatment with alpha-methyldopa in 11 thiazide-treated patients with essential hypertension

In eleven patients with essential hypertension, plasma volume (T-1824) (PV), extracellular fluid volume (82Br-distribution space) (ECFV), blood pressure (BP) and the ratio plasma to interstitial fluid volume (PV/IF) have been determined three times before treatment, after more than two months of thiazide treatment and after three and six months of combined thiazide-alpha-methyldopa (AMD) therapy. During combined treatment, PV/IF showed a significant increase, whereas PV and ECFV did not change significantly. Compared to values during thiazide therapy, PV and PV/IF increased, whereas ECFV was unchanged. BP was reduced significantly after thiazide treatment and showed a further significant fall when AMD was added. Based on the results and a review of the literature, it is concluded that AMD acts by interfering with the normal sympathetic activity, thereby producing a reduced venomotor tone and increased venous capacity. The concomitant reduced venous return of blood to the heart is suggested to contribute to the antihypertensive effect of AMD by means of a decreased cardiac output.