Pathophysiology of Antihypertensive Therapy with Diuretics

Covid-19 Vaccine Side Effects and Its Associated Factors Among Healthcare Workers at Dessie Hospital, Ethiopia

Background

Vaccines are a powerful choice to stop disease outbreaks, including covid-19. However, people are hesitant to take vaccinations due to uncertainty about side effects. So, this study aimed to assess covid-19 vaccine side-effect and its associated factors among healthcare workers in Dessie comprehensive specialized hospital, in Ethiopia.

Methods

An institution-based cross-sectional study was conducted at Dessie Comprehensive and Specialized Hospital among 351 vaccinated healthcare workers from April 25 to May 25, 2021. Self-administrated questionnaires were used by consented health workers. Variance inflation factor (VIF) was used to assess the multicollinearity of independent variables. Bivariable and multivariable binary logistic regression were used to identify significant factors of vaccine side effects. The adjusted odds ratio (AOR) with a 95% confidence interval (CI) was reported as the effect size. Statistical significance was considered at p-value <0.05.

Results

Overall, of vaccinated healthcare workers, 56.98% (95% CI, 50.86-61.26%) experienced at least one side effect. The majority of the side effects were fever (44.44%), headache (39.03%), fatigue (27.35%), injection site pain (25.93%), and nausea (24.22%). Healthcare workers with (≥10 years) of work experience (AOR: 3.74, 95% CI, 1.32-10.59), Hesitancy to take the first dose of the Covid-19 vaccine (AOR: 3.01, 95% CI, 1.82-4.99), underlying chronic disease (AOR: 14.41, 95% CI, (5.07-40.92)), being on antihypertensive medication (AOR: 0.15; 95% CI (0.02-0.93)), and unsafe perception of vaccine safety (AOR:3.50; 95% CI, 1.43-8.57) were independent factors of Covax vaccine side effect development.

Conclusion

Overall, common vaccine side effects were identified in healthcare workers who have taken the Covax vaccine. Healthcare workers with (≥10 years) of work experience, Hesitancy to take the first dose, unsafe perception of vaccine safety, and underlined chronic disease were predictors of vaccine side effect occurrence. So, providing vaccine-related information to the community to be vaccinated is mandatory to reduce hesitancy and flaws regarding vaccine safety.

New Strategies for Volume Control in Patients with Diabetes Mellitus, a Narrative Review

Sodium is reabsorbed all along the renal tubules. The positive impacts of sodium-glucose cotransporter-2 inhibitors (SGLT2i), angiotensin receptor neprilysin inhibitor (ARNI) and mineralocorticoid receptor antagonists (MRA) on hard renal and/or cardiac endpoints calls for the role of diuretics in nephroprotection and cardioprotection in patients with diabetes mellitus to be reviewed. Here, we review: (a) the mechanisms of action of the available natriuretics; (b) the physiological adaptations to chronic loop diuretic usage that lead to increased sodium reabsorption in the proximal and distal convoluted tubules; (c) the physiology of sodium retention in patients with diabetes mellitus; and (d) the mechanisms of aldosterone breakthrough. We show the rationale for combined diuretics to target not only the loop of Henle, but also the proximal and distal convoluted tubules. Indeed, higher residual proteinuria in patients treated with renin-angiotensin-aldosterone system (RAAS) blockers portends poorer renal and cardiovascular outcomes. Diuretics are known to optimize the reduction of proteinuria, in addition to RAAS blockers, but may favor aldosterone breakthrough in the absence of MRA. The aim of our study is to support a combined diuretics strategy to improve the management of patients with diabetes mellitus and chronic kidney disease or heart failure.

Epoxy Fatty Acids: From Salt Regulation to Kidney and Cardiovascular Therapeutics: 2019 Lewis K. Dahl Memorial Lecture

Epoxyeicosatrienoic acids (EETs) are epoxy fatty acids that have biological actions that are essential for maintaining water and electrolyte homeostasis. An inability to increase EETs in response to a high-salt diet results in salt-sensitive hypertension. Vasodilation, inhibition of epithelial sodium channel, and inhibition of inflammation are the major EET actions that are beneficial to the heart, resistance arteries, and kidneys. Genetic and pharmacological means to elevate EETs demonstrated antihypertensive, anti-inflammatory, and organ protective actions. Therapeutic approaches to increase EETs were then developed for cardiovascular diseases. sEH (soluble epoxide hydrolase) inhibitors were developed and progressed to clinical trials for hypertension, diabetes mellitus, and other diseases. EET analogs were another therapeutic approach taken and these drugs are entering the early phases of clinical development. Even with the promise for these therapeutic approaches, there are still several challenges, unexplored areas, and opportunities for epoxy fatty acids.

How Do Antihypertensive Drugs Work? Insights from Studies of the Renal Regulation of Arterial Blood Pressure

Though antihypertensive drugs have been in use for many decades, the mechanisms by which they act chronically to reduce blood pressure remain unclear. Over long periods, mean arterial blood pressure must match the perfusion pressure necessary for the kidney to achieve its role in eliminating the daily intake of salt and water. It follows that the kidney is the most likely target for the action of most effective antihypertensive agents used chronically in clinical practice today. Here we review the long-term renal actions of antihypertensive agents in human studies and find three different mechanisms of action for the drugs investigated. (i) Selective vasodilatation of the renal afferent arteriole (prazosin, indoramin, clonidine, moxonidine, α-methyldopa, some Ca(++)-channel blockers, angiotensin-receptor blockers, atenolol, metoprolol, bisoprolol, labetolol, hydrochlorothiazide, and furosemide). (ii) Inhibition of tubular solute reabsorption (propranolol, nadolol, oxprenolol, and indapamide). (iii) A combination of these first two mechanisms (amlodipine, nifedipine and ACE-inhibitors). These findings provide insights into the actions of antihypertensive drugs, and challenge misconceptions about the mechanisms underlying the therapeutic efficacy of many of the agents.

Angiotensin receptor blocker (ARB)-diuretic versus ARB-calcium channel blocker combination therapy for hypertension uncontrolled by ARB monotherapy

Diuretics or calcium channel blockers (CCBs) are used concomitantly with an angiotensin II receptor blocker (ARB). However, it is not established which ARB-based combination therapy is the most effective and safe. This prospective randomized open-label study compared the efficacy and safety of a fixed-dose tablet of losartan (LST)-hydrochlorothiazide (HCTZ) (n = 99) and LST-amlodipine (AML) (n = 77) in Japanese patients whose hypertension was uncontrolled by ARB monotherapy. Blood pressure changed similarly over the 12-month study period. Only LST-HCTZ significantly increased serum uric acid (SUA) in patients with low baseline SUA (<5.6 mg/dL) but not in patients with high baseline SUA.

The target-specific transporter and current status of diuretics as antihypertensive

The currently available diuretics increase the urinary excretion of sodium chloride by selective inhibition of specific sodium transporters in the loop of Henle and distal nephron. In recent years, the molecular cloning of the diuretic-sensitive sodium transporters at distal convoluted tubule has improved our understanding of the cellular mechanisms of action of each class of diuretics. Diuretics are tools of considerable therapeutic importance. First, they effectively reduce blood pressure. Loop and thiazide diuretics are secreted from the proximal tubule via the organic anion transporter-1 and exert their diuretic action by binding to the Na(+)-K(+)-2Cl(-) co-transporter type 2 in the thick ascending limb and the Na(+)-Cl(-) co-transporter in the distal convoluted tubule, respectively. Recent studies in animal models suggest that abundance of these ion transporters is affected by long-term diuretic administration. The WHO/ISH guidelines point out that diuretics enhance the efficacy of antihypertensive drugs and will most often be a component of combination therapy.

Angiotensin receptor blockers shift the circadian rhythm of blood pressure by suppressing tubular sodium reabsorption

Recently, we found that an angiotensin II receptor blocker (ARB) restored the circadian rhythm of the blood pressure (BP) from a nondipper to a dipper pattern, similar to that achieved with sodium intake restriction and diuretics (Fukuda M, Yamanaka T, Mizuno M, Motokawa M, Shirasawa Y, Miyagi S, Nishio T, Yoshida A, Kimura G. J Hypertens 26: 583-588, 2008). ARB enhanced natriuresis during the day, while BP was markedly lower during the night, resulting in the dipper pattern. In the present study, we examined whether the suppression of tubular sodium reabsorption, similar to the action of diuretics, was the mechanism by which ARB normalized the circadian BP rhythm. BP and glomerulotubular balance were compared in 41 patients with chronic kidney disease before and during ARB treatment with olmesartan once a day in the morning for 8 wk. ARB increased natriuresis (sodium excretion rate; U(Na)V) during the day (4.5 ± 2.2 to 5.5 ± 2.1 mmol/h, P = 0.002), while it had no effect during the night (4.3 ± 2.0 to 3.8 ± 1.6 mmol/h, P = 0.1). The night/day ratios of both BP and U(Na)V were decreased. The decrease in the night/day ratio of BP correlated with the increase in the daytime U(Na)V (r = 0.42, P = 0.006). Throughout the whole day, the glomerular filtration rate (P = 0.0006) and tubular sodium reabsorption (P = 0.0005) were both reduced significantly by ARB, although U(Na)V remained constant (107 ± 45 vs. 118 ± 36 mmol/day, P = 0.07). These findings indicate that the suppression of tubular sodium reabsorption, showing a resemblance to the action of diuretics, is the primary mechanism by which ARB can shift the circadian BP rhythm into a dipper pattern.

Urinary albumin excretion during angiotensin II receptor blockade: comparison of combination treatment with a diuretic or a calcium-channel blocker

BACKGROUND

We aimed to test the hypothesis that the angiotensin II receptor blocker (ARB)/diuretic combination decreases the urinary albumin/creatinine ratio (UACR) to a greater extent than treatment with the ARB/calcium-channel blocker (CCB) combination through a mechanism related to a greater reduction of sleep blood pressure (BP).

METHODS

We conducted a prospective, randomized, open-label, blinded end-point trial in hypertensive patients. Patients received olmesartan monotherapy for 12 weeks, followed by an additional use of hydrochlorothiazide (HCTZ) (n = 104) or azelnidipine (n = 103) for 24 weeks after randomization. The measurements of central and ambulatory BP, and laboratory tests were performed at baseline and the end of the study.

RESULTS

The adjusted percent reduction in UACR in the olmesartan/HCTZ group was significantly greater than that in the olmesartan/azelnidipine group (-43.2 vs. -24.0%, P = 0.0014), although the olmesartan/azelnidipine group showed greater decreases in central systolic BP (SBP; P = 0.04), oxidative stress (urinary 8-isoprostane; P = 0.02), inflammation (high-sensitivity C-reactive protein; P = 0.04), and insulin resistance (the homeostasis model assessment insulin resistance index (HOMA(IR)); P < 0.001) than the olmesartan/HCTZ group. In multivariate regression analyses, the significant determinants of change in UACR in the olmesartan/HCTZ group were changes in sleep SBP (P < 0.001), central SBP (P = 0.01), estimated glomerular filtration rate (eGFR) (P = 0.02), and HOMA(IR) (P = 0.03), and those in the olmesartan/azelnidipine group were changes in central SBP (P = 0.001) and urinary 8-isoprostane (P = 0.02).

CONCLUSIONS

These data showed that the ARB/diuretic combination decreased UACR significantly more than the ARB/CCB combination, and this decrease in UACR was associated with a greater magnitude reduction in sleep SBP.

Renoprotective effect of calcium channel blockers in combination with an angiotensin receptor blocker in elderly patients with hypertension. A randomized crossover trial between benidipine and amlodipine

Anti-hypertensive medication with an angiotensin II receptor blocker (ARB) is effective in slowing the progression of chronic kidney disease. The present study was designed to investigate whether calcium channel blockers (CCBs) in combination with an ARB differentially affect kidney function. Elderly hypertensive patients with chronic kidney disease (n = 17, 72 +/- 6 years old) were instructed to self-measure blood pressure. They were randomly assigned to receive either benidipine (4-8 mg/day) or amlodipine (5-10 mg/day) combined with olmesartan (10 mg/day). After 3 months, CCBs were switched in each patient and the same protocol was applied for another 3 months. At baseline, significant correlation was obtained between urine albumin (22.8 +/- 16.7 (median +/- median absolute deviation) mg/g creatinine) and self-measured blood pressure (170 +/- 23/87 +/- 10 (mean +/- SD) mmHg, r = 0.65, p < 0.01). Both regimens reduced blood pressure to a similar extent (139 +/- 22/75 +/- 11 mmHg and 133 +/- 17/72 +/- 10 mmHg, respectively; both p < 0.001), while urine albumin decreased only after combination therapy including benidipine (11.7 +/- 6.1 mg/g creatinine, p < 0.05). Benidipine, but not amlodipine, in combination with olmesartan, reduced urinary albumin excretion in elderly hypertensive patients with chronic kidney disease. The results suggest the importance of selecting medications used in combination with ARB in hypertensive patients with chronic kidney disease.

Clinical effects of torasemide prolonged release in mild-to-moderate hypertension: a randomized noninferiority trial versus torasemide immediate release

The efficacy of a new torasemide prolonged release (PR) formulation to torasemide immediate release (IR) was compared in a randomized noninferiority double-blind trial. Patients with newly diagnosed mild-to-moderate hypertension or unresponsive or poor tolerability to previous antihypertensive monotherapy received 5 mg/day of torasemide-PR (n = 219) or torasemide-IR (n = 223) for 12 weeks (uptitration to 10 mg/day if no response at 4 or 8 weeks). Mean diastolic blood pressure (DBP) reduction in the torasemide-PR group (11.6 +/- 7.1 mmHg, 95% confidence interval [CI] 10.6-12.5) versus torasemide-IR (11.3 +/- 7.5 mmHg, 95% CI 10.2-12.3) met the noninferiority criterion of a nonsided 97.5% CI lower than the preestablished margin of 2 mmHg. A significantly higher percentage of patients in the torasemide-PR group achieved adequate BP control after 8 and 12 weeks. Ambulatory 24-h BP monitoring (ABPM) measurements in a subset of 100 patients showed greater daytime SBP reductions in the torasemide-PR group (128.4 +/- 9.9 mmHg vs. 133.5 +/- 10.4 mmHg, P < 0.05). Safety and tolerability of both formulations were similar.

Efficacy of a very-low-dose combination of perindopril and indapamide--preterax compared with cilazapril monotherapy in patients with inadequate blood pressure control--a randomized, double-blind, add-on study

BACKGROUND

Combined regimen may be superior to monotherapy in blood pressure (BP) control. Since BP control is critically related to cardiovascular mortality and morbidity in hypertensive patients, this study aimed to evaluate the efficacy and safety of a low-dose combined regimen of preterax compared with cilazapril monotherapy for better BP control in treated hypertensive patients.

METHODS

Stable hypertensive patients were evaluated if their systolic BP (SBP) was > 130 mmHg and/or diastolic BP (DBP) was > 85 mmHg even with up to 2 antihypertensive drugs. Patients were excluded if they were on angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers or a diuretic. They were then randomized to receive either preterax (perindopril 2 mg and indapamide 0.625 mg) or cilazapril 2.5 mg once daily in a double-blind fashion for a period of 12 weeks after a 2-week placebo run-in phase. Sitting BP was recorded and the safety and efficacy were evaluated at each visit every 4 weeks. Response was defined as positive if SBP was < or = 140 mmHg and DBP was < or = 90 mmHg at the last visit or there was > 20 mmHg reduction in SBP and/or > 10 mmHg reduction in DBP using either treatment. Plasma biochemical analysis was performed both before and after the treatment.

RESULTS

Among the 47 patients initially enrolled, 41 completed the study (21 in the preterax group, 20 in the cilazapril group). There was no difference in the number of adverse events between the 2 groups. SBP was significantly reduced by preterax (13.43 +/- 12.48mmHg, p < 0.0001) and cilazapril (9.00 +/- 13.75 mmHg, p < 0.05). However, DBP was significantly reduced only by preterax (7.67 +/- 9.40 mmHg, p = 0.0009) but not by cilazapril (3.60 +/- 8.37 mmHg, p > 0.05). The response rate was significantly higher to preterax (100%) than to cilazapril (70%) (p = 0.0086).

CONCLUSION

Though similar in safety, combined regimen preterax was more effective than cilazapril to facilitate adequate BP control in already-treated hypertensives. It can be added on to other antihypertensives for better BP control in clinical hypertension.