Sympathetic Nervous Function and Renin Activity in Hypertensives on Long Term Drug Treatment with Propranolol, Methyldopa or Bendrofluazide

Abstract

Plasma noradrenaline and plasma renin activity were measured as indices of sympathetic activity and renin angiotensin system in similar groups of hypertensive patients receiving either propranolol, bendrofluazide or methyldopa. Plasma renin activity was similar in the propranolol and methyldopa groups and significantly lower (p less than 0.01) in both these groups than the diuretic treated subjects. Plasma noradrenaline was significantly lower (p less than 0.01) on methyldopa than either propranolol or bendrofluazide. These different effects on the renin angiotensin system and the sympathetic nervous system of these drugs may be relevant in the choice of long term therapy in hypertension.

Plasma noradrenaline concentration in essential hypertension during long‐term beta‐adrenoceptor blockade with oxprenolol.

“…A study by Polak, Reid, Hamilton, Jones & Dollery (1978) in three groups of hypertensive patients treated with a single drug regime consisting of either a thiazide diuretic, propranolol or methyldopa, showed that the mean plasma noradrenaline level for the methyldopa treated group was significantly lower than that for the other groups, which would be consistent with the view that methytdopa has an important central nervous site of action. However, as there were no control data before treatment available in this study, it was difficult to interpret the plasma noradrenaline in the fl-adrenoceptor blocker treated group.…”

Mechanism of the Antihypertensive Action of <i>&beta;</i>-Adrenergic Blocking Drugs

“…Similar results or even a rise in noradrenaline have been obtained with propranolol (Franco-Morselli et al, 1978), atenolol (Distler et al, 1978, metoprolol (Hansson et al, 1977;Lijnen et al, 1979). Additional evidence for the lack of importance of a central action of blocking drugs comes from the observation that the serum noradrenaline levels in patients treated with methyldopa was significantly lower than those treated with pro pranolol, which were similar to those receiving bendrofluazide (Polak et al, 1978).…”

Propranolol and beta‐adrenergic receptor blocking drugs in the treatment of hypertension.

“…Changes of plasma noradrenaline in response to various sympathetic activities, sleeping, supine, awake, standing, walking and cycling are not reduced by j8-adrenoceptor blockade (Watson et al, 1980). Further evidence of the lack of importance of a central hypotensive action of ,8-adrenergic receptor blocking drugs comes from the observations that the serum noradrenaline levels in patients treated with methyldopa were significantly lower than in those treated with propranolol, which were similar to those in patients receiving bendrofluazide (Polak et al, 1978).…”