Effect of antihypertensive agents on sleep apnea and ambulatory blood pressure in patients with hypertension: A randomized controlled trial.

BACKGROUND: Obstructive sleep apnea (OSA) and hypertension are common conditions that may be linked through sympathetic activation and water retention. We hypothesized that diuretics, which reduce the body water content, may be more effective than amlodipine, a blood pressure (BP)-lowering agent implicated with edema, in controlling OSA in patients with hypertension. We also aimed to compare the effects of these treatments on ambulatory blood pressure monitoring (ABPM). METHODS: In a randomized, double-blind clinical trial, we compared the effects of chlorthalidone/amiloride 25/5 mg with amlodipine 10 mg on OSA measured by portable sleep monitor and BP measured by ABPM. The study included participants older than 40 who had moderate OSA (10-40 apneas/hour of sleep) and BP within the systolic range of 140-159 mmHg or diastolic range of 90-99 mmHg. RESULTS: The individuals in the experimental groups were comparable in age, gender, and other relevant characteristics. Neither the combination of diuretics nor amlodipine alone reduced the AHI after 8 weeks of treatment (AHI 26.3 with diuretics and 25.0 with amlodipine. P = 0.713). Both treatments significantly lowered office, 24-h, and nighttime ABP, but the two groups had no significant difference. CONCLUSION: Chlorthalidone associated with amiloride and amlodipine are ineffective in decreasing the frequency of sleep apnea episodes in patients with moderate OSA and hypertension. Both treatments have comparable effects in lowering both office and ambulatory blood pressure. The notion that treatments could offer benefits for both OSA and hypertension remains to be demonstrated. TRIAL REGISTRATION CLINICALTRIALS. GOV IDENTIFIER: NCT01896661.

Pharmacological interventions for asymptomatic carotid stenosis.

BACKGROUND: Carotid artery stenosis is narrowing of the carotid arteries. Asymptomatic carotid stenosis is when this narrowing occurs in people without a history or symptoms of this disease. It is caused by atherosclerosis; that is, the build-up of fats, cholesterol, and other substances in and on the artery walls. Atherosclerosis is more likely to occur in people with several risk factors, such as diabetes, hypertension, hyperlipidaemia, and smoking. As this damage can develop without symptoms, the first symptom can be a fatal or disabling stroke, known as ischaemic stroke. Carotid stenosis leading to ischaemic stroke is most common in men older than 70 years. Ischaemic stroke is a worldwide public health problem. OBJECTIVES: To assess the effects of pharmacological interventions for the treatment of asymptomatic carotid stenosis in preventing neurological impairment, ipsilateral major or disabling stroke, death, major bleeding, and other outcomes. SEARCH METHODS: We searched the Cochrane Stroke Group trials register, CENTRAL, MEDLINE, Embase, two other databases, and three trials registers from their inception to 9 August 2022. We also checked the reference lists of any relevant systematic reviews identified and contacted specialists in the field for additional references to trials. SELECTION CRITERIA: We included all randomised controlled trials (RCTs), irrespective of publication status and language, comparing a pharmacological intervention to placebo, no treatment, or another pharmacological intervention for asymptomatic carotid stenosis. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. Two review authors independently extracted the data and assessed the risk of bias of the trials. A third author resolved disagreements when necessary. We assessed the evidence certainty for key outcomes using GRADE. MAIN RESULTS: We included 34 RCTs with 11,571 participants. Data for meta-analysis were available from only 22 studies with 6887 participants. The mean follow-up period was 2.5 years. None of the 34 included studies assessed neurological impairment and quality of life. Antiplatelet agent (acetylsalicylic acid) versus placebo Acetylsalicylic acid (1 study, 372 participants) may result in little to no difference in ipsilateral major or disabling stroke (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.47 to 2.47), stroke-related mortality (RR 1.40, 95% CI 0.54 to 3.59), progression of carotid stenosis (RR 1.16, 95% CI 0.79 to 1.71), and adverse events (RR 0.81, 95% CI 0.41 to 1.59), compared to placebo (all low-certainty evidence). The effect of acetylsalicylic acid on major bleeding is very uncertain (RR 0.98, 95% CI 0.06 to 15.53; very low-certainty evidence). The study did not measure neurological impairment or quality of life. Antihypertensive agents (metoprolol and chlorthalidone) versus placebo The antihypertensive agent, metoprolol, may result in no difference in ipsilateral major or disabling stroke (RR 0.14, 95% CI 0.02 to1.16; 1 study, 793 participants) and stroke-related mortality (RR 0.57, 95% CI 0.17 to 1.94; 1 study, 793 participants) compared to placebo (both low-certainty evidence). However, chlorthalidone may slow the progression of carotid stenosis (RR 0.45, 95% CI 0.23 to 0.91; 1 study, 129 participants; low-certainty evidence) compared to placebo. Neither study measured neurological impairment, major bleeding, adverse events, or quality of life. Anticoagulant agent (warfarin) versus placebo The evidence is very uncertain about the effects of warfarin (1 study, 919 participants) on major bleeding (RR 1.19, 95% CI 0.97 to 1.46; very low-certainty evidence), but it may reduce adverse events (RR 0.89, 95% CI 0.81 to 0.99; low-certainty evidence) compared to placebo. The study did not measure neurological impairment, ipsilateral major or disabling stroke, stroke-related mortality, progression of carotid stenosis, or quality of life. Lipid-lowering agents (atorvastatin, fluvastatin, lovastatin, pravastatin, probucol, and rosuvastatin) versus placebo or no treatment Lipid-lowering agents may result in little to no difference in ipsilateral major or disabling stroke (atorvastatin, lovastatin, pravastatin, and rosuvastatin; RR 0.36, 95% CI 0.09 to 1.53; 5 studies, 2235 participants) stroke-related mortality (lovastatin and pravastatin; RR 0.25, 95% CI 0.03 to 2.29; 2 studies, 1366 participants), and adverse events (fluvastatin, lovastatin, pravastatin, probucol, and rosuvastatin; RR 0.76, 95% CI 0.53 to1.10; 7 studies, 3726 participants) compared to placebo or no treatment (all low-certainty evidence). The studies did not measure neurological impairment, major bleeding, progression of carotid stenosis, or quality of life. AUTHORS' CONCLUSIONS: Although there is no high-certainty evidence to support pharmacological intervention, this does not mean that pharmacological treatments are ineffective in preventing ischaemic cerebral events, morbidity, and mortality. High-quality RCTs are needed to better inform the best medical treatment that may reduce the burden of carotid stenosis. In the interim, clinicians will have to use other sources of information.

Clortalidona para adultos com hipertensão arterial sistêmica com controle inadequado da pressão arterial / Chlorthalidone for adults with systemic arterial hypertension with inadequate blood pressure control

INTRODUÇÃO: A hipertensão arterial sistêmica (HAS), uma doença crônica, é um grave problema de saúde pública, caracterizada por níveis elevados e persistentes da pressão sanguínea, medidos em geral como uma razão da pressão arterial sistólica e diastólica (respectivamente maior ou igual a 140 mmHg; e/ou maior ou igual a 90 mmHg). Esta é uma doença altamente prevalente em todo o mundo. No Brasil, os números podem variar de acordo com a metodologia utilizada. Reportou-se na Pesquisa Nacional de Saúde de 2013, cujos dados são obtidos por autorrelato, a prevalência de hipertensão em 21% dos pacientes, mas ao considerar a aferição da pressão arterial e uso de medicamentos, o percentual de adultos com pressão arterial ≥140/90 mmHg foi de 32%. Sabe-se que a falta de controle da pressão arterial pode elevar o risco de ocorrência de eventos cardiovasculares, como infarto agudo do miocárdio, insuficiência cardíaca, acidente vascular cerebral, doenças renais, entre outros. Isso consequentemente pode causar problemas crônicos que reduzem a qualidade de vida do indivídu

Effect of the combination of bumetanide plus chlorthalidone on hypertension and volume overload in patients with chronic kidney disease stage 4-5 KDIGO without renal replacement therapy: a double-blind randomized HEBE-CKD trial.

BACKGROUND: The co-administration of loop diuretics with thiazide diuretics is a therapeutic strategy in patients with hypertension and volume overload. The aim of this study was to assess the efficacy and safety of treatment with bumetanide plus chlorthalidone in patients with chronic kidney disease (CKD) stage 4-5 KDIGO. METHODS: A double-blind randomized study was conducted. Patients were randomized into two groups: bumetanide plus chlorthalidone group (intervention) and the bumetanide plus placebo group (control) to evaluate differences in TBW, ECW and ECW/TBW between baseline and 30 Days of follow-up. Volume overload was defined as 'bioelectrical impedance analysis as fluid volume above the 90th percentile of a presumed healthy reference population. The study's registration number was NCT03923933. RESULTS: Thirty-two patients with a mean age of 57.2 ± 9.34 years and a median estimated glomerular filtration rate (eGFR) of 16.7 ml/min/1.73 m2 (2.2-29) were included. There was decreased volume overload in the liters of total body water (TBW) on Day 7 (intervention: -2.5 vs. control: -0.59, p = 0.003) and Day 30 (intervention: -5.3 vs. control: -0.07, p = 0.016); and in liters of extracellular water (ECW) on Day 7 (intervention: -1.58 vs. control: -0.43, p < 0.001) and Day 30 (intervention: -3.05 vs. control: -0.15, p < 0.000). There was also a decrease in systolic blood pressure on Day 7 (intervention: -18 vs. control: -7.5, p = 0.073) and Day 30 (intervention: -26.1 vs. control: -10, p = 0.028) and in diastolic blood pressure on Day 7 (intervention: -8.5 vs. control: -2.25, p = 0.059) and Day 30 (intervention: -13.5 vs. control: -3.4, p = 0.018). CONCLUSION: In CKD stage 4-5 KDIGO without renal replacement therapy, bumetanide in combination with chlorthalidone is more effective in treating volume overload and hypertension than bumetanide with placebo.

The Effect in Renal Function and Vascular Decongestion in Type 1 Cardiorenal Syndrome Treated with Two Strategies of Diuretics, a Pilot Randomized Trial.

AIM: The main treatment strategy in type 1 cardiorenal syndrome (CRS1) is vascular decongestion. It is probable that sequential blockage of the renal tubule with combined diuretics (CD) will obtain similar benefits compared with stepped-dose furosemide (SF). METHODS: In a pilot double-blind randomized controlled trial of CRS1 patients were allocated in a 1:1 fashion to SF or CD. The SF group received a continuous infusion of furosemide 100 mg during the first day, with daily incremental doses to 200 mg, 300 mg and 400 mg. The CD group received a combination of diuretics, including 4 consecutive days of oral chlorthalidone 50 mg, spironolactone 50 mg and infusion of furosemide 100 mg. The objectives were to assess renal function recovery and variables associated with vascular decongestion. RESULTS: From July 2017 to February 2020, 80 patients were randomized, 40 to the SF and 40 to the CD group. Groups were similar at baseline and had several very high-risk features. Their mean age was 59 ± 14.5 years, there were 37 men (46.2%). The primary endpoint occurred in 20% of the SF group and 15.2% of the DC group (p = 0.49). All secondary and exploratory endpoints were similar between groups. Adverse events occurred frequently (85%) with no differences between groups (p = 0.53). CONCLUSION: In patients with CRS1 and a high risk of resistance to diuretics, the use of CD compared to SF offers the same results in renal recovery, diuresis, vascular decongestion and adverse events, and it can be considered an alternative treatment. ClinicalTrials.gov with number NCT04393493 on 19/05/2020 retrospectively registered.

Effectiveness of chlorthalidone/amiloride versus losartan in patients with stage I hypertension and diabetes mellitus: results from the PREVER-treatment randomized controlled trial.

AIMS: To compare the blood pressure (BP)-lowering efficacy of a chlorthalidone/amiloride combination pill with losartan, during initial management of JNC 7 Stage I hypertension in patients with type 2 diabetes mellitus. METHODS: In an a priori subgroup analysis of a randomized, double-blind, controlled trial, volunteers aged 30-70 years, with stage I hypertension and diabetes mellitus, were randomized to 12.5/2.5 mg of chlorthalidone/amiloride (N = 47) or 50 mg of losartan (N = 50), and followed for 18 months in 21 clinical centers. If BP remained uncontrolled after three months, study medication dose was doubled, and if uncontrolled after six months, amlodipine (5 and 10 mg) and propranolol (40 and 80 mg BID) were added as open label drugs in a progressive fashion. RESULTS: Systolic BP decreased to a greater extent in participants allocated to diuretics compared to losartan (P < 0.001). After 18 months of follow-up, systolic BP was 128.4 ± 10.3 mmHg in the diuretic group versus 133.5 ± 8.0 in the losartan group (P < 0.01). In the diuretic group, 36 out of 43 participants (83.7%) had a JNC 7 normal BP, compared to 31/47 (66%) in the losartan group (P = 0.089). Serum cholesterol was higher in the diuretic arm at the end of the trial. Other biochemical parameters and reports of adverse events did not differ by treatment. CONCLUSIONS: Treatment of hypertension based on a combination of chlorthalidone and amiloride is more effective for BP lowering compared to losartan in patients with diabetes mellitus and hypertension. TRIAL REGISTRATION: Clinical trials registration number: NCT00971165.

Efficacy of chlorthalidone and hydrochlorothiazide in combination with amiloride in multiple doses on blood pressure in patients with primary hypertension: a protocol for a factorial randomized controlled trial.

BACKGROUND: Thiazide diuretics have demonstrated favorable blood pressure lowering efficacy, but the equivalent doses of their more common agents, chlorthalidone and hydrochlorothiazide, are still unclear. Further, concerns exist regarding adverse metabolic effects, which may be attenuated with the concomitant administration of a potassium-sparing diuretic, such as amiloride. This trial aims to investigate the efficacy of chlorthalidone and hydrochlorothiazide, in combination with amiloride at different doses, for initial management of patients with primary hypertension. METHODS/DESIGN: This is a factorial (2 × 2) randomized double-blinded clinical trial comparing the association of a thiazide diuretic (chlorthalidone 25 mg/day or hydrochlorothiazide 50 mg/day) with a potassium-sparing diuretic (amiloride 10 mg/day or amiloride 20 mg/day) in patients with primary hypertension. The primary outcome will be the mean change from baseline in 24-h systolic and diastolic blood pressure measured by ambulatory blood pressure monitoring. The secondary outcomes will be the mean change from baseline in daytime and nighttime systolic and diastolic blood pressure measured by ambulatory blood pressure monitoring, mean change from baseline in systolic and diastolic blood pressure measured by office blood pressure, incidence of adverse events, variation of laboratory parameters, and proportion of patients who achieved blood pressure control. The follow-up will last 12 weeks. For a P alpha of 0.05, power of 80%, standard deviation of 9 mmHg, and absolute difference of 6 mmHg on systolic blood pressure on 24-h ambulatory blood pressure monitoring, it will be necessary to study a total of 76 patients. The sample size will be increased by 10% to compensate for losses, resulting in 84 patients being randomized. DISCUSSION: Diuretics are pivotal drugs for the treatment of hypertension. Chlorthalidone and hydrochlorothiazide, in combination with amiloride in multiple doses, will be tested in terms of blood pressure lowering efficacy and safety. Since the intensity of blood pressure reduction is the major determinant of reduction in cardiovascular risk in hypertensive patients, this study will help to determine which combination of diuretics represents the most appropriate treatment for this population. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03928145. Registered on 25 April 2019. Last update on 29 April 2019.

The role of sodium alginate on the supersaturation state of the poorly soluble drug chlorthalidone.

Solid dispersions (SDs) of chlorthalidone (CTD) are promising systems to enhance drug dissolution rate, generate and maintain drug supersaturation levels in gastrointestinal fluids. In this work, SDs of CTD were prepared by spray drying using sodium alginate (SA) as carrier. Six formulations were prepared, varying the drug loading and composition, through the combination of SA with surfactants (sodium lauryl sulfate (SLS) or polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (SOL)). In all SDs, except when SA was used alone at low drug loading, CTD was in the amorphous form. At sink conditions, all SDs showed a faster dissolution rate than the crystalline drug. At non-sink conditions, the SDs prepared with SA and SLS at low drug loading exhibited the best performance to maintain supersaturating drug levels. All SDs, except those prepared with SA alone or SA-SLS at high drug loading, presented no drug recrystallization after 34 months of storage.

Investigation of novel supersaturating drug delivery systems of chlorthalidone: The use of polymer-surfactant complex as an effective carrier in solid dispersions.

Supersaturating drug delivery systems (SDDS), as solid dispersions (SDs), stand out among strategies to enhance bioavailability of poorly soluble drugs. After oral administration, their dissolution in gastrointestinal fluids often leads to supersaturation, which drives to a rapid and sustained absorption. Polymers and surfactants play important roles in SDs through inhibiting precipitation caused by transitions from amorphous into crystalline form, in supersaturated solutions, and also through improving SDs physical stability. Novel chlorthalidone SDs, a BCS IV drug, were developed using polymeric and non-polymeric carriers, specially a polymer-surfactant complex. SDs drug releases were evaluated using sink and non-sink conditions in water and biorelevant medium. Their physical stability was also monitored under different storage conditions. Polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (SOL), sodium lauryl sulfate (SLS) and a combination of both showed promising results in apparent solubility studies, and therefore they were selected to compose the spray dried SDs. Dissolution studies demonstrated the SOL-SLS complex potential for providing chlorthalidone fast release (>80% in 15min), producing and maintaining in vitro supersaturation. This formulation comprising high drug loading (75%) reached a high supersaturation degree under non-sink condition (up to 6-fold the equilibrium solubility) once maintained for 6h in biorelevant medium. In addition, this SD presented better physical stability when compared to the chlorthalidone neat amorphous. The SOL-SLS complex impacts positively on chlorthalidone release and physical stability, highlighting its potential as carrier in SDDS of a poorly soluble drug.

Echocardiographic Left Ventricular Reverse Remodeling After 18 Months of Antihypertensive Treatment in Stage I Hypertension. Results From the Prever-Treatment Study.

BACKGROUND: Antihypertensive treatment improves echocardiographic parameters of hypertensive target organ damage in stage II hypertension, but less is known about the effects in stage I hypertension. METHODS: In a cohort study nested in the randomized double-blind trial PREVER-treatment, 2-dimensional echocardiograms were performed in 110 individuals, aged 54.8 ± 7.9 years-old, with stage I hypertension at baseline and after 18 months of treatment with chlorthalidone/amiloride or losartan. RESULTS: At baseline, 66 (60%) participants had concentric remodeling. After antihypertensive treatment, systolic (SBP) and diastolic blood pressure (BP) were reduced from 141/90 to 130/83 mm Hg (P = 0.009). There was a significant reduction in left ventricular (LV) mass (LVM) index (82.7 ± 17.1 to 79.2 ± 17.5 g/m2; P = 0.005) and relative wall thickness (0.45 ± 0.06 to 0.42 ± 0.05; P < 0.001), increasing the proportion of participants with normal LV geometry (31% to 49%, P = 0.006). Left atrial (LA) volume index reduced (26.8 ± 7.3 to 24.9 ± 6.5 ml/m2; P = 0.001), and mitral E-wave deceleration time increased (230 ± 46 to 247 ± 67 ms; P = 0.005), but there was no change in other parameters of diastolic function. LVM reduction was significantly higher in the 2 higher tertiles of SBP reduction compared to the lower tertile. CONCLUSIONS: Treatment of patients with stage I hypertension for 18 months promotes favorable effects in the LA and LV remodeling. This improvement in cardiac end-organ damage might be associated with reduction of long term clinical consequences of hypertensive cardiomyopathy, particularly heart failure with preserved ejection fraction.

Avaliação da qualidade de medicamentos contendo clortalidona / Quality Assessment of medication containing chlorthalidone

Os diuréticos são a classe de fármacos mais utilizados no tratamento da hipertensão devido a sua eficácia terapêutica e ao baixo custo. Isto faz com que uma grande variedade de medicamentos esteja disponível no comercio e atrelado a este fator muitas empresas tem seus lotes de medicamentos suspensos devido a desvios de qualidade e das modificações realizadas nas formulações após o seu registro. A clortalidona é um diurético tiazídico indicada para o tratamento de hipertensão arterial leve ou moderada e com normalidade das funções cardíacas e renal. Este trabalho teve como objetivo verificar a qualidade de comprimidos de clortalidona comercializados no município de Sinop/ MT. O controle de qualidade foi realizado como estabelecido na Farmacopeia Brasileira quinta edição (ensaios de identificação, pureza, doseamento, ensaios referentes a forma farmacêutica de comprimidos e perfil de dissolução), de cinco produtos contendo clortalidona 25 mg sendo um produto de medicamento referência, dois de medicamentos genéricos e dois de medicamentos similares. Verificou-se que todos os produtos foram aprovados, cumprindo com todos os requisitos exigidos nos ensaios de qualidade e que estudos referentes ao perfil de dissolução nos lotes de produção de medicamentos são importantes para prever a absorção adequada do princípio ativo

Diuretics are the most used class of drugs that are used to treat hypertension because of their therapeutic efficiency and low cost. This makes a wide variety of medicines commercially available and, linked to this factor, many companies have their batches of medicines suspended due to deviations of quality and modifications made in the formulas after their registration. Chlorthalidone, is a thiazide diuretic drug indicated for treatment of hypertension of patients with mild or moderate hypertension, and with normal cardiac and renal function. This work aimed to assess and compare the quality of medicines containing chlorthalidone commercialized in Sinop-MT. The quality control was performed as established in the fifth edition of the Brazilian Pharmacopoeia (identification, purity and dosage assays, tests referring to the pharmaceutical form of the tablets and their dissolution profile). Among five products containing 25 mg of chlortalidone, one was a reference drug product, two were generic and two were similar drugs. It was found that all products were approved, meeting all the requirements required in the quality tests, and that studies concerning the dissolution profile in batches of drug production are important to predict adequate absorption of the active principle

Hemorrheologic effect of diuretics in the control of blood pressure in the hypertensive patient / Efecto hemorreológico de los diuréticos en el control de la presión arterial en el paciente hipertenso

Background: Diuretics are the first choice as an antihypertensive, because of its efficacy and cost, however its mechanism of action is not well understood. The aim of this work was to analyze the hemorrheological effect of the diuretics as vasodilators in patients with newly diagnosed arterial hypertension. Methods: Patients with hypertension were given diet and exercise recommendations and 25 mg of chlorthalidone per day were prescribed; Hemoglobin/hematocrit, viscosity, and basal nitric oxide (ON) were determined at 15 and 45 days and compared with healthy subjects. Results: We included 28 patients with average age of 48 years old; systolic blood pressure in the treated patients decreased from baseline at 15 days from 130 to 119 mm Hg and at 114 mmHg at 15 to 45 days; diastolic blood pressure decreased from baseline at 15 days from 103 to 97 mm Hg, and at 93 mmHg at 15 to 45 days. The hematocrit increased in both men and women with a statistical significance of the baseline period at 15 days, after that, it remained without significative changes. The viscosity increased similarly to the hematocrit, which conditioned the ON elevation. Conclusions: The increase in hematocrit due to diuretic caused an increase in blood viscosity, which led to an increase in nitric oxide, resulting in lower blood pressure.

Introducción: Los diuréticos son la primera elección como antihipertensivo por su eficacia y costo, sin embargo su mecanismo de acción no está bien esclarecido. El objetivo de este trabajo fue analizar el efecto hemorreológico del diurético como vasodilatador en pacientes con hipertensión arterial de reciente diagnóstico. Métodos: A los pacientes con hipertensión arterial se les dieron recomendaciones de dieta, ejercicio y se prescribió 25 mg de clortalidona al día; se determinaron hemoglobina/hematocrito, viscosidad y óxido nítrico (ON) basal, a los 15 y 45 días y se compararon con sujetos sanos. Resultados: Se incluyeron 28 pacientes, con edad promedio de 48 años; la presión arterial sistólica en los pacientes tratados descendió de la cifra basal a los 15 días de 130 a 119 mmHg, y a 114 mmHg de los 15 a los 45 días; la presión arterial diastólica descendió de la basal a los 15 días de 103 a 97 mmHg, y a 93 mmHg de los 15 a los 45 días . El hematocrito se incrementó en ambos géneros, con significancia estadística del período basal a los 15 días de tratamiento, posteriormente permaneció sin cambios. La viscosidad se incrementó de forma similar al hematocrito, lo que condicionó elevación del ON. Conclusiones: El incremento del hematocrito debido al diurético causó elevación de la viscosidad sanguínea, lo que condujo a incremento del óxido nítrico, repercutiendo en el descenso de la presión arterial.

Effectiveness of Chlorthalidone Plus Amiloride for the Prevention of Hypertension: The PREVER-Prevention Randomized Clinical Trial.

BACKGROUND: Prehypertension is associated with higher cardiovascular risk, target organ damage, and incidence of hypertension. The Prevention of Hypertension in Patients with PreHypertension (PREVER-Prevention) trial aimed to evaluate the efficacy and safety of a low-dose diuretic for the prevention of hypertension and end-organ damage. METHODS AND RESULTS: This randomized, parallel, double-blind, placebo-controlled trial was conducted in 21 Brazilian academic medical centers. Participants with prehypertension who were aged 30 to 70 years and who did not reach optimal blood pressure after 3 months of lifestyle intervention were randomized to a chlorthalidone/amiloride combination pill or placebo and were evaluated every 3 months during 18 months of treatment. The primary outcome was incidence of hypertension. Development or worsening of microalbuminuria, new-onset diabetes mellitus, and reduction of left ventricular mass were secondary outcomes. Participant characteristics were evenly distributed by trial arms. The incidence of hypertension was significantly lower in 372 study participants allocated to diuretics compared with 358 allocated to placebo (hazard ratio 0.56, 95% CI 0.38-0.82), resulting in a cumulative incidence of 11.7% in the diuretic arm versus 19.5% in the placebo arm (P=0.004). Adverse events; levels of blood glucose, glycosylated hemoglobin, creatinine, and microalbuminuria; and incidence of diabetes mellitus were no different between the 2 arms. Left ventricular mass assessed through Sokolow-Lyon voltage and voltage-duration product decreased to a greater extent in participants allocated to diuretic therapy compared with placebo (P=0.02). CONCLUSIONS: A combination of low-dose chlorthalidone and amiloride effectively reduces the risk of incident hypertension and beneficially affects left ventricular mass in patients with prehypertension. CLINICAL TRIAL REGISTRATION: URL: http://www.ClinicalTrials.gov, www.ensaiosclinicos.gov. Unique identifiers: NCT00970931, RBR-74rr6s.

Identification and proportion of the enantiomers of the antihypertensive drug chlortalidone in its Form II by high quality single-crystal X-ray diffraction data.

Chlortalidone (CTD) is a diuretic drug largely used as part of antihypertensive therapies. It is marketed as an equimolar mixture of its enantiomers in the racemic crystal phase named Form I, despite of the higher aqueous solubility of another crystal form. The latter, named Form II, was thought to contain both enantiomers as a racemic conglomerate, i.e., in the form of a mixture of crystals, half of which consists solely of the (R)-enantiomer, the other half the (S)-enantiomer. The occurrence of both enantiomers in individual crystals of CTD Form II was demonstrated in this study. Spontaneous resolution does really occur upon crystallization, as presumed previously even without physical evidence of the (S)-enantiomer. Both (R) and (S)-enantiomers were successfully identified as two domains of a twinned by inversion single crystal of CTD Form II. A reliable Flack parameter of 0.14(4) allowed to determine the proportion of the enantiomers in the crystal, which is formed with 86% of the (R)-enantiomer and 14% of the (S)-enantiomer.

Negative effects of chlorthalidone on sympathetic nervous system and insulin resistance in hypertensive patients may be avoided with spironolactone: further studies are still needed.

Chlorthalidone is commonly used for blood pressure control in hypertensive patients. However, it increases sympathetic nervous system activity and insulin resistance. Both conditions are related with an elevated number of complications and worsen patients' prognosis. Recently has been demonstrated that these adverse effects are avoided with spironolactone administration. Mechanisms to explain increasing sympathetic nervous activity and insulin resistance with chlorthalidone, but not with spironolactone are unclear and under investigation. It should be necessary to continue medical investigation on this field with long-term studies, a larger number of patients and associated comorbidities. The aim should be to establish whether the association of both drugs could be an effective and safety choice to be implemented extensively in clinical practice. That possibility could represent a new alternative for patients' management.

Comparing clinical effectiveness and drug toxicity with hydrochlorothiazide and chlorthalidone using two potency ratios in a managed care population.

This study compared the clinical effectiveness and drug toxicity of chlorthalidone and hydrochlorothiazide. Electronic health records and claims data were used to identify patients initially prescribed chlorthalidone or hydrochlorothiazide. A total of 214 patients prescribed chlorthalidone 25 mg were matched with 428 patients prescribed hydrochlorothiazide 25 mg (1:1 potency ratio) and 214 patients prescribed hydrochlorothiazide 50 mg (1:2 potency ratio). Mean systolic blood pressure/diastolic blood pressure values at least 30 days after initial prescription were lower with chlorthalidone (132.2/74 mm Hg) compared with hydrochlorothiazide 25 mg (137.0/77.5 mm Hg) and hydrochlorothiazide 50 mg (138.6/78.5 mm Hg) (P<.05 for all comparisons). Goal systolic blood pressure/diastolic blood pressure values were achieved in a higher percentage of patients prescribed chlorthalidone (45.0%/78.3%) than with either hydrochlorothiazide 25 mg (32.1%/63.9%) or hydrochlorothiazide 50 mg (32.8%/68.9%) (P<.05 for all comparisons). Mean serum potassium was 3.94 mEq/L with chlorthalidone 25 mg, 4.13 mEq/L with hydrochlorothiazide 25 mg (P<.01 vs chlorthalidone), and 3.96 mEq/L with hydrochlorothiazide 50 mg. These findings indicate that chlorthalidone 25 mg is associated with a better antihypertensive response than hydrochlorothiazide 25 mg or 50 mg, without clinically significant differences in serum potassium.

Phase quantification of antihypertensive drugs - Chlorthalidone, Hydrochlorothiazide, Losartan and combinations, Losartan/Chlorthalidone and Losartan/Hydrochlorothiazide - by the Rietveld method.

The identification and quantification of crystalline phases of antihypertensive drugs - Losartan potassium (LOS-K), Hydrochlorothiazide (HCTZ) and Chlorthalidone (CTD) were carried out by means of X-ray powder diffraction data and the Rietveld method. Quantitative phase analyses of Losartan potassium/Chlorthalidone (LOS-K/CTD) and Losartan potassium/Hydrochlorothiazide (LOS-K/HCTZ) combinations were also evaluated. The results indicated that for diuretics (HCTZ and CTD) only one crystalline phase was found in samples, and for LOS-K the crystal structure showed similarity between the Bragg peaks to the phase described as monoclinic and space group P21/c. After one year storage, the orthorhombic one was also observed in this sample.