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Biomedical subjects

L M Prisant

Publications and source records attributed to L M Prisant.

At least 37 records · Page 2Linked to original sources
PubMed1998

Low-dose combination treatment for hypertension versus single-drug treatment-bisoprolol/hydrochlorothiazide versus amlodipine, enalapril, and placebo: combined analysis of comparative studies.

To assess the efficacy and safety of 2.5, 5, and 10 mg bisoprolol/6. 25 mg hydrochlorothiazide (HCTZ), 2.5, 5, and 10 mg amlodipine; and 5, 10, 20, and 40 mg enalapril in subjects (n = 541) with a sitting diastolic blood pressure of 95 to 114 mm Hg, data from two comparative studies were pooled. All drugs were titrated to a diastolic blood pressure 90 mm Hg or less. Both studies were double-blind, randomized, parallel dose escalation trials with similar designs and included three active treatments. The second study also had a placebo group. The mean change from baseline of systolic and diastolic blood pressure for placebo (n = 79) was -0. 1/-2.2 mm Hg; amlodipine (n = 154), -12.4/-10.3 mm Hg; enalapril (n = 155), -9.4/-8.2 mm Hg; and bisoprolol/HCTZ (n = 155), -14.0/-12.0. Overall efficacy analyses documented a statistically significant decrease in sitting diastolic blood pressure for bisoprolol/6.25 mg HCTZ compared with placebo, amlodipine, and enalapril. There was a significant reduction in sitting systolic blood pressure for bisoprolol/6.25 mg HCTZ compared with placebo and enalapril but not amlodipine. Also, there was a significant decrease in sitting heart rate for bisoprolol/6.25 mg HCTZ (-6.2 beats/min) compared with placebo (+0.1 beats/min), amlodipine (+1.2 beats/min), and enalapril (+0.5 beats/min). The control rate (diastolic blood pressure < or = 90 mm Hg) for bisoprolol/6.25 mg HCTZ (66.5%) was significantly better than for placebo (21.8%) and enalapril (47.1%) but not amlodipine (58.4%). Of those patients achieving and maintaining control, 49% of the bisoprolol/6.25 mg HCTZ subjects were on the lowest two doses compared with 30% of the amlodipine and 26% of the enalapril subjects. Percentages of patients reporting at least one drug-related adverse event through week 12 were 27%, 24%, 28%, and 25% for placebo, bisoprolol/6.25 mg HCTZ, amlodipine, and enalapril (not significant). Lower doses of two drugs in fixed combination can provide as good or better blood pressure control compared with higher doses of a single drug with similar tolerability and safety.

Amlodipine↗
PubMed1998

Calcium antagonists--pharmacologic considerations.

Calcium antagonists work by blocking the entrance of calcium from the outside of the cell to the inside of the cell through the voltage-dependent calcium channels. There are three major L-type (high voltage) calcium channel blocker sites (a dihydropyridine site for nifedipine, a phenylalkylamine for verapamil, and a benzothiazepine site for diltiazem) and a tetralol T-type (low voltage) calcium antagonist. Calcium antagonists differ in terms of their tissue affinity and vascular selectivity resulting in different therapeutic applications. The initial disadvantage of a short-half has been overcome with drug delivery systems that lower blood pressure over a twenty-four hour period. These calcium antagonists are effective in lowering blood pressure and reducing anginal episodes in African Americans and whites, regardless of age or renin level.

Angina, Unstable↗
PubMed1998

Calcium antagonists--clinical considerations.

Calcium antagonists are useful for treating hypertension, stable exertional and vasospastic angina, and supraventricular arrhythmias. Recent studies have proven their ability to decrease the rate of nonfatal strokes. Short-acting calcium antagonists should be avoided with hypertensive emergencies and urgencies, unstable angina, and acute myocardial infarction. The use of calcium antagonists in systolic heart failure should not be as the primary therapy. Care must be taken in using non-dihydropyridines because of multiple drug-drug interactions. Prospective trials are in progress through the next decade that will compare traditional drugs such as diuretics and beta-blockers to calcium antagonists, converting enzyme inhibitors, and angiotensin II receptor blockers.

Administration, Sublingual↗
PubMed1997

Metyrosine and pheochromocytoma.

BACKGROUND: Severe hemodynamic instability may occur during surgery for removal of pheochromocytoma, unless there is preoperative pharmacological treatment. OBJECTIVE: To evaluate the effects of metyrosine (alpha-methyl-p-tyrosine), a catecholamine synthesis inhibitor, and alpha-blockade with prazosin or phenoxybenzamine on cardiovascular morbidity during surgery for pheochromocytoma. METHODS: A retrospective analysis was made of patients followed up at the Medical College of Georgia, Augusta, during 28 years who received metyrosine and prazosin (n = 6), metyrosine and phenoxybenzamine alone (n = 14), phenoxybenzamine alone (n = 6), or no medication (n = 7) during 3 weeks before tumor removal. The percentage of patients not requiring pressors or phentolamine during the intraoperative period as well as the perioperative peak systolic pressures and peak heart rates were estimated in each group. RESULTS: There was a significant (P < .05) increase in intraoperative peak systolic pressures without preoperative treatment (mean +/- SD, 243 +/- 40 mm Hg) vs metyrosine (mean +/- SD, 168 +/- 27 mm Hg). Ninety-five percent of patients who received metyrosine did not require pressors intraoperatively vs 50% with phenoxybenzamine alone. Eighty-one percent of patients pretreated with metyrosine did not require intraoperative phentolamine vs 33% with phenoxybenzamine alone and 29% without medications. Two patients in the no medication group died as a results of hypertensive crisis. CONCLUSIONS: The combination of alpha-metyrosine and alpha-blockade results in better blood pressure control and less need for use of antihypertensive medication or pressors during surgery, compared with the classical method of single-agent adrenergic blockade. Preoperative treatment with metyrosine along with an alpha-blocker is a useful strategy for decreasing the surgical morbidity in patients with pheochromocytoma and assumes greater importance as long as the availability of phentolamine for intraoperative use is a problem.

Adolescent↗
PubMed1997

Beta-blocker use in systolic heart failure and dilated cardiomyopathy.

Statistics regarding long-term survival for patients with heart failure are discouraging today. Converting enzyme inhibitors have produced a modest effect on mortality. beta-Blockers may be the next addition to standard therapy for heart failure because they generate consistent improvements in hemodynamic factors, symptom scores, and submaximal exercise tolerance in randomized, controlled clinical trials. They augment ejection fraction, reduce heart volume, and consistently lower neurohormonal activation as reflected by plasma norepinephrine levels. Trials with carvedilol and bisoprolol suggest an effect on mortality similar to that with converting enzyme inhibitor trials. Future studies, especially the beta-blocker Evaluation Survival Trial (BEST), with mortality as the main end point should elucidate the degree of effect on mortality further.

Adrenergic beta-Antagonists↗
PubMed1997

Hypertension: the rediscovery of combination therapy.

Awareness and treatment of hypertension in the United States has been improving for older patients, but hypertension continues in many cases to be poorly controlled. Three options exist if initial therapy fails to achieve target blood pressure: upward drug titration, substituting another drug, or combination drug therapy. Combination therapy is the attempt to optimize blood pressure control by using two or more agents with additive or synergistic effects. Problems with this approach include noncompliance due to complicated regimens, adverse drug reactions, and the added expense of multiple medications. However, the newer fixed-dose combination products have been shown to offer improved blood pressure control, simplification of drug regimens, decreased adverse reactions, improved compliance, and cost-effectiveness.

Aged↗
PubMed1996

Efficacy and tolerability of lovastatin in 459 African-Americans with hypercholesterolemia.

A paucity of substantive data from clinical drug trials is available specifically evaluating the effects of therapy for hypercholesterolemia in African-Americans, even though a substantial number are candidates for medical advice and intervention for high blood cholesterol. The efficacy and safety of lovastatin in 459 African-Americans with hypercholesterolemia were studied in the Expanded Clinical Evaluation of Lovastatin study, a multicenter, double-blind, diet- and placebo-controlled trial. This trial involved 8,245 patients who were randomly assigned, regardless of race, to receive placebo or lovastatin at doses of 20 mg once daily, 40 mg once daily, 20 mg twice daily, or 40 mg twice daily for 48 weeks. Among African-Americans, lovastatin produced sustained, dose-related (p <0.001) decreases in low-density lipoprotein cholesterol (20% to 38%), total cholesterol (14% to 28%), and triglycerides (8% to 15%). From 75% to 96% of African-Americans treated with lovastatin achieved the National Cholesterol Education Program goal of low-density lipoprotien cholesterol <160 mg/di, and from 33% to 71% achieved the goal <130 mg/di. The safety profile of lovastotin in African-Americans was generally favorable. A relatively high incidence of creatine kinase levels greater than the upper limit of normal was observed in African-Americans during the study, i.e., 63% in the placebo group and similar levels in lovastatin treatment groups. Lovastatin is highly effective and generally well tolerated as therapy for primary hypercholesterolemia in African-Americans.

Black or African American↗
PubMed1996

Losartan: first of a new class of angiotensin antagonists for the management of hypertension.

Angiotensin receptor antagonists represent a new class of drugs for the treatment of patients with hypertension. Reduction of blood pressure in patients with essential hypertension requires increased activity of the renin-angiotensin system. Losartan, the first orally active, nonpeptide angiotensin antagonist, specifically competes with angiotensin II (Ang II) for the AT1 receptor and reversibly alters the receptor. Maximum blood pressure reductions occur after doses of approximately 50 mg, although some patients will require 100 mg; the parent compound and a metabolite are responsible for a smooth 24-hour effect on blood pressure. Once-daily dosing with losartan has been documented to be safe. The drug's safety has been evaluated in 4,058 patients; of these patients, more than 1,200 were treated for longer than 6 months and more than 800 were treated for longer than 1 year with doses of 10 mg to 150 mg. Overall, no hypertensive patients were withdrawn from treatment because of elevated serum creatinine or potassium levels, and there were no reports of angioedema. In addition, some reductions in plasma uric acid levels were noted. Cough occurred significantly less often in patients treated with losartan than in those treated with hydrochlorothiazide or lisinopril. In contrast to angiotensin-converting enzyme (ACE) inhibitors, losartan does not activate bradykinin-nitric oxide-prostanoid vasodilation.

Angiotensin Receptor Antagonists↗
PubMed1996

Use of beta-adrenergic receptor blockers in blacks.

Beta adrenergic receptor blockers (beta-blockers) are an important class of drugs in the management of patients with cardiovascular diseases. These drugs have been shown to reduce mortality in hypertension and prolong survival in patients with coronary heart disease. Although hypertension and coronary heart disease account for the majority of excess cardiovascular morbidity and mortality in blocks, beta-blockers continue to be underprescribed in this ethnic group. The magnitude of blood pressure reduction in black patients with hypertension has been consistently less during monotherapy with nonselective beta-blockers than with diuretics. However, the highly selective beta-blocker bisoprolol has been shown to be as effective as diuretics and is equally effective in black and nonblack patients with hypertension. In general, no racial differences in efficacy are noted when beta-blockers are used with diuretics as combination therapy for hypertension. Black patients should not be denied beta-blocker therapy because of an anticipated suboptimal response, especially when there are clear indications for treatment (e.g., for migraine, hyperthyroidism, arrhythmia control, and after myocardial infarction).

Adrenergic beta-Antagonists↗
PubMed1996

Antihypertensive therapy and quality of life. Influence of blood pressure reduction, adverse events, and prior antihypertensive therapy.

Quality of life is an important attribute of antihypertensive therapy. Previous studies have not addressed the importance of a patient's prior pharmacotherapy on quality of life, which may serve as the basis of reference for a new therapy. Nor have previous studies compared commonly used quality of life instruments for consistency, or investigated whether improvement or worsening of quality of life correlates with adverse events or blood pressure reduction. Two hundred eighteen hypertensive patients with diastolic blood pressure (95 to 114 mm Hg) after a 4- to 5-week placebo washout period were enrolled in a randomized double-blind, parallel group dose-escalation trial to compare the effects of amlodipine (2.5 to 10 mg), bisoprolol (2.5 to 10 mg)/hydrochlorothiazide (HCTZ) 6.25, and enalapril (5 to 20 mg) on blood pressure, adverse events, and quality of life. Three quality of life instruments (General Well-Being Index, Vital Signs Quality of Life, Zung Self-Rating Depression Scale) were administered during original therapy, after placebo washout, and after 12 weeks of optimally titrated clinical trial pharmacotherapy. Our results demonstrated that removal from prior therapy had no detectable influence on subsequent evaluation of quality of life. The three quality of life instruments were consistent with the changes observed with the three therapies: a trend toward better quality of life with amlodipine and bisoprolol/HCTZ. Adverse events, but not systolic or diastolic blood pressure reduction correlated directly with changes in quality of life.

Adrenergic beta-Antagonists↗
PubMed1996

Ambulatory blood pressure monitoring: methodologic issues.

Blood pressure, like heart rate, is a changing physiologic variable. Like ambulatory electrocardiography, ambulatory blood pressure can be recorded intermittently throughout the day. Ambulatory blood pressure is a dynamic variable influenced by multiple factors, and it correlates more strongly with target organ damage than do static office blood pressure measurements. Office (but not ambulatory) measurements are subject to the placebo and physician pressor effect. There is a great patient variability of blood pressure measurements in the office compared with ambulatory methods. Ambulatory blood pressure devices are portable rather than 'ambulatory'. The auscultatory (listens for Korotkoff sounds) and oscillometric (detects maximal arterial vibrations and calculates diastolic blood pressure) methods are used to detect blood pressure. Equipment is generally safe, although mild sleep derangements have been reported. The 24-h blood pressure and diurnal change are usually assessed. A 24-h ambulatory blood pressure mean of 140/90 mm Hg or above is clearly abnormal, though recent data suggest that the 95th centile is 134/84 mm Hg. Correlation of individual blood pressure readings with diary entries may be instructive. New American and British validation criteria have been published to assess the performance of each new device that becomes available. It should not be assumed that newer ambulatory devices have been tested (particularly by a third party) or are better. Test/retest 24-h ambulatory blood pressure shows less variability than office measurements; however, the percentage of patients with a mean difference greater than +/- 5 mm Hg on repeat 24-h blood pressure measurement after 1 week is still surprisingly high (49.3%, systolic; 52.1%, diastolic). European trials are in progress to assess the prognosis of hypertension assessed by ambulatory compared with office blood pressure. Ambulatory blood pressure monitoring has been restricted for use in several clinical situations and is not used for the routine evaluation and management of hypertension.

Adult↗
PubMed1995

Low-dose drug combination therapy: an alternative first-line approach to hypertension treatment.

To investigate the concept that the initial treatment of hypertension with low doses of two antihypertensives that have different modes of action and additive effects may achieve control of blood pressure and minimize the dose-dependent adverse effects seen with conventional monotherapy, a randomized, double-blind parallel group dose-escalation study was conducted. After a 4 to 5 week placebo washout period, 218 men and women with diastolic blood pressure between 95 and 114 mm Hg were randomly allocated to take: amlodipine (2.5 to 10 mg), enalapril (5 to 20 mg), and the low-dose combination of bisoprolol (2.5 to 10 mg) with 6.25 mg of hydrochlorothiazide (HCTZ). All drugs were administered once daily, titrated to optimal response, and taken for a total of 12 weeks. Blood pressure was measured 24 hours after dose. The response rates (either a diastolic blood pressure < or = 90 mm Hg or a decrease of diastolic pressure > or = 10 mm Hg) were 71% for bisoprolol-6.25 mg HCTZ, 69% for amlodipine, and 45% for enalapril. The mean decreases in systolic/diastolic blood pressure from baseline were 13.4/10.7, 12.8/10.2, and 7.3/6.6 mm Hg for bisoprolol-6.25 mg HCTZ, amlodipine, and enalapril, respectively. The mean change with enalapril was less than the other drugs (p < 0.01), although the once-daily dosing of enalapril and the maximum dose of 20 mg might not have been optimal for this agent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

American National Standard for nonautomated sphygmomanometers. Summary report.

The Association for the Advancement of Medical Instrumentation develops voluntary standards for medical devices so that manufacturers might provide information on their product and basic safety and performance criteria that should be considered in qualifying the instrument for clinical use. American National Standards are generated through a consensus process by committees of experts in research, development, and design from user, industry, and government communities. Draft standards are made available for public review and become American National Standards after review by the American National Standards Institute. This report is a summary of the American National Standard that establishes both the safety and performance requirements of pneumatic and other nonautomated sphygmomanometers (especially mercury gravity and aneroid sphygmomanometers) used in the indirect measurement of blood pressure. This standard was developed by a consensus panel from academia, industry, and government; it updates the previous standard approved by the American National Standards Institute in 1986. This summary report does not cover all of the provisions of the revised 1994 American National Standard, thus users, researchers, and instrument designers should refer to the standard for detailed requirements.

Blood Pressure Determination↗
PubMed1995

Magnetic resonance imaging compared to echocardiography to assess left ventricular mass in the hypertensive patient.

Echocardiography (ECHO) is useful to document changes in left ventricular mass (LVM) in groups of patients, but may be too variable for use in the individual patient. Magnetic resonance imaging (MRI) may be a more precise and reliable method to quantify the mass of the left ventricule. This study reports the accuracy, precision, and reliability of LVM estimates by MRI as compared to data obtained by ECHO in hypertensive patients. Accuracy referred to the comparison of LVM by MRI to anatomical LVM determined by autopsy. Precision was examined using 34 duplicate MRI images and by blindly reading 24 duplicate M-mode strips. Reliability was assessed by MRI in four subjects over 2 months, and by ECHO in 22 hypertensive patients over 2 weeks. Agreement between MRI and ECHO estimates of LVM was determined in the same 17 hypertensive patients using linear regression. MRI LVM estimates were within 17.5 g (95% CI) of the true LVM. The linear agreement between MRI and ECHO estimates of LVM could be described by the equation MRI = 0.61 x ECHO + 49.57 (r = 0.63, P < .01). The precision of LVM by MRI (11 g) was over twice that observed with ECHO (26 g). The reliability of MRI LVM estimates was more consistent (+/- 8 g) than that for ECHO (+/- 49 g). MRI appears to be a more precise and reliable method for measuring LVM, and would be more suitable than ECHO for the clinical evaluation of the individual patient.

Adult↗
PubMed1995

Ambulatory blood pressure monitoring in the diagnosis of hypertension.

Noninvasive ambulatory blood pressure monitoring is a tool that may be useful for selected patients. Interest in the technology has increased because of errors and variability in clinic measurements and because of white-coat hypertension. White-coat hypertension is not benign and is associated with increased left ventricular mass and altered lipid and endocrine profiles. Ambulatory blood pressure may be useful in white-coat, borderline, and drug-resistant hypertension. Patient hook-up requires a skilled technician to adjust and calibrate the equipment and instruct the patient. Blood pressure and heart rate data should be analyzed with respect to diary entries. Observations of the diurnal curve, 24-hour, daytime, and nighttime mean blood pressure and blood pressure load are the key items in report interpretation. A 24-hour blood pressure mean of at least 134-139/84-87 mm Hg is probably indicative of hypertension. A blood pressure load of greater than 40% predicts target-organ damage. A reduced nocturnal decline is seen in many diseases but more importantly is associated with more target organ damage. The equipment used for ambulatory monitoring should be independently validated against the most recent AAMI or British Hypertension Society protocols. The performance of these devices is acceptable at rest but poor with activity. Group test-retest performance is excellent, but there is much more variability in individual patients. The variability in individuals is probably due to differences in activity and behavior. This has implications in the interpretation of ambulatory blood pressure parameters. Complications are most often related to excess repetitive inflations. Ambulatory blood pressure monitoring affects sleep mildly. Ongoing studies will define the place of ambulatory blood pressure monitoring in the care of patients.

Blood Pressure Monitoring, Ambulatory↗
PubMed1994

Hypertension: not solely a blood pressure problem.

Patients with hypertension are more likely than those with normal blood pressure to have vascular disease, target-organ disease, and concomitant disorders, such as dyslipidemia, diabetes mellitus, obesity, arthritis, and renal and liver function problems. The authors describe how to correctly diagnose hypertension, identify associated problems, and arrive at the best therapeutic approach for the individual patient.

Humans↗