Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

ISH is a distinct pathogenetic entity defined by SBP readings of greater than or equal to 160 and DBP less than 90 mmHg. The etiology, although not well understood, is in some manner related to a reduction in connective tissue elasticity of large blood vessels and an increase in aortic impedance or a decrease in aortic wall compliance. The pathophysiologic consequences include an increased resistance to systolic ejection of blood and a disproportionate increase in SBP. Although not directly related, there is an important increase in peripheral vascular resistance. The prevalence of ISH in several studies is about 7 percent in those over age 60 and increases with age to nearly 20 percent in those over age 80. There is higher prevalence in females and nonwhites. The guidelines for detection of ISH are similar to those for blood pressure evaluation in general. Precautions for detection and evaluation in the elderly include multiple blood pressure measurements in the fasting state and sitting and supine blood pressure measurements before and during therapy. Pseudohypertension, although rare, should be kept in mind. There is a clear risk associated with ISH for stroke, CVD, and premature death, which increases with age and rising levels of SBP. ISH can be controlled effectively with pharmacologic therapies. A reasonable goal is a 20 mmHg reduction in systolic pressure. Proof of reduced risk for stroke, CHD, and death in those with controlled ISH remains to be demonstrated. The SHEP pilot study has demonstrated feasibility of addressing this issue. The full-scale SHEP study addresses this issue and has completed recruitment of the desired sample size and is in follow-up phase. Scheduled completion is in 1991. While we wait for the SHEP full-scale trial results, the prudent approach is for nonpharmacologic therapy and use of pharmacologic agents in that group of patients who demonstrate a large cardiovascular risk burden or increasing symptoms specifically associated with hypertension. The decision to treat must be on an individual patient basis. Pharmacologic therapy is possible in most patients with few or no adverse effects. The "low and slow" approach to therapy is helpful in minimizing these adverse effects. Low-dose diuretics have been documented to be effective in blood pressure control. Chlorthalidone, 12.5 or 25 mg per day, is suggested. Other agents, such as beta-blockers, reserpine, ACE inhibitors, and calcium channel blockers, are best used as Step 2 agents.
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PMID:Systolic hypertension in the elderly: controlled or uncontrolled. 218 67

Antihypertensive therapy is well established to reduce hypertension-related morbidity and mortality, but the optimal first-step therapy is still controversial. The "Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial" (ALLHAT) should give such an answer. It is a randomised, double-blind, trial designed to determine whether treatment with either a calcium channel blocker or an angiotensin-converting enzyme inhibitor lowers the incidence of coronary heart disease (CHD) or other cardiovascular disease (CVD) events vs treatment with a diuretic. A total of 33,357 participants aged 55 years or older with mild to moderate hypertension and at least 1 other CHD risk factor were randomly assigned to receive chlorthalidone (12.5 to 25 mg/day; n = 15,255), amlodipine (2.5 to 10 mg/day; n = 9,048) or lisinopril (10 to 40 mg; n = 9,054). The primary outcome combined both fatal CHD and non-fatal myocardial infarction, analyzed by intent-to-treat. Secondary outcomes were all-causes mortality, stroke, combined CHD (primary outcome, coronary revascularization, or angina with hospitalization), and combined CVD (combined CHD, stroke, treated angina without hospitalization, heart failure and peripheral arterial disease). Chlorthalidone was slightly more effective in reducing systolic pressure while amlodipine reduced slightly more effectively diastolic blood pressure. After a mean follow up of 4.9 years, no differences were observed between the three treatments regarding both the primary outcome and the total mortality. Secondary outcomes were similar when comparing amlodipine vs chlorthalidone. A moderately higher 6-year incidence rate of clinically detected heart failure was observed with amlodipine, but without significant influence on mortality. For lisinopril vs chlorthalidone, lisinopril had slightly higher 6-year rates of combined CVD, stroke and heart failure. In conclusion, thiazide-type diuretics are superior in preventing one or more major forms of CVD and offer the advantage to be cheaper. They should be preferred for first-step antihypertensive therapy. However, to reach the recommended blood pressure target, most patients should receive a combination of antihypertensive compounds. Such a combination should always comprise a diuretic agent, in absence of contra-indications.
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PMID:[Clinical study of the month. Which initial antihypertensive? Results from the ALLHAT trial]. 1264 99

Low-dose thiazide-type diuretics are recommended as initial therapy for most hypertensive patients. Chlorthalidone has significantly reduced stroke and cardiovascular end points in several landmark trials; however, hydrochlorothiazide remains favored in practice. Most clinicians assume that the drugs are interchangeable, but their antihypertensive effects at lower doses have not been directly compared. We conducted a randomized, single-blinded, 8-week active treatment, crossover study comparing chlorthalidone 12.5 mg/day (force-titrated to 25 mg/day) and hydrochlorothiazide 25 mg/day (force-titrated to 50 mg/day) in untreated hypertensive patients. The main outcome, 24-hour ambulatory blood pressure (BP) monitoring, was assessed at baseline and week 8, along with standard office BP readings every 2 weeks. Thirty patients completed the first active treatment period, whereas 24 patients completed both. An order-drug-time interaction was observed with chlorthalidone; therefore, data from only the first active treatment period was considered. Week 8 ambulatory BPs indicated a greater reduction from baseline in systolic BP with chlorthalidone 25 mg/day compared with hydrochlorothiazide 50 mg/day (24-hour mean = -12.4+/-1.8 mm Hg versus -7.4+/-1.7 mm Hg; P=0.054; nighttime mean = -13.5+/-1.9 mm Hg versus -6.4+/-1.8 mm Hg; P=0.009). Office systolic BP reduction was lower at week 2 for chlorthalidone 12.5 mg/day versus hydrochlorothiazide 25 mg/day (-15.7+/-2.2 mm Hg versus -4.5+/-2.1 mm Hg; P=0.001); however, by week 8, reductions were statistically similar (-17.1+/-3.7 versus -10.8+/-3.5; P=0.84). Within recommended doses, chlorthalidone is more effective in lowering systolic BPs than hydrochlorothiazide, as evidenced by 24-hour ambulatory BPs. These differences were not apparent with office BP measurements.
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PMID:Comparative antihypertensive effects of hydrochlorothiazide and chlorthalidone on ambulatory and office blood pressure. 1644 94

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is reevaluated considering information from new clinical trials, meta-analyses, and recent subgroup and explanatory analyses from ALLHAT, especially those regarding heart failure (HF) and the association of drug treatment with new-onset diabetes mellitus (DM) and its cardiovascular disease (CVD) consequences. Chlorthalidone was superior to (1) doxazosin mesylate in preventing combined CVD (CCVD) (risk ratio [RR], 1.20; 95% confidence interval [CI], 1.13-1.27), especially HF (RR, 1.80; 95% CI, 1.40-2.22) and stroke (RR, 1.26; 95% CI, 1.10-1.46); (2) lisinopril in preventing CCVD (RR, 1.10; 95% CI, 1.05-1.16), including stroke (in black persons only) and HF (RR, 1.20; 95% CI, 1.09-1.34); and (3) amlodipine besylate in preventing HF, overall (by 28%) and in hospitalized or fatal cases (by 26%). Central independent blinded reassessment of HF hospitalizations confirmed each comparison. Results were consistent by age, sex, race (except for stroke and CCVD), DM status, metabolic syndrome status, and renal function level. Neither amlodipine nor lisinopril was superior to chlorthalidone in preventing end-stage renal disease overall, by DM status, or by renal function level. In the chlorthalidone arm, new-onset DM was not significantly associated with CCVD (RR, 0.96; 95% CI, 0.88-2.42). Evidence from subsequent analyses of ALLHAT and other clinical outcome trials confirm that neither alpha-blockers, angiotensin-converting enzyme inhibitors, nor calcium channel blockers surpass thiazide-type diuretics (at appropriate dosage) as initial therapy for reduction of cardiovascular or renal risk. Thiazides are superior in preventing HF, and new-onset DM associated with thiazides does not increase CVD outcomes.
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PMID:ALLHAT findings revisited in the context of subsequent analyses, other trials, and meta-analyses. 1985 42

Hypertension is a chronic condition leading to increased stress on the heart and blood vessels, a critical risk factor for clinically significant events such as myocardial infarction heart failure, stroke and death. Chlorthalidone and hydrochlorothiazide are first-line antihypertensive agents for most patients with hypertension. The aim of our meta-analysis was to compare the efficacy and safety of both therapies in patients with hypertension. Searches of electronic databases PubMed, MEDLINE, Scopus, PsycInfo and eLIBRARY.ru, were performed. We used network meta-analysis to combine direct and indirect evidence. Forest plots and closed loops depict estimated results from studies included in our meta-analysis. Of 1289 identified sources, only 37 were included in our meta-analysis. Our analysis has demonstrated a slight superiority for chlorthalidone regarding SBP and not statistically significant differences regarding DBP. Simultaneously, hydrochlorothiazide seems to be a safer choice of therapy, as evidenced by the levels of serum potassium. The two diuretics can be used interchangeably.
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PMID:Network meta-analysis of efficacy and safety of chlorthalidone and hydrochlorothiazide in hypertensive patients. 3290 66