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V Vertes

Publications and source records attributed to V Vertes.

14 recordsLinked to original sources

Comparative pharmacokinetics of captopril, enalapril, and quinapril.

This review compares the metabolism and pharmacokinetic profiles of captopril, the first orally active angiotensin-converting enzyme (ACE) inhibitor, and 2 newer ACE inhibitors, enalapril and quinapril. Captopril differs from both enalapril and quinapril in that its chemical structure contains a sulfhydryl group, the presence of which may be important in the development of adverse reactions. Captopril also differs from enalapril and quinapril in its ability to be metabolized in plasma. Enalapril and quinapril are both de-esterified, most likely in the liver, to their active metabolites, enalaprilat and quinaprilat. All 3 ACE inhibitors are eliminated primarily via renal excretion, and renal dysfunction markedly increases the area under the time versus plasma concentration curves. Hepatic dysfunction also slows the conversion of enalapril and quinapril to their active metabolites. There is evidence that both captopril and enalapril, but not quinapril, may accumulate with repeated dosing. The pharmacokinetics of these agents are not significantly modified by co-administration of other drugs. However, captopril does cause marked increases in trough plasma levels of digoxin. Overall, the pharmacokinetic profiles of captopril, enalapril, and quinapril make them suitable for a wide range of patients with hypertension or congestive heart failure.

Angiotensin-Converting Enzyme Inhibitors

Historical reflections on hypertension.

Sixty million Americans have hypertension, a major cardiovascular risk factor. Its presence accelerates the atherosclerotic process, producing strokes, heart attacks, heart failure, renal failure, and peripheral vascular disease. This article highlights the historical landmarks in the study of this disease from the first documented measurement of blood pressure in 1733, through the most recent pharmacologic approaches to treatment. In addition, the roles of the kidney and the renin-angiotensin-aldosterone system are examined.

Aldosterone

A comparison of the efficacy and safety of a beta-blocker, a calcium channel blocker, and a converting enzyme inhibitor in hypertensive blacks.

A double-blind, positively controlled, forced dose titration study comparing the efficacy and safety of atenolol, captopril, and verapamil sustained release as single agents in the treatment of black patients with mild to moderate hypertension (diastolic blood pressure, 95 to 114 mm Hg) was conducted. A total of 394 patients were randomized to one of the three therapies. Mean blood pressures during a 2- to 4-week placebo treatment period (baseline) ranged from 100.4 to 100.7 mm Hg diastolic and 151.7 to 152.5 mm Hg systolic for the three groups. Of the patients, 355 (of whom 345 had assessable data) completed the first treatment period, which consisted of therapy with either 50 mg/d of atenolol, 25 mg every 12 hours of captopril, or 240 mg/d of verapamil sustained release. During the second 4-week treatment period, which 319 patients completed (307 assessable), half of the patients had their antihypertensive medication increased and the other half continued the same dose. Goal blood pressure was defined as a supine diastolic pressure of less than 90 mm Hg or a 10-mm Hg or greater drop in supine diastolic blood pressure from pretreatment levels. Atenolol, captopril, and verapamil sustained release therapy was associated with goal blood pressure achievement during the first treatment period 55.1%, 43.8%, and 65.2% of the time, respectively, and during the second treatment period 59.6%, 57.1%, and 73.0% of the time. Side effects were minimal and comparable for all three drugs.

Adult

Ticrynafen and hydrochlorothiazide. A double-blind study of antihypertensive properties with an open crossover.

Twenty-eight patients completed a double-blind study of the antihypertensive effects of ticrynafen compared with those of hydrochlorothiazide. The results of blood pressure reduction were comparable in the two groups. After six months, 12 patients were crossed over to ticrynafen therapy from hydrochlorothiazide. They maintained their blood pressure reduction. The most striking difference between the two groups was in the uric acid response. The uric acid level in the patients receiving hydrochlorothiazide therapy rose from a baseline of 5.9 to 7.5 mg/dL (normal range, 3.0 to 8.0 mg/dL). The uric acid level of those patients receiving ticrynafen therapy decreased from a baseline of 6.4 mg/dL to a low of 3.3 mg/dL. In view of ticrynafen's appreciable antihypertensive and uric-acid-lowering effects, it appears to be a useful new antihypertensive drug.

Adult

The preoperative patient wit hypertension.

Preoperative medical evaluation of the hypertensive patient has a dual focus: (1) to establish an appropriate level of blood pressure control before anesthesia and surgery; and (2) to assess the degree of cardiovascular impairment, with particular attention to brain, heart, and kidney. Close communication between clinician and anesthesiologist can do much to ensure the patient's safety. Interpretation of the results of the preoperative examination is aided by the clinician's prior knowledge of the patient: the onset and history of his hypertension, his record of compliance to an antihypertensive regimen, his blood pressure response during previous hospitalizations and surgical procedures. Though there is no longer any question that antihypertensive medications should be continued in the preoperative period, side-effects of thiazide therapy may need treatment before or during surgery. Again, the clinician's fuller knowledge of the patient will help to alert the anesthesiologist to the need for special caution.

Anesthesia

The massively obese hypertensive patient: an analysis of blood pressure response to weight reduction with supplemented fasting.

A 42.4% incidence of hypertension was seen in 783 massively obese patients admitted to a supplemented fasting program between February 1974 and November 1976. Chosen for this study were the 99 hypertensives who had not received any antihypertensive medication before admission. The blood pressure response after 1 week of inhospital fasting was compared with that at the end of a period of outpatient fasting. Reduction in blood pressure was noted in 85 patients by the end of the first week; by the end of the fasting period, 68 patients were normotensive. We conclude that the elevated blood pressure common in a high percentage of massively obese patients is primarily volume-dependent.

Blood Pressure

Supplemented fasting as a large-scale outpatient program.

Although supplemented fasting is now established as an efficient means of achieving substantial weight reduction in massively obese persons, widespread application of this treatment is contingent on its successful adaptation to a large-scale outpatient regimen. Of 519 patients treated as outpatients, 78% lost a minimum of 18.2 kg during the course of treatment. The overall rate of weight loss was 1.5 kg/wk, with females averaging 1.3 kg/wk and males, 2.1 kg/wk. The majority of patients tolerated the regimen well and were able to continue normal daily activities without experiencing any serious side effects.

Body Weight

The pathophysiology of renovascular hypertension.

Renovascular hypertension, comprising a small percentage of the total hypertensive population, stands out as remarkably important, being the most common cause of surgically correctable hypertension. Its precise diagnosis can be accomplished by judicious application of recently available sophisticated laboratory methods and correct prediction of curability is now possible. Careful selection of cases among the vast numbers of hypertensives by routine screening procedures is essential. The selected few deserve more complete studies including bilateral renal vein renin measurements. Rapid sequence pyelography, split function studies, radioisotope renorgram, and renal arteriography accurately define the presence of a significant structural abnormality involving the renal circulation on either side. Significant bilateral renal vein plasma renin differential, done under appropriate conditions of volume depletion and upright posture, in the absence of interference by concurrent antihypertensive drug therapy, establishes a causal relationship between the structural abnormality and the high blood pressure. A thorough knowledge of the normal physiology of the renin-angiotensin-aldosterone system and its inappropriate response in renovascular hypertension and other related clinical conditions is clearly necessary if one is to plan diagnostic studies intelligently and interpret the results correctly.

Aldosterone

A comparison of the efficacy and tolerability of enalapril and sustained-release diltiazem in mild to moderate essential hypertension.

The subjects of this multicenter study were 159 patients aged 21 to 76 years with mild to moderate uncomplicated essential hypertension. The patients were randomly assigned to receive up to 40 mg of enalapril daily or 360 mg of sustained-release diltiazem daily for a titration period of eight weeks and then maintenance doses for four weeks. The treatment goal was a supine diastolic blood pressure of less than 90 mmHg or a fall of at least 10 mmHg from baseline. During titration, 62% of the enalapril-treated patients and 51% of the diltiazem-treated patients reached the treatment goal after two weeks, 82% and 74% after four weeks, 87% and 84% after six weeks, and 92% and 87% after eight weeks. During the maintenance period, 85% of the enalapril-treated and 87% of the diltiazem-treated patients maintained the goal blood pressure. Treatment side effects were reported by 21% of the enalapril-treated patients and 29% of the diltiazem-treated patients; treatment was discontinued in two patients from each group because of side effects. It is concluded that both drugs were generally well tolerated and effective in the treatment of adult mild to moderate essential hypertension.

Adult