[Doxazosin for the treatment of arterial hypertension]. / La doxazosina nel trattamento dell'ipertensione arteriosa.

Hypertension is often associated to other risk factors, such as abnormal lipid and carbohydrate metabolism, which should be considered for the choice of antihypertensive drug treatment. Doxazosin is a postsynaptic alpha-1 adrenoceptor blocker suitable for once a day treatment regime. It seems to induce fewer side effects than older drugs of the same class and it may improve lipid and carbohydrate profile, thereby reducing the risk of coronary artery disease. To verify its effects on blood pressure, serum lipids and glucose tolerance, doxazosin (1-8 mg od) was given for 8 weeks to 32 patients suffering from essential hypertension, of whom 16 had fasting serum cholesterol higher than 6 mmol/l and/or fasting serum triglycerides higher than 1.9 mmol/l. Sitting and standing blood pressure were significantly reduced (from 163 +/- 18/101 +/- 6 mmHg to 147 +/- 19/94 +/- 8, p less than 0.001 and from 162 +/- 18/107 +/- 9 to 145 +/- 18/95 +/- 8, p less than 0.001, respectively) at a mean daily dose of 5 mg. Normotension or a good hypotensive response was achieved in 60% of the patients. The daily dose which turned out to be effective in 50% of the patients was 7 mg. The drug treatment was well tolerated and orthostatic hypotension was never observed either on starting treatment or on increasing dosage. Blood lipids and glucose tolerance were not significantly affected. Doxazosin is therefore an effective antihypertensive agent suitable for use in patients with essential hypertension alone or combined with hyperlipidemia.

Plethysmographic effects of doxazosin in essential hypertensive patients.

In the treatment of hypertensive patients with peripheral vascular disease, alpha 1-adrenoceptor blockers may be considered first-choice drugs since they reduce the total peripheral resistance and do not decrease the plasma volume. As a preliminary step, we investigated the plethysmographic effects of doxazosin (1-8 mg for 6 weeks) on calf flow in 32 uncomplicated hypertensive patients. Despite the fall in sitting and standing blood pressure (from 163 +/- 18/101 +/- 6 to 147 +/- 19/94 +/- 8 mmHg and from 162 +/- 18/107 +/- 9 to 145 +/- 18/95 +/- 8 mmHg, respectively; both P less than 0.001) the calf flow was not decreased at rest and after ischaemia. Resting resistance was not significantly reduced (from 49.5 +/- 35 to 38.9 +/- 33 mmHg/100 ml per min) but its fall was significantly correlated with the fall in mean blood pressure (rs = 0.35, P less than 0.05). These findings confirm that doxazosin may be useful in the treatment of hypertension complicated by peripheral artery disease.

Red blood cell Na+/H+ and Li+/Na+ exchange in patients with essential hypertension.

The increased red blood cell Li+/Na+ exchange found in a subgroup of patients with essential hypertension (EH) may reflect an increased activity of the Na+/H+ exchange. The maximal velocity of the red cells' Na+/H+ (Na+ influx promoted by an outward H+ gradient) and Li+/Na+ (Li+ efflux promoted by external Na+) exchange were therefore measured in 41 EH and in 21 normotensive controls (NT). Both transporters were significantly higher in EH than in NT (74 +/- 39 mmol/L cell x h v 43 +/- 27 for the former, P less than .03, and 0.35 +/- 0.16 v 0.26 +/- 0.10 for the latter, P less than .05). Even though more than 100 times faster, Na+/H+ exchange was weakly but significantly correlated to Li+/Na+ exchange (r = 0.29, P less than .05). Proximal tubule Na+ reabsorption (fractional renal Li+ reabsorption) was significantly greater in EH than in NT (0.78 +/- 0.07, n = 32, v 0.73 +/- 0.06, n = 10, P less than .05) but it was not correlated to either the red cells' Na+/H+ or Li+/Na+ exchanges. Therefore, hyperactivity of Na+/H+ exchange in EH may play a role in blood pressure elevation through mechanisms other than stimulation of renal Na+ reabsorption.

[Volume of the extracellular liquid and renal function during short-term administration of angiotensin converting enzyme inhibitors in essential hypertension]. / Volume dei liquidi extracellulari e funzione renale in corso di somministrazione a breve termine di ACE-inibitori nell'iperteso essenziale.

Short term angiotensin converting enzyme inhibition may induce a transient salt and water retention in patients with hypertension or heart failure. To verify the glomerular and tubular effects of short term converting enzyme inhibition, thirteen patients with mild to moderate essential hypertension (WHO I-II) were treated orally either with perindopril (4 mg o.d.) or captopril (25 mg b.i.d.) for one week. Both drugs reduced supine mean blood pressure significantly (p less than 0.01) (perindopril from 126 +/- 11 to 108 +/- 7 mmHg, mean +/- SD, and captopril from 132 +/- 12 to 121 +/- 16). Plasma volume (radio-iodinated albumin space) was unchanged while mean extracellular fluid volume (inulin space) increased although not significantly (from 5.05 +/- 1.32 l/sqm to 5.71 +/- 2.21 with perindopril and from 4.96 +/- 2.6 to 5.6 +/- 1.7 with captopril). Sodium clearance decreased (from 1.4 +/- 0.6 to 1.1 +/- 0.5 ml/min 1.73 sqm with perindopril, p less than 0.05, and from 0.97 +/- 0.44 to 0.88 +/- 0.51 with captopril, n.s.). In 9 patients (6 on captopril and 3 on perindopril) extra-cellular fluid volume increased simultaneously with reduction in glomerular filtration rate and in proximal tubule sodium re-absorption as well as an increase in distal tubule sodium reabsorption. In these patients the changes in proximal and distal tubule sodium reabsorption were significantly (p = 0.05) different from those of the patients with no extra-cellular fluid expansion.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal renal angioplasty: influence of complications on long-term blood pressure results.

Natural history and outcome of percutaneous transluminal renal angioplasty (PTRA) in renovascular hypertension (RVH) were assessed retrospectively in 52 patients in whom 62 PTRAs were successfully performed. Complications were observed in 16 patients: prolonged and extensive arterial spasms in eight, severe intimal dissection of the main renal artery in five, arterial thrombosis at the site of PTRA in two and acute deterioration of renal function in one. All the complications cleared up with medical treatment except for one major dissection occluding the distal branches, which required surgery. According to the Co-operative Study, after 1-5 years of follow-up, 21 patients (40.4%) were cured, 27 (51.9%) improved and four (7.7%) did not improve. The long-term results on blood pressure in both uncomplicated and complicated cases were better in fibrodysplasia (61.5% cured, 34.6% improved and 3.8% not improved) than in atherosclerosis (17.4% cured, 69.6% improved and 13% not improved). In the last 21 PTRAs performed, in which verapamil (200-1500 micrograms) was given as a bolus injection into the stenotic artery before dilatation, the complication rate was significantly lower. It is concluded that PTRA is an effective treatment for RVH; complications occurred in 25.8% of PTRAs and resulted in poor control of blood pressure in atherosclerosis but not in fibrodysplasia; premedication with verapamil into the stenotic renal artery reduced the complication rate.