Initial antihypertensive therapy. Comparison of prazosin and hydrochlorothiazide

Association of Thiazide-Type Diuretics With Glycemic Changes in Hypertensive Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials

Patients receiving thiazide diuretics have a higher risk of impaired glucose tolerance or even incident diabetes, but the change of blood glucose level varies across different trials. The aim of this study was to investigate the glycemic changes in hypertensive patients with thiazide-type diuretics. Twenty-six randomized trials involving 16,162 participants were included. Thiazide-type diuretics were found to increase fasting plasma glucose (FPG) compared with nonthiazide agents or placebo or nontreatment (mean difference [MD], 0.27 mmol/L [4.86 mg/dL]; 95% confidence interval [CI], 0.15-0.39). Patients receiving lower doses of thiazides (hydrochlorothiazide or chlorthalidone ≤25 mg daily) had less change in FPG (MD, 0.15 mmol/L [2.7 mg/dL]; 95% CI, 0.03-0.27) than those receiving higher doses (MD, 0.60 mmol/L [10.8 mg/dL]; 95% CI, 0.39-0.82), revealed by the subgroup analysis of thiazides vs calcium channel blockers. Thiazide-type diuretics are associated with significant but small adverse glycemic effects in hypertensive patients. Treatment with a lower dose might reduce or avoid glycemic changes.

A relationship between blood pressure control, hematocrit level, and renal function in treated essential hypertension

The effect of rigid blood pressure control on renal function is an unsettled issue. This study describes a retrospective analysis on the relationships between blood pressure control, hematocrit levels, and renal function in 97 treated hypertensive patients. Data analysis was done on systolic and diastolic blood pressure, hematocrit levels, renal function assessed by serum urea nitrogen (SUN), serum creatinine (Scr), and hydrochlorothiazide (HCTZ) dose at entry and at four anniversary dates thereafter. The patients were divided into two groups: group I and group II on the basis of HCTZ dose. Group I received an average of 100 mg HCTZ daily, whereas group II received an average of 50 mg HCTZ daily. In group I, the decrement in both systolic and diastolic blood pressure over time was highly significant (P < .0001); however, no change in renal function was noted. In group II, systolic blood pressure decreased significantly (P < .01) from entry to year 1, then leveled off. In year 4, systolic blood pressure was not different from that of entry. Conversely, the difference between entry and year 4 diastolic blood pressure was highly significant (P < .0001). In group II, significant decreases were noted between entry and year 4, SUN (16.5 +/- 5.7 versus 14.9 +/- 4.1 mg/dL; P < .0012) and Scr (1.29 +/- .23 versus 1.24 +/- .19 mg/dL; P < .0192). Hematocrit showed diverse responses; in group I, hematocrit significantly increased from entry to year 4 (44.8 +/- 2.5 versus 47.2 +/- 3.9%; P < .01); whereas, in group II, hematocrit significantly decreased (47.7 +/- 3.8 versus 44.9 +/- 3.4%; P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin resistance and hypertension

The author has reviewed the development of the concept that insulin resistance is related not only to the hypertensive state but potentially to the initiation and maintenance of high blood pressure. Potential sequelae of insulin resistance and hyperinsulinemia, as they apply to atherogenesis, are also discussed. The impact of present antihypertensive pharmacologic therapy on insulin resistance is addressed, as are future directions in pharmacologic and nonpharmacologic management of hypertension. In addition, the author speculates on possible mechanisms leading to insulin resistance in hypertension.

Drug-related syncope

The records of 483 patients admitted to the emergency room because of syncope were reviewed. Forty-one patients were found to have drug-related syncope. Thirty-nine experienced syncope related to drugs administered for cardiovascular disease. The most frequently associated diseases were anginal syndrome (22 patients), hypertension (13 patients), and a history of myocardial infarction (6 patients). Thirty-eight patients experienced symptomatic orthostatic hypotension following drug taking (nitrates in 19 patients, beta blockers in 10 patients, nifedipine in 3 patients, prazosin and quinidine in 2 patients each, methyldopa and verapamil in 1 patient each). One patient developed complete heart block as a result of digoxin intoxication. Two patients developed the characteristic picture of anaphylactic reaction (1 with ampicillin, 1 with dipyrone). During one-year follow-up, without the offending medications, no further syncopal episodes were reported by these patients. We conclude that drug-related syncope was more common among our patients with syncope than had been reported previously. It is suggested that drug-related syncope should be taken into consideration in any patient with syncope who is treated by any of the above-mentioned drugs.

Evaluation of the efficacy of prazosin versus propranolol as initial antihypertensive therapy

The long-term effects of prazosin and propranolol therapy were compared over the course of one year in 93 patients with mild-to-moderate hypertension. Thirty-four of the 44 patients randomly assigned to receive prazosin therapy and 38 of the 49 patients assigned to propranolol therapy received monotherapy for one year, whereas the remaining patients received concomitant hydrochlorothiazide therapy. Blood pressure was significantly decreased (p less than 0.01) in all treatment groups throughout the study compared with baseline measurements. The blood pressure responses to treatment were not shown to differ among patients with low, normal, or high renin levels on entry. No significant differences from baseline were noted among treatment groups with regard to lipid profiles. In summary, prazosin and propranolol were shown to have comparable long-term blood pressure-lowering effects when given as monotherapy in patients with mild-to-moderate hypertension.

Thiazide diuretics and selective alpha blockers: comparison of use in antihypertensive therapy, including possible differences in coronary heart disease risk reduction

The results of several important clinical trials have confirmed the benefits of pharmacologic treatment in patients with hypertension. However, some issues concerning this type of treatment have yet to be resolved. For example, it has not been determined whether there are differences among antihypertensive agents with respect to their effects on mortality and morbidity or whether such effects are independent of the alterations in blood pressure resulting from the use of such agents. Thiazide diuretics, the most commonly prescribed antihypertensive drugs, were the first agents proven to be effective and practical for the widespread treatment of hypertension. Alpha blockers, also commonly prescribed antihypertensive drugs, provide equally effective blood pressure control to that of the thiazides, but with a very different metabolic profile. In this article, these drugs are compared for efficacy, side-effect profiles, metabolic effects, and potential for reducing the risk of coronary heart disease.