Our library of drug research abstracts drawn from the medical literature is updated on a regular schedule, and you can be assured that new hygroton research articles will be listed here shortly after becoming available to us.
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Curr Med Res Opin. 2008 Jun; 24(6): 1771-9
Pareek A, Karnik N, Salagre SB, Zawar SD, Joglekar VK, Chandurkar N, Naik GS
OBJECTIVE: To compare the efficacy and safety of low-dose chlorthalidone + atenolol combination with atenolol and atenolol + amlodipine combination in stage I hypertensive patients uncontrolled on active run-in monotherapy. METHODS: Newly diagnosed stage I hypertensive patients were randomized to active run-in monotherapy either with atenolol 25 mg (98/300) or chlorthalidone 6.25 mg (100/300) or amlodipine 2.5 mg (102/300). A total of 282/300 patients (atenolol 92, chlorthalidone 91, amlodipine 99) completed the active run-in phase successfully. Patients uncontrolled on active run-in monotherapy (atenolol 33, chlorthalidone 45, amlodipine 47) received the study treatment, namely atenolol 50 mg alone, chlorthalidone 6.25 mg+atenolol 25 mg and atenolol 25 mg+amlodipine 2.5 mg, respectively. Efficacy of the therapy was evaluated by BP measurement at weeks 12 and 20 post-therapy. RESULTS: Post-active run-in monotherapies, the study treatment groups showed a significant fall in mean SBP and DBP from baseline (p
Hypertension. 2008 Jun; 51(6): 1552-6
Vagaonescu TD, Wilson AC, Kostis JB
We performed a post hoc analysis of the Systolic Hypertension in the Elderly Program database to assess the incidence of atrial fibrillation in the elderly hypertensive population, its influence on cardiovascular events, and whether antihypertensive treatment can prevent its onset. The Systolic Hypertension in the Elderly Program was a double-blind placebo-controlled trial in 4736 subjects with isolated systolic hypertension aged >or=60 years. Atrial fibrillation was an exclusion criterion from the trial. Participants were randomly assigned to stepped care treatment with chlorthalidone and atenolol (n=2365) or placebo (n=2371). The occurrence of atrial fibrillation and cardiovascular events over 4.7 years as well as the determination of cause of death at 4.7 and 14.3 years were followed. Ninety-eight subjects (2.06%) developed atrial fibrillation over 4.7 years mean follow-up, without significant difference between treated and placebo groups. Atrial fibrillation increased the risk for: total cardiovascular events (RR 1.69; 95% CI 1.21 to 2.36), rapid death (RR 3.29; 95% CI 1.08 to 10.00), total (RR 5.10; 95% CI 3.12 to 8.37) and nonfatal left ventricular failure (RR 5.31; 95% CI 3.09 to 9.13). All-cause and total cardiovascular death were significantly increased in the atrial fibrillation group at 4.7 years (HR 3.44; 95% CI 2.18 to 5.42; HR 2.39; 95% CI 1.05 to 5.43) and 14.3 years follow-up (HR 2.33; 95% CI 1.83 to 2.98; HR 2.21; 95% CI 1.54 to 3.17). Atrial fibrillation increased the risk for total cardiovascular events, rapid death, and left ventricular failure. All-cause mortality and total cardiovascular mortality were significantly increased in hypertensives with atrial fibrillation at 4.7 and 14.3 years follow-up.
Bioorg Med Chem Lett. 2008 Apr 15; 18(8): 2567-73
Temperini C, Cecchi A, Scozzafava A, Supuran CT
Diuretics such as hydrochlorothiazide, hydroflumethiazide, quinethazone, metolazone, chlorthalidone, indapamide, furosemide, and bumetanide containing primary sulfamoyl moieties were reevaluated as inhibitors of 12 human carbonic anhydrases (hCAs, EC 4.2.1.1). These drugs considerably inhibit (low nanomolar range) some CA isozymes involved in critical physiologic processes, among the 16 present in vertebrates, for example, metolazone against CA VII, XII, and XIII, chlorthalidone against CA VB, VII, IX, XII, and XIII, indapamide against CA VII, IX, XII, and XIII, furosemide against CA I, II, and XIV, and bumetanide against CA IX and XII. The X-ray crystal structure of the hCA II-indapamide adduct was also resolved at high resolution.
Diuretics: from classical carbonic anhydrase inhibitors to novel applications of the sulfonamides.
Curr Pharm Des. 2008; 14(7): 641-8
Supuran CT
The widely clinically used benzothiadiazines and high ceiling diuretics, such as hydrochlorothiazide, hydroflumethiazide, quinethazone, metolazone, chlorthalidone, indapamide, furosemide and bumetanide, contain SO(2)NH(2) moieties acting as an effective zinc-binding function in carbonic anhydrases (CAs, EC 4.2.1.1) inhibitors. These drugs were launched in a period when only isoform CA II was known and considered physiologically/pharmacologically relevant. Although acting as moderate-weak inhibitors of CA II, all these drugs considerably inhibit other CA isozymes known nowadays to be involved in critical physiologic processes, among the 16 CAs present in vertebrates. Some low nanomolar (or even subnanomolar) inhibitors against such isoforms were recently detected, such as metholazone against CA VII, XII and XIII, chlorthalidone against CA VB, VII, IX, XII and XIII, indapamide against CA VII, IX, XII and XIII, furosemide against CA I, II and XIV, and bumethanide against CA IX and XII. The X-ray crystal structure of the CA II-indapamide adduct was also reported recently, revealing interesting aspects useful for the drug design of CA inhibitors. It has also been proposed that the recently observed beneficial effect of indapamide for the treatment of patients with hypertension and type 2 diabetes might be due to its potent inhibition of CA isoforms present in kidneys and blood vessels, which would thus explain both the blood pressure lowering effects as well as organ-protective activity of the drug. Thus, these old drugs may be useful as leads for new applications.
Stroke. 2008 Apr; 39(4): 1084-9
Patel AB, Kostis JB, Wilson AC, Shea ML, Pressel SL, Davis BR
BACKGROUND AND PURPOSE: Epidemiologic studies have demonstrated that hypertension increases the risk of stroke, and clinical trials have shown that antihypertensive therapy reduces this risk. Incident stroke was significantly decreased by treatment in the Systolic Hypertension in Elderly Program (SHEP) Trial, but the reduction in fatal events was not statistically significant. METHODS: Vital status was determined for 4736 SHEP participants by matching to the National Death Index. We assessed the impact of antihypertensive treatment, stroke, and transient ischemic attacks (TIAs) during SHEP on long-term (mean, 14.3 years) mortality. RESULTS: Treatment with a chlorthalidone-based antihypertensive regimen significantly reduced the risk of cardiovascular death (adjusted relative risk [RR]=0.86; 95% CI, 0.76 to 0.98, P=0.026) in the SHEP cohort without a significant (P=0.39) interaction with stroke status. Patients who sustained a stroke during SHEP had significantly higher all-cause mortality at the 14.3-year mean follow-up: 65.6% compared with 40.6% among those free of stroke or TIA (adjusted RR=1.97; 95% CI, 1.67 to 2.33). They also were at higher risk for cardiovascular death (RR=2.00; 95% CI, 1.58 to 2.53) and stroke death (RR=2.94; 95% CI, 1.87 to 4.64). TIA was not significantly associated with increased total mortality (RR=1.13; 95% CI, 0.88 to 1.44), cardiovascular death (RR=1.30; 95% CI, 0.94 to 1.81), or stroke death (RR=1.76; 95% CI, 0.95 to 3.26). CONCLUSIONS: In SHEP, chlorthalidone-based treatment reduced the risk of cardiovascular death after 14 years of extended follow-up. Nearly two thirds of elderly persons with isolated systolic hypertension who experienced stroke died within 14 years.
Thiazide diuretics, endothelial function, and vascular oxidative stress.
J Hypertens. 2008 Mar; 26(3): 494-500
Zhou MS, Schulman IH, Jaimes EA, Raij L
OBJECTIVES: Increased endothelial production of reactive oxygen species and decreased nitric oxide bioactivity, associated with the upregulation of monocyte chemoattractant protein (MCP)-1 and lectin-like oxidized low-density lipoprotein receptor (LOX)-1, link hypertension with atherogenesis. We investigated whether the beneficial effects of thiazide diuretics are exclusively related to a reduction in the biomechanical stress of hypertension or are also endowed with pleiotropic vasculoprotective effects that are independent of their effect upon blood pressure. METHODS: Dahl salt-sensitive (DSS) rats, a paradigm of human salt-sensitive hypertension, were given a diet with normal salt (0.5% NaCl), high salt (4% NaCl), or a high salt diet plus either hydrochlorothiazide 75 mg/l, chlorthalidone 37 or 75 mg/l in their drinking water for 6 weeks. We determined systolic blood pressure (SBP), left ventricular hypertrophy (LVH), proteinuria, aortic superoxide anion (O2(-)) production, endothelium-dependent relaxation (EDR) to acetylcholine, and aortic angiotensin II type 1 (AT1) receptor, LOX-1, and MCP-1 messenger RNA expression (by real-time polymerase chain reaction). RESULTS: DSS rats on a high salt diet developed hypertension, LVH, proteinuria, increased production of aortic O2(-) (106%), impaired EDR, and aortic upregulation of AT1 receptor (198%), LOX-1 (135%), and MCP-1 (145%). Hydrochlorothiazide as well as the high and low dose of chlorthalidone reduced SBP, LVH, and proteinuria, but did not reduce O2(-) production, AT1 receptor, LOX-1, or MCP-1 expression, or improved EDR. CONCLUSIONS: This study demonstrates that thiazide diuretics do not reduce oxidative stress, improve endothelial function, or prevent the expression of pro-atherogenic molecules. We conclude that thiazide diuretics may not fully provide long-term global cardiovascular protection beyond lowering blood pressure.
Effects of antihypertensive drug treatment on the risk of dementia and cognitive impairment.
Pharmacotherapy. 2008 Mar; 28(3): 366-75
Poon IO
Dementia is a common and serious health problem that affects 33 million persons globally. With the increase in life expectancy, the prevalence of dementia is expected to reach 81.1 million persons by 2040. Dementia impairs quality of life and is associated with profound disease burden, morbidity, and mortality in both patients and caregivers. Therefore, identifying measures to prevent dementia is a research priority. Midlife hypertension has increased the risk of dementia in large prospective cohort studies. Researchers have investigated the blood pressure-lowering effects of antihypertensive drugs on the incidence of dementia. Although prospective cohort studies have shown that use of antihypertensive drugs was associated with a reduced rate of cognitive impairment and dementia, these studies were not placebo controlled. Four randomized, placebo-controlled studies-the Systolic Hypertension in Europe (Syst-Eur) study, Study on Cognition and Prognosis in the Elderly (SCOPE), Systolic Hypertension in the Elderly Program (SHEP), and Perindopril Protection Against Recurrent Stroke Study (PROGRESS)-investigated the effects of antihypertensive agents on the incidence of dementia. The Syst-Eur study found that active treatment with nitrendipine, enalapril, and/or hydrochlorothiazide reduced the rate of dementia by 50% compared with placebo (p=0.05). The PROGRESS study showed that active treatment with perindopril and indapamide was associated with reduced cognitive decline compared with placebo (risk ratio 19%, p=0.01). In contrast, the SCOPE study (candesartan or hydrochlorothiazide vs placebo) and the SHEP trial (chlorthalidone, atenolol, or reserpine vs placebo) found no significant difference between the active treatment and placebo groups on the incidence of dementia. Some researchers have suggested that certain antihypertensive drug classes, such as angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, diuretics, and calcium channel blockers, may offer benefit in reducing dementia risk in addition to their blood pressure-lowering effect. Further prospective randomized studies comparing different antihypertensive classes are needed to provide more evidence regarding the effects of antihypertensive drugs on dementia risk and to determine whether certain antihypertensive classes provide greater benefits than others.
HPLC method for the simultaneous determination of atenolol and chlorthalidone in human breast milk.
J Sep Sci. 2008 Mar; 31(4): 677-82
El-Gindy A, Sallam S, Abdel-Salam RA
A high-performance liquid chromatographic method was optimized and validated for the determination of atenolol and chlorthalidone (CT) in human breast milk. The milk samples were extracted and purified using ACN and phosphoric acid for precipitation of proteins followed by removal of ACN and milk fats by extraction with methylene chloride. The samples were applied, after an extraction procedure, to a cyanide column using a mobile phase consisting of ACN/water (35:65 v/v) and buffered at pH 4.0 with flow rate of 1.0 mL/min. Quantitation was achieved with UV detection at 225 nm using guaifenesin as the internal standard. The effectiveness of protein precipitation and clean up procedure were investigated. The method was validated over the range of 0.3-20 microg/mL for atenolol and 0.25-5 microg/mL for CT.
J Gen Intern Med. 2008 May; 23(5): 509-16
Heidenreich PA, Davis BR, Cutler JA, Furberg CD, Lairson DR, Shlipak MG, Pressel SL, Nwachuku C, Goldman L
OBJECTIVE: To evaluate the cost-effectiveness of first-line treatments for hypertension. BACKGROUND: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) found that first-line treatment with lisinopril or amlodipine was not significantly superior to chlorthalidone in terms of the primary endpoint, so differences in costs may be critical for optimizing decision-making. METHODS: Cost-effectiveness analysis was performed using bootstrap resampling to evaluate uncertainty. RESULTS: Over a patient's lifetime, chlorthalidone was always least expensive (mean $4,802 less than amlodipine, $3,700 less than lisinopril). Amlodipine provided more life-years (LYs) than chlorthalidone in 84% of bootstrap samples (mean 37 days) at an incremental cost-effectiveness ratio of $48,400 per LY gained. Lisinopril provided fewer LYs than chlorthalidone in 55% of bootstrap samples (mean 7-day loss) despite a higher cost. At a threshold of $50,000 per LY gained, amlodipine was preferred in 50%, chlorthalidone in 40%, and lisinopril in 10% of bootstrap samples, but these findings were highly sensitive to the cost of amlodipine and the cost-effectiveness threshold chosen. Incorporating quality of life did not appreciably alter the results. Overall, no reasonable combination of assumptions led to 1 treatment being preferred in over 90% of bootstrap samples. CONCLUSIONS: Initial treatment with chlorthalidone is less expensive than lisinopril or amlodipine, but amlodipine provided a nonsignificantly greater survival benefit and may be a cost-effective alternative. A randomized trial with power to exclude "clinically important" differences in survival will often have inadequate power to determine the most cost-effective treatment.
Arch Intern Med. 2008 Jan 28; 168(2): 207-17
Wright JT, Harris-Haywood S, Pressel S, Barzilay J, Baimbridge C, Bareis CJ, Basile JN, Black HR, Dart R, Gupta AK, Hamilton BP, Einhorn PT, Haywood LJ, Jafri SZ, Louis GT, Whelton PK, Scott CL, Simmons DL, Stanford C, Davis BR
BACKGROUND: Antihypertensive drugs with favorable metabolic effects are advocated for first-line therapy in hypertensive patients with metabolic/cardiometabolic syndrome (MetS). We compared outcomes by race in hypertensive individuals with and without MetS treated with a thiazide-type diuretic (chlorthalidone), a calcium channel blocker (amlodipine besylate), an alpha-blocker (doxazosin mesylate), or an angiotensin-converting enzyme inhibitor (lisinopril). METHODS: A subgroup analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), a randomized, double-blind hypertension treatment trial of 42 418 participants. We defined MetS as hypertension plus at least 2 of the following: fasting serum glucose level of at least 100 mg/dL, body mass index (calculated as weight in kilograms divided by height in meters squared) of at least 30, fasting triglyceride levels of at least 150 mg/dL, and high-density lipoprotein cholesterol levels of less than 40 mg/dL in men or less than 50 mg/dL in women. RESULTS: Significantly higher rates of heart failure were consistent across all treatment comparisons in those with MetS. Relative risks (RRs) were 1.50 (95% confidence interval, 1.18-1.90), 1.49 (1.17-1.90), and 1.88 (1.42-2.47) in black participants and 1.25 (1.06-1.47), 1.20 (1.01-1.41), and 1.82 (1.51-2.19) in nonblack participants for amlodipine, lisinopril, and doxazosin comparisons with chlorthalidone, respectively. Higher rates for combined cardiovascular disease were observed with lisinopril-chlorthalidone (RRs, 1.24 [1.09-1.40] and 1.10 [1.02-1.19], respectively) and doxazosin-chlorthalidone comparisons (RRs, 1.37 [1.19-1.58] and 1.18 [1.08-1.30], respectively) in black and nonblack participants with MetS. Higher rates of stroke were seen in black participants only (RR, 1.37 [1.07-1.76] for the lisinopril-chlorthalidone comparison, and RR, 1.49 [1.09-2.03] for the doxazosin-chlorthalidone comparison). Black patients with MetS also had higher rates of end-stage renal disease (RR, 1.70 [1.13-2.55]) with lisinopril compared with chlorthalidone. CONCLUSIONS: The ALLHAT findings fail to support the preference for calcium channel blockers, alpha-blockers, or angiotensin-converting enzyme inhibitors compared with thiazide-type diuretics in patients with the MetS, despite their more favorable metabolic profiles. This was particularly true for black participants.