Diuretics: a review and update

The Impact of Cardiovascular Drugs in Hyperglycemia and Diabetes: A review of 'Unspoken Side' Effect

AIMS

The increasing prevalence of cardiovascular diseases has led to widespread use of cardiovascular drugs that can adversely impact glucose metabolism. This review focuses on the latest evidence on the potential of cardiovascular drugs to induce adverse glycemic effects but also the underlying mechanisms, prevention, and management strategies.

MATERIALS AND METHODS

A comprehensive literature search was conducted across scientific databases until May 25th, 2024.

RESULTS

Certain cardiovascular drugs can induce hyperglycemia through multiple mechanisms including altered the secretion and sensitivity of insulin through direct cytotoxic effects towards pancreatic beta cells, and increased glucose secretion. Notably, diuretics, beta-blockers, calcium channel blockers, and statins have been associated with significant glycemic disturbances. The risk of hyperglycemia varies based on individual factors, drug dosages, and concurrent medications. These drug-induced hyperglycemic effects may sometimes reverse upon discontinuation of related medication. Effective management should include lifestyle modifications, the use of glucose-lowering medications, and opting for lower-risk cardiovascular drugs. Monitoring for hyperglycemia involves educating affected individuals and conducting regular blood glucose tests. Identifying at-risk individuals and implementing preventive measures are crucial for improving both cardiovascular and metabolic outcomes.

CONCLUSIONS

Certain cardiovascular drugs significantly contribute to hyperglycemia and diabetes mellitus through various mechanisms. Effective management includes identifying at-risk individuals, choosing lower-risk medications, and implementing monitoring and preventive strategies. Further research is needed to fully understand these mechanisms and develop targeted interventions to prevent and manage cardiovascular drug-induced hyperglycemia, thereby improving clinical outcomes.

Diuretic effects of Hecogenin and Hecogenin acetate via aldosterone synthase inhibition

Hecogenin (HEC) is a steroidal saponin found in many plant species and serves as a precursor for steroidal drugs. The diuretic effects of HEC and its derivative, hecogenin acetate (HA), remain largely unexplored. The present study aimed to explore the potential diuretic effects of HEC and HA compared to furosemide (FUR) and spironolactone (SPIR). Additionally, the study aimed to explore the underlying mechanism particularly focusing on aldosterone synthase gene expression. Fifty-four Sprague-Dawley rats were allocated into nine groups (Group 1-9). Group 1 (control) received the vehicle, Groups 2 received FUR 10 mg/kg, Group 3, 4, and 5 were given HEC, while Groups 6, 7 and 8 received HA i.p at doses of 5, 10, and 25 mg/kg, respectively. Group 9 received SPIR i.p at the dose of 25 mg/kg. Urine volume, diuretic index and diuretic activity were monitored at 1, 2, 3, 4, 5, 6, and 24 h post-administration. Treatment was given daily for seven days. After that, rats were sacrificed and blood was collected for serum electrolytes determination. Adrenal glands were dissected out for gene expression studies. The results revealed that HEC and HA at the administered doses significantly and dose-dependently increased urine and electrolyte excretion. These results were primarily observed at 25 mg/kg of each compound. Gene expression studies demonstrated a dose-dependent reduction in aldosterone synthase gene expression, suggesting aldosterone synthesis inhibition as a potential mechanism for their diuretic activity. Notably, HA exhibited more pronounced diuretic effects surpassing those of HEC. This enhanced diuretic activity of HA can be attributed to its stronger impact on aldosterone synthase inhibition. These findings offer valuable insights into the diuretic effects of both HEC and HA along with their underlying molecular mechanisms.

Comparative effectiveness of antihypertensive monotherapies in primary prevention of cardiovascular events-a real-world longitudinal inception cohort study

Introduction

Antihypertensive drugs are used preventatively to lower the risk of cardiovascular disease events. Comparative effectiveness studies on angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), beta-blockers (BBs), calcium channel blockers (CCBs), and thiazides have yielded inconsistent results and given little consideration to patient adherence. Using a longitudinal cohort and considering time-varying adherence and confounding factors, we aimed to estimate the real-world effectiveness of five major antihypertensive drug monotherapies in the primary prevention of cardiovascular events.

Methods

Eligible patients for a retrospective inception cohort study were selected using information obtained from the University of Groningen IADB.nl pharmacy prescription database. Cohort 1 comprised adherent patients with a follow-up time exceeding 1 year, and cohort 2 comprised all patients independent of adherence. The exposures were ACEIs, ARBs, BBs, CCBs, and thiazides. The primary outcome was the time to the first prescription for an acute cardiac drug therapy (CDT) measured using valid drug proxies to identify the first major cardiovascular event. A per-protocol analytical approach was adopted with inverse probability of treatment weighted (IPTW), time-varying Cox regression analysis to obtain the hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

In cohort 1 (n = 22,441), 1,294 patients (5.8%) were prescribed an acute CDT with an average follow-up time of 4.2 ± 2.8 years. Following IPTW, the hazard measures of ARBs and thiazides were lower than those of BBs (HRs: 0.79 and 0.80, respectively; 95% CIs: 0.64-0.97 and 0.69-0.94, respectively). Among drug-treated diabetic patients, the hazard measures were even lower, with HR point estimates of 0.43 (CI: 0.19-0.98) for ARBs and 0.32 (CI: 0.13-0.82) for thiazides. In cohort 2 (n = 33,427) and sensitivity analysis, the comparative effectiveness results for thiazides and BBs were similar to those for cohort 1.

Conclusion

The findings of this real-world analysis suggest that the incidence of CDT associated with long-term thiazide or ARB monotherapy is lower than the incidence of CDT with BBs, notably among high-risk patients. Incidences of CDT associated with ACEIs and CCBs were comparable relative to those associated with BBs.

Diuretic activity of Euphorbia serpens extracts in Wistar rats

Euphorbia serpens has been used in central-west region of Argentina in traditional medicine as diuretic plant. The aim of this present study was to evaluate the diuretic activity of E. serpens in-vivo. We used dried aerial parts, and infusions from these were orally administered to Wistar rats. Its effect was evaluated using furosemide as a positive drug and isotonic salt solution as negative control. Their urine output was quantified at several time intervals. The volume of urine excreted and Na+ increased significantly, being similar to furosemide. Mannitol, was the main component in aqueous extracts of E. serpens, and the acetone extract showed the presence of Δ12- oleanane-type triterpenoids compounds, mainly hederagenin. No toxic effects were observed.

Heterogeneous brain distribution of bumetanide following systemic administration in rats

Bumetanide is used widely as a tool and off-label treatment to inhibit the Na-K-2Cl cotransporter NKCC1 in the brain and thereby to normalize intra-neuronal chloride levels in several brain disorders. However, following systemic administration, bumetanide only poorly penetrates into the brain parenchyma and does not reach levels sufficient to inhibit NKCC1. The low brain penetration is a consequence of both the high ionization rate and plasma protein binding, which restrict brain entry by passive diffusion, and of brain efflux transport. In previous studies, bumetanide was determined in the whole brain or a few brain regions, such as the hippocampus. However, the blood-brain barrier and its efflux transporters are heterogeneous across brain regions, so it cannot be excluded that bumetanide reaches sufficiently high brain levels for NKCC1 inhibition in some discrete brain areas. Here, bumetanide was determined in 14 brain regions following i.v. administration of 10 mg/kg in rats. Because bumetanide is much more rapidly eliminated by rats than humans, its metabolism was reduced by pretreatment with piperonyl butoxide. Significant, up to 5-fold differences in regional bumetanide levels were determined with the highest levels in the midbrain and olfactory bulb and the lowest levels in the striatum and amygdala. Brain:plasma ratios ranged between 0.004 (amygdala) and 0.022 (olfactory bulb). Regional brain levels were significantly correlated with local cerebral blood flow. However, regional bumetanide levels were far below the IC50 (2.4 μM) determined previously for rat NKCC1. Thus, these data further substantiate that the reported effects of bumetanide in rodent models of brain disorders are not related to NKCC1 inhibition in the brain.

Effects of furosemide, acetazolamide and amiloride on renal cortical and medullary tissue oxygenation in non-anaesthetised healthy sheep

It has been proposed that diuretics can improve renal tissue oxygenation through inhibition of tubular sodium reabsorption and reduced metabolic demand. However, the impact of clinically used diuretic drugs on the renal cortical and medullary microcirculation is unclear. Therefore, we examined the effects of three commonly used diuretics, at clinically relevant doses, on renal cortical and medullary perfusion and oxygenation in non-anaesthetised healthy sheep. Merino ewes received acetazolamide (250 mg; n = 9), furosemide (20 mg; n = 10) or amiloride (10 mg; n = 7) intravenously. Systemic and renal haemodynamics, renal cortical and medullary tissue perfusion andP O 2 ${P_{{{\mathrm{O}}_{\mathrm{2}}}}}$ , and renal function were then monitored for up to 8 h post-treatment. The peak diuretic response occurred 2 h (99.4 ± 14.8 mL/h) after acetazolamide, at which stage cortical and medullary tissue perfusion andP O 2 ${P_{{{\mathrm{O}}_{\mathrm{2}}}}}$ were not significantly different from their baseline levels. The peak diuretic response to furosemide occurred at 1 h (196.5 ± 12.3 mL/h) post-treatment but there were no significant changes in cortical and medullary tissue oxygenation during this period. However, cortical tissueP O 2 ${P_{{{\mathrm{O}}_{\mathrm{2}}}}}$ fell from 40.1 ± 3.8 mmHg at baseline to 17.2 ± 4.4 mmHg at 3 h and to 20.5 ± 5.3 mmHg at 6 h after furosemide administration. Amiloride did not produce a diuretic response and was not associated with significant changes in cortical or medullary tissue oxygenation. In conclusion, clinically relevant doses of diuretic agents did not improve regional renal tissue oxygenation in healthy animals during the 8 h experimentation period. On the contrary, rebound renal cortical hypoxia may develop after dissipation of furosemide-induced diuresis.

Bioisoteres for carboxylic acids: From ionized isosteres to novel unionized replacements

Carboxylic acids are key pharmacophoric elements in many molecules. They can be seen as a problem by some, due to perceived permeability challenges, potential for high plasma protein binding and the risk of forming reactive metabolites due to acyl-glucuronidation. By others they are viewed more favorably as they can decrease lipophilicity by adding an ionizable center which can be beneficial for solubility, and can add enthalpic interactions with the target protein. However, there are many instances where the replacement of a carboxylic acid with a bioisosteric group is required. This has led to the development of a number of ionizable groups which sufficiently mimic the carboxylic acid functionality whilst improving, for example, the metabolic profile of the molecule in question. An alternative strategy involves replacement of the carboxylate by neutral functional groups. This review initially details carefully selected examples whereby tetrazoles, acyl sulfonamides or isoxazolols have been beneficially utilized as carboxylic acid bioisosteres altering physicohemical properties, interactions with the target and metabolism and/or pharmacokinetics, before delving further into the binding mode of carboxylic acid derivatives with their target proteins. This analysis highlights new ways to consider the replacement of carboxylic acids by neutral bioisosteric groups which either rely on hydrogen bonds or cation-π interactions. It should serve as a useful guide for scientists working in drug discovery.

Phototoxic Reactions Inducted by Hydrochlorothiazide and Furosemide in Normal Skin Cells-In Vitro Studies on Melanocytes and Fibroblasts

Hypertension is known to be a multifactorial disease associated with abnormalities in neuroendocrine, metabolic, and hemodynamic systems. Poorly controlled hypertension causes more than one in eight premature deaths worldwide. Hydrochlorothiazide (HCT) and furosemide (FUR), being first-line drugs in the treatment of hypertension, are among others the most frequently prescribed drugs in the world. Currently, many pharmacoepidemiological data associate the use of these diuretics with an increased risk of adverse phototoxic reactions that may induce the development of melanoma and non-melanoma skin cancers. In this study, the cytotoxic and phototoxic potential of HCT and FUR against skin cells varied by melanin pigment content was assessed for the first time. The results showed that both drugs reduced the number of metabolically active normal skin cells in a dose-dependent manner. UVA irradiation significantly increased the cytotoxicity of HCT towards fibroblasts by approximately 40% and melanocytes by almost 20% compared to unirradiated cells. In the case of skin cells exposed to FUR and UVA radiation, an increase in cytotoxicity by approximately 30% for fibroblasts and 10% for melanocytes was observed. Simultaneous exposure of melanocytes and fibroblasts to HCT or FUR and UVAR caused a decrease in cell viability, and number, which was confirmed by microscopic assessment of morphology. The phototoxic effect of HCT and FUR was associated with the disturbance of redox homeostasis confirming the oxidative stress as a mechanism of phototoxic reaction. UVA-irradiated drugs increased the generation of ROS by 10-150%, and oxidized intracellular thiols. A reduction in mitochondrial potential of almost 80% in melanocytes exposed to HCT and UVAR and 60% in fibroblasts was found due to oxidative stress occurrence. In addition, HCT and FUR have been shown to disrupt the cell cycle of normal skin cells. Finally, it can be concluded that HCT is the drug with a stronger phototoxic effect, and fibroblasts turn out to be more sensitive cells to the phototoxic effect of tested drugs.

Diuretic resistance and the role of albumin in congestive heart failure

Diuresis with loop diuretics is the mainstay treatment for volume optimization in patients with congestive heart failure, in which perfusion and volume expansion play a crucial role. There are robust guidelines with extensive evidence for the management of heart failure; however, clear guidance is needed for patients who do not respond to standard diuretic treatment. Diuretic resistance (DR) can be defined as an insufficient quantity of natriuresis with proper diuretic therapy. A combination of diuretic regimens is used to overcome DR and, more recently, SGLT2 inhibitors have been shown to improve diuresis. Despite DR being relatively common, it is challenging to treat and there remains a notable lack of substantial data guiding its management. Moreover, DR has been linked with poor prognosis. This review aims to expose the multiple approaches for treatment of patients with DR and the importance of intravascular volume expansion in the response to therapy.

Renal calcification in children with renal tubular acidosis: What a paediatrician ‎should ‎know‎

Renal tubular acidosis (RTA) can lead to renal calcification in children, which can cause various complications and impair renal function. This review provides pediatricians with a comprehensive understanding of the relationship between RTA and renal calcification, highlighting essential aspects for clinical management. The article analyzed relevant studies to explore the prevalence, risk factors, underlying mechanisms, and clinical implications of renal calcification in children with RTA. Results show that distal RTA (type 1) is particularly associated with nephrocalcinosis, which presents a higher risk of renal calcification. However, there are limitations to the existing literature, including a small number of studies, heterogeneity in methodologies, and potential publication bias. Longitudinal data and control groups are also lacking, which limits our understanding of long-term outcomes and optimal management strategies for children with RTA and renal calcification. Pediatricians play a crucial role in the early diagnosis and management of RTA to mitigate the risk of renal calcification and associated complications. In addition, alkaline therapy remains a cornerstone in the treatment of RTA, aimed at correcting the acid-base imbalance and reducing the formation of kidney stones. Therefore, early diagnosis and appropriate therapeutic interventions are paramount in preventing and managing renal calcification to preserve renal function and improve long-term outcomes for affected children. Further research with larger sample sizes and rigorous methodologies is needed to optimize the clinical approach to renal calcification in the context of RTA in the pediatric population.

Therapeutic management of congenital forms of endocrine hypertension

Congenital forms of endocrine hypertension are rare and potentially life-threatening disorders, primarily caused by genetic defects affecting adrenal steroid synthesis and activation pathways. These conditions exhibit diverse clinical manifestations, which can be distinguished by their unique molecular mechanisms and steroid profiles. Timely diagnosis and customized management approach are crucial to mitigate unfavorable outcomes associated with uncontrolled hypertension and other related conditions. Treatment options for these disorders depend on the distinct underlying pathophysiology, which involves specific pharmacological therapies or surgical adrenalectomy in some instances. This review article summarizes the current state of knowledge on the therapeutic management of congenital forms of endocrine hypertension, focusing on familial hyperaldosteronism (FH), congenital adrenal hyperplasia, apparent mineralocorticoid excess, and Liddle syndrome. We provide an overview of the genetic and molecular pathogenesis underlying each disorder, describe the clinical features, and discuss the various therapeutic approaches available and their risk of adverse effects, aiming to improve outcomes in patients with these rare and complex conditions.

Sex Differences in the Preventive Effect of Cardiovascular and Metabolic Therapeutics on Dementia

Dementia is a clinical syndrome characterized by progressive impairment of cognitive and functional abilities. As currently applied treatments for dementia can only delay the progression of dementia and cannot fundamentally cure it, much attention is being paid to reducing its incidence by preventing the associated risk factors. Cardiovascular and metabolic diseases are well-known risk factors for dementia, and many studies have attempted to prevent dementia by treating these risk factors. Growing evidence suggests that sex-based factors may play an important role in the pathogenesis of dementia. Therefore, a deeper understanding of the differences in the effects of drugs based on sex may help improve their effectiveness. In this study, we reviewed sex differences in the impact of therapeutics targeting risk factors for dementia, such as cardiovascular and metabolic diseases, to prevent the incidence and/or progression of dementia.

Concurrent exercise training induces additional benefits to hydrochlorothiazide: Evidence for an improvement of autonomic control and oxidative stress in a model of hypertension and postmenopause

OBJECTIVE

This study aimed to evaluate whether exercise training could contribute to a better modulation of the neurohumoral mechanisms linked to the pathophysiology of arterial hypertension (AH) in postmenopausal hypertensive rats treated with hydrochlorothiazide (HCTZ).

METHODS

Female spontaneously hypertensive rats (SHR) (150-200g, 90 days old) were distributed into 5 hypertensive groups (n = 7-8 rats/group): control (C), ovariectomized (O), ovariectomized treated with HCTZ (OH), ovariectomized submitted to exercise training (OT) and ovariectomized submitted to exercise training and treated with HCTZ (OTH). Ovarian hormone deprivation was performed through bilateral ovariectomy. HCTZ (30mg/kg/day) and concurrent exercise training (3d/wk) were conducted lasted 8 weeks. Arterial pressure (AP) was directly recorded. Cardiac effort was evaluated using the rate-pressure product (RPP = systolic AP x heart rate). Vasopressin V1 receptor antagonist, losartan and hexamethonium were sequentially injected to evaluate the vasopressor systems. Inflammation and oxidative stress were evaluated in cardiac tissue.

RESULTS

In addition to the reduction in AP, trained groups improved RPP, AP variability, bradycardic (OT: -1.3 ± 0.4 and OTH: -1.6 ± 0.3 vs. O: -0.6 ± 0.3 bpm/mmHg) and tachycardic responses of baroreflex sensitivity (OT: -2.4 ± 0.8 and OTH: -2.4 ± 0.8 vs. O: -1.3 ± 0.5 bpm/mmHg), NADPH oxidase and IL-10/TNF-α ratio. Hexamethonium injection revealed reduced sympathetic contribution on basal AP in OTH group (OTH: -49.8 ± 12.4 vs. O: -74.6 ± 18.1 mmHg). Furthermore, cardiac sympathovagal balance (LF/HF ratio), IL-10 and antioxidant enzymes were enhanced in OTH group. AP variability and baroreflex sensitivity were correlated with systolic AP, RPP, LF/HF ratio and inflammatory and oxidative stress parameters.

CONCLUSION

The combination of HCTZ plus concurrent exercise training induced additional positive adaptations in cardiovascular autonomic control, inflammation and redox balance in ovariectomized SHR. Therefore, combining exercise and medication may represent a promising strategy for managing classic and remaining cardiovascular risks in AH.

The loop diuretic torasemide but not azosemide potentiates the anti-seizure and disease-modifying effects of midazolam in a rat model of birth asphyxia

Loop diuretics such as furosemide and bumetanide, which act by inhibiting the Na-K-2Cl cotransporter NKCC2 at the thick ascending limb of the loop of Henle, have been shown to exert anti-seizure effects. However, the exact mechanism of this effect is not known. For bumetanide, it has been suggested that inhibition of the NKCC isoform NKCC1 in the membrane of brain neurons may be involved; however, NKCC1 is expressed by virtually all cell types in the brain, which makes any specific targeting of neuronal NKCC1 by bumetanide impossible. In addition, bumetanide only poorly penetrates the brain. We have previously shown that loop diuretics azosemide and torasemide also potently inhibit NKCC1. In contrast to bumetanide and furosemide, azosemide and torasemide lack a carboxylic group, which should allow them to better penetrate through biomembranes by passive diffusion. Because of the urgent medical need to develop new treatments for neonatal seizures and their adverse outcome, we evaluated the effects of azosemide and torasemide, administered alone or in combination with phenobarbital or midazolam, in a rat model of birth asphyxia and neonatal seizures. Neither diuretic suppressed the seizures when administered alone but torasemide potentiated the anti-seizure effect of midazolam. Brain levels of torasemide were below those needed to inhibit NKCC1. In addition to suppressing seizures, the combination of torasemide and midazolam, but not midazolam alone, prevented the cognitive impairment of the post-asphyxial rats at 3 months after asphyxia. Furthermore, aberrant mossy fiber sprouting in the hippocampus was more effectively prevented by the combination. We assume that either an effect on NKCC1 at the blood-brain barrier and/or cells in the periphery or the NKCC2-mediated diuretic effect of torasemide are involved in the present findings. Our data suggest that torasemide may be a useful option for improving the treatment of neonatal seizures and their adverse outcome.

Potential Pharmacokinetic Interactions of Common Cardiovascular Drugs and Selected European and Latin American Herbal Medicines: A Scoping Review

BACKGROUND

Herb-drug interactions are nowadays an important decision factor in many healthcare interventions. Patients with cardiovascular risk factors such as hyperlipidemia and hypertension are usually prescribed long-term treatments. We need more informed decision tools to direct future clinical research and decision making to avoid HDI occurrences in this group.

METHODS

A scoping review was conducted using data from online databases such as PUBMED, the National Library of Medicine, and the electronic Medicines Compendium. Included studies consisted of the reported effects on Phase 1/2 and P-glycoprotein of herbal medicines listed in the medicines agencies of Latin America and Europe and drugs used for cardiovascular conditions (statins, diuretics, beta blockers, calcium channel blockers, and ACE inhibitors). The cross tabulation of the results allowed for finding potential HDI.

RESULTS AND CONCLUSIONS

as per the preclinical data reviewed here, we encourage more clinical research on whether drugs with apparently very low interaction risk, such as pravastatin, nadolol, and nimodipine/nitrendipine, may help prevent HDI when statins, beta blockers, and calcium channel blockers, respectively, are prescribed for long-term treatments.

Impact of Albumin Binding Function on Pharmacokinetics and Pharmacodynamics of Furosemide

Background and Objectives: Albumin binding of the loop diuretic furosemide forms the basis for its transport to the kidney and subsequent tubular secretion, which is a prerequisite for its therapeutic effects. Accordingly, high albumin concentrations should result in higher efficacy of furosemide. However, study results on the combination of furosemide in conjunction with albumin, and on the efficacy of furosemide in hypoalbuminemia, did not confirm this hypothesis. The aim of this study was to determine the efficacy of furosemide not only in relation to albumin concentration, but also taking albumin function into account. Materials and Methods: In a prospective and non-interventional clinical observational trial, blood and urine samples from 50 intensive care patients receiving continuous intravenous furosemide therapy were evaluated. Albumin binding capacity (ABiC) determination allowed conclusions to be drawn about the binding site-specific loading state of albumin, by quantifying the unbound fraction of the fluorescent marker dansylsarcosine. In addition, assessment of the total concentration of furosemide in plasma and urine, as well as the concentration of free furosemide fraction in plasma, was performed by HPLC−MS. The efficacy of furosemide was evaluated by the ratio of urine excretion to fluid intake. Results: In patients with an ABiC ≥ 60% free furosemide fraction was significantly lower compared to patients with a lower ABiC (p < 0.001), urinary furosemide concentration was higher (p = 0.136), and a significantly higher proportion of infused furosemide was excreted renally (p = 0.010). ABiC was positively correlated (r = 0.908, p = 0.017) with increase in the urine excretion to fluid input ratio after initiation of furosemide therapy. Conclusions: ABiC could serve as a marker for individual response to furosemide and could be used to generate patient-specific therapeutic regimens. In view of the relatively low number of patients in this study, the relationship between furosemide efficacy and albumin function should be investigated in larger studies in the future.

Long-term Survival Rate Following Myocardial Infarction and the Effect of Discharge Medications on the Survival Rate

BACKGROUND

The evaluation of the risk factors associated with the long-term survival rate of patients with myocardial infarction (MI) and the effects of discharge medications can significantly help select the most effective strategies for improving treatment.

STUDY DESIGN

A retrospective cohort study.

METHODS

The participants of this retrospective cohort study were 21,181 patients who suffered from MI and were hospitalized in the cardiac care unit (CCU) of different public, private, and military hospitals in Iran from 20 March 2013 to 20 March 2014. Participants were followed up until February 2020 for any cardiovascular disease (CVD) mortality. To evaluate survival rate, the differences between groups, and the factors related to MI death, Kaplan-Meier, log-rank test, and Cox proportional-hazards model were used, respectively.

RESULTS

One, three, five, and seven-year survival rates of patients were 88%, 81%, 78%, and 74%, respectively. Regarding the interaction effect of prescribed medical drugs, the highest 7-year survival rate of 86% (95% CI: 72%, 93%) was related to people who consumed anticoagulants, aspirin, clopidogrel, beta blockers, angiotensin-converting enzymes (ACEs), and angiotensin II receptor antagonist simultaneously. Considering the effect of other variables, the consumption of anticoagulants was associated with a decrease in survival rate (HR=1.13 CI: 1.06, 1.19).

CONCLUSION

As evidenced by the results of this study, different combinations of prescribed medication drugs had protective effects on long-term mortality compared to the group without any drug. Nonetheless, according to the drugs in each combination therapy, this protective effect ranged from HR=0.27 to HR=0.89. It is recommended that further studies compare the long-term effects of different drug combinations and also consider adherence to treatment in evaluating the effects of these combinations.

Mitochondrial Effects of Common Cardiovascular Medications: The Good, the Bad and the Mixed

Mitochondria are central organelles in the homeostasis of the cardiovascular system via the integration of several physiological processes, such as ATP generation via oxidative phosphorylation, synthesis/exchange of metabolites, calcium sequestration, reactive oxygen species (ROS) production/buffering and control of cellular survival/death. Mitochondrial impairment has been widely recognized as a central pathomechanism of almost all cardiovascular diseases, rendering these organelles important therapeutic targets. Mitochondrial dysfunction has been reported to occur in the setting of drug-induced toxicity in several tissues and organs, including the heart. Members of the drug classes currently used in the therapeutics of cardiovascular pathologies have been reported to both support and undermine mitochondrial function. For the latter case, mitochondrial toxicity is the consequence of drug interference (direct or off-target effects) with mitochondrial respiration/energy conversion, DNA replication, ROS production and detoxification, cell death signaling and mitochondrial dynamics. The present narrative review aims to summarize the beneficial and deleterious mitochondrial effects of common cardiovascular medications as described in various experimental models and identify those for which evidence for both types of effects is available in the literature.

Cardiorenal Interactions: A Review

A complex interaction occurs between cardiac and renal function. They are intricately tied together, and a range of disorders in both the heart and kidneys can alter the function of the other. The pathophysiology is complex, and these conditions are termed cardiorenal syndromes. They can be acute and/or chronic in nature, they result in and from hemodynamic consequences, systemic congestion, and metabolic abnormalities, and they lead to dysfunction of both the heart and kidneys. The aim of this article is to provide a review for cardiologists and intensivists who are treating patients for whom cardiac and renal interactions may complicate their picture. We review acute kidney injuries, management of the complications of renal dysfunction, renal replacement therapy, and cardiorenal syndromes.

Revisiting diuretic choice in chronic kidney disease

PURPOSE OF REVIEW

Existing guidelines offer little direction about the use of thiazide and loop diuretics in patients with chronic kidney disease (CKD). This review summarizes recent studies impacting indications and safety considerations for these agents in patients with CKD.

RECENT FINDINGS

Chlorthalidone reduces blood pressure compared to placebo in patients with advanced CKD, challenging the belief that thiazide diuretics lose efficacy at lower glomerular filtration rates (GFR). Existing studies show no clear impact of thiazide or loop diuretic use on kidney or cardiovascular outcomes in patients with CKD. Sodium-glucose co-transporter type 2 (SGLT2) inhibitors have diuretic effects, but concomitant use of a diuretic does not diminish the preventive benefits of these agents against acute kidney injury (AKI). Despite theoretical concerns, thiazide diuretics likely do not worsen circulating vasopressin levels or cyst progression in polycystic kidney disease and may be useful for alleviating polyuria from tolvaptan. Diuretics cause multiple adverse effects, including electrolyte abnormalities, hemodynamic-mediated decrease in estimated GFR, and AKI.

SUMMARY

Recent evidence supports expanded indications for diuretics in patients with kidney disease, including chlorthalidone for hypertension in advanced CKD. Monitoring electrolytes and estimated GFR is critical to ensure patient safety when prescribing these agents for patients with CKD.

Alleviation of liver cirrhosis and associated portal-hypertension by Astragalus species in relation to their UPLC-MS/MS metabolic profiles: a mechanistic study

Liver cirrhosis is a late-stage liver disease characterized by excessive fibrous deposition triggering portal-hypertension (PH); the prime restrainer for cirrhosis-related complications. Remedies that can dually oppose hepatic fibrosis and lower PH, may prevent progression into decompensated-cirrhosis. Different Astragalus-species members have shown antifibrotic and diuretic actions with possible subsequent PH reduction. However, A.spinosus and A.trigonus were poorly tested for eliciting these actions. Herein, A.spinosus and A.trigonus roots and aerial parts extracts were subjected to comprehensive metabolic-fingerprinting using UHPLC-MS/MS resulting in 56 identified phytoconstituents, followed by chemometric untargeted analysis that revealed variable metabolic profiles exemplified by different species and organ types. Consequently, tested extracts were in-vivo evaluated for potential antifibrotic/anticirrhotic activity by assessing specific markers. The mechanistic prospective to induce diuresis was investigated by analyzing plasma aldosterone and renal-transporters gene-expression. Serum apelin and dimethylarginine-dimethylaminohydrolase-1 were measured to indicate the overall effect on PH. All extracts amended cirrhosis and PH to varying extents and induced diuresis via different mechanisms. Further, An OPLS model was built to generate a comprehensive metabolic-profiling of A.spinosus and A.trigonus secondary-metabolites providing a chemical-based evidence for their efficacious consistency. In conclusion, A.spinosus and A.trigonus organs comprised myriad pharmacologically-active constituents that act synergistically to ameliorate cirrhosis and associated PH.

Chronic obstructive pulmonary disease and atherosclerosis: common mechanisms and novel therapeutics

Chronic obstructive pulmonary disease (COPD) and atherosclerosis are chronic irreversible diseases, that share a number of common causative factors including cigarette smoking. Atherosclerosis drastically impairs blood flow and oxygen availability to tissues, leading to life-threatening outcomes including myocardial infarction (MI) and stroke. Patients with COPD are most likely to die as a result of a cardiovascular event, with 30% of all COPD-related deaths being attributed to cardiovascular disease (CVD). Both atherosclerosis and COPD involve significant local (i.e. lung, vasculature) and systemic inflammation and oxidative stress, of which current pharmacological treatments have limited efficacy, hence the urgency for the development of novel life-saving therapeutics. Currently these diseases must be treated individually, with no therapies available that can effectively reduce the likelihood of comorbid CVD other than cessation of cigarette smoking. In this review, the important mechanisms that drive atherosclerosis and CVD in people with COPD are explained and we propose that modulation of both the oxidative stress and the inflammatory burden will provide a novel therapeutic strategy to treat both the pulmonary and systemic manifestations related to these diseases.

Furosemide-induced systemic dehydration alters the proteome of rabbit vocal folds

Whole-body dehydration (i.e., systemic dehydration) leads to vocal fold tissue dehydration. Furosemide, a common diuretic prescribed to treat hypertension and edema-associated conditions, induces systemic dehydration. Furosemide also causes voice changes in human speakers, making this method of systemic dehydration particularly interesting for vocal fold dehydration studies. Our objective was to obtain a comprehensive proteome of vocal folds following furosemide-induced systemic dehydration. New Zealand White rabbits were used as the animal model and randomly assigned to euhydrated (control) or furosemide-dehydrated groups. Systemic dehydration, induced by injectable furosemide, was verified by an average body weight loss of -5.5% and significant percentage changes in blood analytes in the dehydrated rabbits compared to controls. Vocal fold specimens, including mucosa and muscle, were processed for proteomic analysis using label-free quantitation LC-MS/MS. Over 1600 proteins were successfully identified across all vocal fold samples; and associated with a variety of cellular components and ubiquitous cell functions. Protein levels were compared between groups showing 32 proteins differentially regulated (p ≤ 0.05) in the dehydrated vocal folds. These are mainly involved with mitochondrial translation and metabolism. The downregulation of proteins involved in mitochondrial metabolism in the vocal folds suggests a mechanism to prevent oxidative stress associated with systemic dehydration. SIGNIFICANCE: Voice disorders affect different population demographics worldwide with one in 13 adults in the United States reporting voice problems annually. Vocal fold systemic hydration is clinically recognized for preventing and treating voice problems and depends on optimal body hydration primarily achieved by water intake. Herein, we use the rabbit as a translatable animal model, and furosemide as a translatable method of systemic dehydration, to reveal a comprehensive proteomic profile of vocal fold mucosa and muscle in response to systemic dehydration. The significant subset of proteins differentially regulated due to furosemide-induced dehydration offer novel insights into the molecular mechanisms of systemic dehydration in the vocal folds. These findings also deepen our understanding of changes to tissue biology after diuretic administration.

Thiazide and thiazide-like diuretics: how to make the right choice?

Most patients with arterial hypertension (AH) require a combination treatment to achieve the goal blood pressure. According to Russian and international clinical guidelines on the treatment of AH patients, various antihypertensive drugs may be combined; however, not all combinations have similar profiles of safety and clinical efficacy. In this respect, special attention is given to combinations of renin-angiotensin-aldosterone system inhibitors and thiazide (hydrochlorothiazide) or thiazide-like (chlortalidone, indapamide) diuretics. Diuretics also differ in their mechanisms of action, presence of pleiotropic effects and organ-protective properties, effects on the prognosis, and in the evidence base. This review discusses the place of thiazide and thiazide-like diuretics in the treatment of patients with AH and provides an evaluation of major differences in pharmacological and clinical effects of drugs of the diuretic class.

Current and Emerging Classes of Pharmacological Agents for the Management of Hypertension

Cardiovascular disease accounts for more than 17 million deaths globally every year, of which complications of hypertension account for 9.4 million deaths worldwide. Early detection and management of hypertension can prevent costly interventions, including dialysis and cardiac surgery. Non-pharmacological approaches for managing hypertension commonly involve lifestyle modification, including exercise and dietary regulations such as reducing salt and fluid intake; however, a majority of patients will eventually require antihypertensive medications. In 2020, the International Society of Hypertension published worldwide guidelines in its efforts to reduce the global prevalence of raised blood pressure (BP) in adults aged 18 years or over. Currently, several classes of medications are used to control hypertension, either as mono- or combination therapy depending on the disease severity. These drug classes include those that target the renin-angiotensin-aldosterone system (RAAS) and adrenergic receptors, calcium channel blockers, diuretics and vasodilators. While some of these classes of medications have shown significant benefits in controlling BP and reducing cardiovascular mortality, the prevalence of hypertension remains high. Significant efforts have been made in developing new classes of drugs that lower BP; these medications exert their therapeutic benefits through different pathways and mechanism of actions. With several of these emerging classes in phase III clinical trials, it is hoped that the discovery of these novel therapeutic avenues will aid in reducing the global burden of hypertension.

CNS pharmacology of NKCC1 inhibitors

The Na-K-2Cl cotransporter NKCC1 and the neuron-specific K-Cl cotransporter KCC2 are considered attractive CNS drug targets because altered neuronal chloride regulation and consequent effects on GABAergic signaling have been implicated in numerous CNS disorders. While KCC2 modulators are not yet clinically available, the loop diuretic bumetanide has been used off-label in attempts to treat brain disorders and as a tool for NKCC1 inhibition in preclinical models. Bumetanide is known to have anticonvulsant and neuroprotective effects under some pathophysiological conditions. However, as shown in several species from neonates to adults (mice, rats, dogs, and by extrapolation in humans), at the low clinical doses of bumetanide approved for diuresis, this drug has negligible access into the CNS, reaching levels that are much lower than what is needed to inhibit NKCC1 in cells within the brain parenchyma. Several drug discovery strategies have been initiated over the last ∼15 years to develop brain-permeant compounds that, ideally, should be selective for NKCC1 to eliminate the diuresis mediated by inhibition of renal NKCC2. The strategies employed to improve the pharmacokinetic and pharmacodynamic properties of NKCC1 blockers include evaluation of other clinically approved loop diuretics; development of lipophilic prodrugs of bumetanide; development of side-chain derivatives of bumetanide; and unbiased high-throughput screening approaches of drug discovery based on large chemical compound libraries. The main outcomes are that (1), non-acidic loop diuretics such as azosemide and torasemide may have advantages as NKCC1 inhibitors vs. bumetanide; (2), bumetanide prodrugs lead to significantly higher brain levels than the parent drug and have lower diuretic activity; (3), the novel bumetanide side-chain derivatives do not exhibit any functionally relevant improvement of CNS accessibility or NKCC1 selectivity vs. bumetanide; (4) novel compounds discovered by high-throughput screening may resolve some of the inherent problems of bumetanide, but as yet this has not been achieved. Thus, further research is needed to optimize the design of brain-permeant NKCC1 inhibitors. In parallel, a major challenge is to identify the mechanisms whereby various NKCC1-expressing cellular targets of these drugs within (e.g., neurons, oligodendrocytes or astrocytes) and outside the brain parenchyma (e.g., the blood-brain barrier, the choroid plexus, and the endocrine system), as well as molecular off-target effects, might contribute to their reported therapeutic and adverse effects.

Safety of torasemide in healthy adult dogs administered daily for 26 weeks

Thirty‐two (16 males and 16 females) healthy young beagles were randomly divided into four groups of eight. The control group remained untreated. Torasemide (ISEMID^®, Ceva Santé Animale) was orally administered, once daily, at 0.5 mg/kg from Days 1–5 then 0.25 mg/kg to Day 182, and at three times and five times this dosing regimen in two additional groups. Treated animals (predominantly at the higher dose levels) showed dryness of the oral mucosa, evidence of diuresis, decreased diet consumption, decreased bodyweight gain over the first 3 weeks, increased water consumption, increases in erythrocytes count, haemoglobin, calcium and magnesium, decrease in chloride, phosphorus, potassium and sodium, increases in urine pH, decreases in urine specific gravity and increases in serum aldosterone concentrations. Plasma concentrations of torasemide increased in a dose‐dependent manner and showed no evidence of accumulation. There were also changes to electrocardiogram patterns and the macroscopic and microscopic appearance of the kidney and adrenal glands, but these changes were almost exclusively confined to the over‐dosed groups. In conclusion, torasemide was found to be safe when administered to dogs at 0.25 mg/kg once daily for 26 weeks, and any changes were consistent with its known diuretic effects.

Inpatient Diuretic Management of Acute Heart Failure: A Practical Review

The inpatient treatment of acute heart failure (AHF) is aimed at achieving euvolemia, relieving symptoms, and reducing rehospitalization. Adequate treatment of AHF is rooted in understanding the pharmacokinetics and pharmacodynamics of select diuretic agents used to achieve decongestion. While loop diuretics remain the primary treatment of AHF, the dosing strategies of loop diuretics and the use of adjunct diuretic classes to augment clinical response can be complex. This review examines the latest strategies for diuretic management in patients with AHF, including dosing and monitoring strategies, interaction of diuretics with other medication classes, use adjunctive therapies, and assessing endpoints for diuretic. The goal of the review is to guide the reader through commonly encountered clinical scenarios and pitfalls in the diuretic management of patients with AHF.

Evaluation of urine electrolytes for the diagnosis of hypoadrenocorticism in dogs

BACKGROUND

Most dogs with primary hypoadrenocorticism (HA) have a mineralocorticoid deficiency, which decreases renal tubular sodium reabsorption and potassium excretion. Limited information is available concerning the clinical value of measuring urine electrolytes to aid in an HA diagnosis.

OBJECTIVES

We aimed to evaluate the diagnostic utility of urine electrolyte measurements in dogs with HA.

METHODS

Urine sodium and potassium concentrations were measured in 89 dogs, including 39 dogs with HA and 50 controls with nonadrenal illness. Fractional excretions of sodium (FE_Na ) and potassium (FE_K ) were also calculated. Urine electrolytes and fractional excretion values were compared between the groups. Sensitivities and specificities were determined for various cut-points.

RESULTS

The median urine sodium to potassium (Na:K) ratio was twofold greater (P < .001), and median FE_Na was fourfold greater (P < .001) in HA dogs as compared with controls. However, no cut-point for any variable with >90% sensitivity or specificity provided a corresponding specificity or sensitivity of >50%. When only dogs with abnormal serum or plasma electrolytes were included in the analyses, absolute urine electrolyte concentrations and FE_Na were not different between study populations (P > .05 for all comparisons), but the FE_K was increased (P = .005) and the urine potassium:creatinine ratio was decreased (P < .001) in the control dogs compared with the dogs with HA.

CONCLUSIONS

Urine electrolyte concentrations and fractional excretions are altered in dogs with HA. However, substantial overlap exists with control dogs with nonadrenal illness. Therefore, these values are unlikely to have diagnostic utility for dogs with HA.

A Comparative Study of Safety Outcomes of Sodium Glucose Cotransporter-2 Inhibitors and Loop Diuretics Among Diabetic Patients Using Real-world Data

Sodium glucose cotransporter-2 (SGLT2) inhibitors and loop diuretics can cause volume depletion. However, the long-term safety of the concurrent use of both agents has not been widely evaluated. We conducted a retrospective observational cohort study to evaluate the safety of SGLT2 inhibitors with loop diuretics vs SGLT2 inhibitors alone among diabetic patients. The primary endpoint was a composite of volume-depletion adverse events at 1 month and 12 months. Of the 400 patients included, 98 received SGLT2 inhibitors with a loop diuretic and 302 received SGLT2 inhibitors alone. The concurrent use of SGLT2 inhibitors and loop diuretics was tolerated at 1 month; however, it resulted in a significant increase in volume-depletion events at 12 months (10.2% vs 1.7%; aHR = 7.03, 95% CI (1.80-27.37), P-value = 0.005). In conclusion, the long-term concurrent use of SGLT2 inhibitors and loop diuretics increases the risk of volume depletion, warranting frequent monitoring.

Simultaneous determination of five diuretic drugs using quantitative analysis of multiple components by a single marker

BACKGROUND

Loop diuretics are commonly used in clinical practice to manage high fluid loads and to control fluid balance. In this paper, a novel quantitative analysis method for multiple components with a single marker (QAMS) was developed for the simultaneous determination of 5 diuretic drugs furosemide, torasemide, azosemide, etacrynic acid, and bumetanide, by HPLC. Qualitative analysis was performed using relative retention time and ultraviolet (UV) spectral similarity as the double indicator. The QAMS method was conducted with etacrynic acid as an internal reference substance. The quantities of the other four diuretics were calculated by using the relative correction factors for etacrynic acid. The quantities of the 5 diuretic drugs were also determined by the external standard method (ESM). Chromatographic separation was achieved on a Shimadzu HC-C₁₈ column (150 mm × 4.6 mm, 5 µm) using 50 mM potassium dihydrogen phosphate (pH adjusted to 4.0 with phosphoric acid) with acetonitrile (64:36, v/v) as the mobile phase at a flow rate of 1.0 mL/min and a column temperature of 30 ℃.

RESULTS

Under these conditions, the 5 diuretic drugs were well separated, showing linear relationships within certain ranges. The quantitative results showed that there was no significant difference between the QAMS and ESM methods.

CONCLUSIONS

Overall, the HPLC-QAMS analytical scheme established in this study is a simple, efficient, economical, and accurate method for the quantitative evaluation of 5 diuretic drugs.

The Use of Antihypertensive Drugs as Coadjuvant Therapy in Cancer

Cancer is a complex group of diseases that constitute the second largest cause of mortality worldwide. The development of new drugs for treating this disease is a long and costly process, from the discovery of the molecule through testing in phase III clinical trials, a process during which most candidate molecules fail. The use of drugs currently employed for the management of other diseases (drug repurposing) represents an alternative for developing new medical treatments. Repurposing existing drugs is, in principle, cheaper and faster than developing new drugs. Antihypertensive drugs, primarily belonging to the pharmacological categories of angiotensin-converting enzyme inhibitors, angiotensin II receptors, direct aldosterone antagonists, β-blockers and calcium channel blockers, are commonly prescribed and have well-known safety profiles. Additionally, some of these drugs have exhibited pharmacological properties useful for the treatment of cancer, rendering them candidates for drug repurposing. In this review, we examine the preclinical and clinical evidence for utilizing antihypertensive agents in the treatment of cancer.

Prolonged Diuretic and Renoprotective Effects of a Xanthone Obtained from Garcinia achachairu Rusby in Normotensive and Hypertensive Rats

The previous study showed that 1,5,8-trihydroxy-4',5'-dimethyl-2H-pyrano(2,3 : 3,2)-4-(3-methylbut-2-enyl) xanthone (TDP) obtained from Garcinia achachairu Rusby (Clusiaceae) branches induces acute diuresis in normotensive (NTR) and spontaneously hypertensive rats (SHR) after 8 h of the experiment. In complementarity, the present study evaluated the prolonged diuretic and renoprotective effects of TDP in both NTR and SHR. The animals received, once a day, oral treatment with TDP (0.1 mg/kg), hydrochlorothiazide (10 mg/kg), or vehicle (VEH; 10 mL/kg). At the end of 7 days, the urine, blood, and kidney samples were collected for biochemical and histological analyzes. The urinary volume of both NTR and SHR after 7 days of treatment with the TDP was significantly increased, associated with augmented urinary electrolyte excretion levels. The treatments did not modify the urinary pH values nor the parameters analyzed in plasma (Na⁺, K⁺, Cl^-, and Ca²⁺). Concerning the renal analyzes, when compared with the VEH-treated NTR group, while the activity of the enzymes catalase (CAT) and N-acetyl-β-D-glucosaminidase (NAG), as well as nitrite levels, were increased, the generation of lipid hydroperoxides and the activity of the enzyme myeloperoxidase (MPO) were unaltered. On the other hand, the activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) and the levels of reduced glutathione (GSH) in kidney homogenates of the SHR group were decreased. However, TDP augmented the levels of GSH and GST activities and reduced the levels of nitrite and the activities of CAT and MPO, when compared with VEH-treated only SHR. Besides, the treatment with TDP alleviated the morphological changes of the renal corpuscle region of SHR. Together, these results revealed the prolonged diuretic effect of TDP and their renal protective effect by improving the antioxidative capacity.

Evaluation of single and combined effects of two pharmaceuticals on the marine gastropod Phorcus lineatus enzymatic activity under two different exposure periods

Pharmaceutical drugs are among the most used chemicals for human and veterinary medicines, aquaculture and agriculture. Pharmaceuticals are environmentally persistent, biologically active molecules, thereby having the potential to exert biological effects on non-target species. Among the most used pharmaceuticals, one may find salicylic acid (SA), a non-steroid anti-inflammatory drug (NSAID) that acts by inhibiting the enzymes cyclooxigenases; it is also possible to identify acetazolamide (ACZ), a diuretic that acts by inhibiting the activity of carbonic anhydrase (CA). In this work, the effects of both single and combined effects of these drugs were assessed on the marine gastropod Phorcus lineatus, by measuring key enzymatic activities, namely carbonic anhydrase (CA) and cyclooxygenase (COX), under two different exposure periods (14 and 28 days). We observed no straightforward pattern of enzymatic response in all treatments of both pharmaceuticals, on both analyzed tissues (gut and gills), and for both exposure regimes. We assume that this species is not responsive to the hereby tested pharmaceuticals, a finding that may be due to general mechanisms of response to adverse conditions, such as reduction of metabolism, of heart rate, of filtration rates, and to the increase production of mucus. All these functional adaptations can mitigate the deleterious effects caused by adverse conditions, without triggering biochemical responses. In conclusion, the species P. lineatus seems not to be sensitive in terms of these specific enzymatic pathways to these contaminants, under the adopted conditions.

Renal haemodynamic and protective effects of renoactive drugs in type 2 diabetes: Interaction with SGLT2 inhibitors

Diabetic kidney disease remains the leading cause of end-stage kidney disease and a major risk factor for cardiovascular disease. Large cardiovascular outcome trials and dedicated kidney trials have shown that sodium-glucose cotransporter (SGLT)2 inhibitors reduce cardiovascular morbidity and mortality and attenuate hard renal outcomes in patients with type 2 diabetes (T2D). Underlying mechanisms explaining these renal benefits may be mediated by decreased glomerular hypertension, possibly by vasodilation of the post-glomerular arteriole. People with T2D often receive several different drugs, some of which could also impact the renal vasculature, and could therefore modify both renal efficacy and safety of SGLT2 inhibition. The most commonly prescribed drugs that could interact with SGLT2 inhibitors on renal haemodynamic function include renin-angiotensin system inhibitors, calcium channel blockers and diuretics. Herein, we review the effects of these drugs on renal haemodynamic function in people with T2D and focus on studies that measured glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) with gold-standard techniques. In addition, we posit, based on these observations, potential interactions with SGLT2 inhibitors with an emphasis on efficacy and safety.

1,3,5,6-tetrahydroxyxanthone promotes diuresis, renal protection and antiurolithic properties in normotensive and hypertensive rats

OBJECTIVES

This study investigated the prolonged diuretic and renal effects of 1,3,5,6- tetrahydroxyxanthone (THX) in rats.

METHODS

Normotensive (NTR) and hypertensive rats (SHR) received orally the treatment with THX, hydrochlorothiazide or vehicle (VEH). Urine volume, urinary, plasma and kidney parameters were evaluated daily or at the end of 7 days of the experiment.

KEY FINDINGS

The urinary volume of both NTR and SHR were significantly augmented with the THX treatment, an effect associated with increased levels of urinary Na+ and K+, besides a Ca2+-sparing effect. As well, THX decreased the quantity of monohydrate crystals in urines from NTR and SHR when compared with VEH-group. Regarding the renal analyses, the glutathione levels and the activities of superoxide dismutase, glutathione S-transferase and myeloperoxidase in kidney homogenates of the SHR group were decreased. In contrast, the generation of lipid hydroperoxides (LOOH) and catalase activity was significantly increased. THX reduced the content of LOOH and increased nitrite levels in kidney homogenates obtained from SHR. Additionally, THX also augmented the levels of nitrite in the plasma from the SHR group.

CONCLUSIONS

Therefore, THX can be highlighted as a natural diuretic agent with renal protective properties and antiurolithic action.

Evaluation of the Diuretic Activity of Aqueous and 80% Methanol Extracts of Croton macrostachyus(Euphorbiaceae) Leaves in Saline-Loaded Rats

Background

Croton macrostachyus (Euphorbiaceae) extract is a folk medicine traditionally used for treating a number of disorders, including edematous conditions. The present study aimed to evaluate the diuretic effects of aqueous and 80% methanol leaf extracts of Croton macrostachyus in saline-loaded rats.

Methods

Rats of either sex were randomly assigned into eight groups of eight animals per group. The animals were treated with vehicle (distilled water), standard (furosemide 10 mg/kg), and three doses (100, 200, and 400 mg/kg) of aqueous and 80% methanol leaf extracts after loading of normal saline (15 mL/kg). Then, urine volume, electrolyte concentration, and pH were measured as parameters of evaluation. Concentrations of urinary Na⁺ K⁺, and Cl^– were determined and Na⁺:K⁺ and Cl⁻:Na⁺ + K⁺ ratios calculated to reveal possible mechanisms.

Results

The aqueous extract at 200 mg/kg had produced significant diuresis by hour 3, while the same dose of 80% methanol extract had produced substantial diuresis by the end of hour 4. Both extracts at 400 mg/kg produced significant diuresis from hour 2 to hour 5. In terms of effect on electrolysis, 400 mg/kg aqueous extract produced significant natriuresis, and a kaliuresis effect was observed for both extracts at higher doses and 200 mg/kg aqueous extract.

Conclusion

The findings collectively indicated that both aqueous and 80% methanol extract showed significant diuretic activity, thereby justifying the plant’s traditional use as a diuretic agent.

Optimal diuretic strategies in heart failure

Heart failure (HF) is one of the major causes of morbidity and mortality in the world. According to a 2019 American Heart Association report, about 6.2 million American adults had HF between 2013 and 2016, being responsible for almost 1 million admissions. As the population ages, the prevalence of HF is anticipated to increase, with 8 million Americans projected to have HF by 2030, posing a significant public health and financial burden. Acute decompensated HF (ADHF) is a syndrome characterized by volume overload and inadequate cardiac output associated with symptoms including some combination of exertional shortness of breath, orthopnea, paroxysmal nocturnal dyspnea (PND), fatigue, tissue congestion (e.g., peripheral edema) and decreased mentation. The pathology is characterized by hemodynamic abnormalities that result in autonomic imbalance with an increase in sympathetic activity, withdrawal of vagal activity and neurohormonal activation (NA) resulting in increased plasma volume in the setting of decreased sodium excretion, increased water retention and in turn an elevation of filling pressures. These neurohormonal changes are adaptive mechanisms which in the short term are associated with increased contractility of the left ventricular (LV) and improvement in cardiac output. But chronically, the failing heart is unable to overcome the excessive pressure and volume leading to worsening HF. The primary symptomatic management of ADHF includes intravenous (IV) diuresis to help with decongestion and return to euvolemic status. Even though diuretics have not been shown to provide any mortality benefit, they have been clinically proven to be of significant benefit in the acute decompensated phase, as well as in chronic management of HF. Loop diuretics remain the mainstay of therapy for symptomatic management of HF with use of thiazide diuretics for synergistic effect in the setting of diuretic resistance. Poor diuretic efficacy has been linked with higher mortality and increased rehospitalizations.

Effects of the NKCC1 inhibitors bumetanide, azosemide, and torasemide alone or in combination with phenobarbital on seizure threshold in epileptic and nonepileptic mice

The sodium-potassium-chloride (Na-K-Cl) cotransporter NKCC1 is found in the plasma membrane of a wide variety of cell types, including neurons, glia and endothelial cells in the brain. Increased expression of neuronal NKCC1 has been implicated in several brain disorders, including neonatal seizures and epilepsy. The loop diuretic and NKCC inhibitor bumetanide has been evaluated as an antiseizure agent alone or together with approved antiseizure drugs such as phenobarbital (PB) in pre-clinical and clinical studies with varying results. The equivocal efficacy of bumetanide may be a result of its poor brain penetration. We recently reported that the loop diuretic azosemide is more potent to inhibit NKCC1 than bumetanide. In contrast to bumetanide, azosemide is not acidic, which should favor its brain penetration. Thus, azosemide may be a promising alternative to bumetanide for treatment of brain disorders such as epilepsy. In the present study, we determined the effect of azosemide and bumetanide on seizure threshold in adult epileptic mice. A structurally related non-acidic loop diuretic, torasemide, which also blocks NKCC1, was included in the experiments. The drug effects were assessed by determing the maximal electroshock seizure threshold (MEST) in epileptic vs. nonepileptic mice. Epilepsy was induced by pilocarpine, which was shown to produce long-lasting increases in NKCC1 in the hippocampus, whereas MEST did not alter NKCC1 mRNA in this region. None of the three loop diuretics increased MEST or the effect of PB on MEST in nonepileptic mice. In epileptic mice, all three diuretics significantly increased PB's seizure threshold increasing efficacy, but the effect was variable upon repeated MEST determinations and not correlated with the drugs' diuretic potency. These data may indicate that inhibition of NKCC1 by loop diuretics is not an effective means of increasing seizure threshold in adult epilepsy.

The search for brain-permeant NKCC1 inhibitors for the treatment of seizures: Pharmacokinetic-pharmacodynamic modelling of NKCC1 inhibition by azosemide, torasemide, and bumetanide in mouse brain

Because of its potent inhibitory effect on the Na⁺-K⁺-2Cl^- symporter isotype 1 (NKCC1) in brain neurons, bumetanide has been tested with varying results for treatment of seizures that potentially evolve as a consequence of abnormal NKCC1 activity. However, because of its physicochemical properties, bumetanide only poorly penetrates into the brain. We previously demonstrated that NKCC1 can be also inhibited by azosemide and torasemide, which lack the carboxyl group of bumetanide and thus should be better brain-permeable. Here we studied the brain distribution kinetics of azosemide and torasemide in comparison with bumetanide in mice and used pharmacokinetic-pharmacodynamic modelling to determine whether the drugs reach NKCC1-inhibitory brain concentrations. All three drugs hardly distributed into the brain, which seemed to be the result of probenecid-sensitive efflux transport at the blood-brain barrier. When fractions unbound in plasma and brain were determined by equilibrium dialysis, only about 6-17% of the brain drug concentration were freely available. With the systemic doses (10 mg/kg i.v.) used, free brain concentrations of bumetanide and torasemide were in the NKCC1-inhibitory concentration range, while levels of azosemide were slightly below this range. However, all three drugs exhibited free plasma levels that would be sufficient to block NKCC1 at the apical membrane of brain capillary endothelial cells. These data suggest that azosemide and torasemide are interesting alternatives to bumetanide for treatment of seizures involving abnormal NKCC1 functionality, particularly because of their longer duration of action and their lower diuretic potency, which is an advantage in patients with seizures.

Pharmacokinetics and bioavailability of furosemide in sheep

The pharmacokinetics and bioavailability of furosemide were determined following intravenous (IV), intramuscular (IM), and subcutaneous (SC) administrations at 2.5 mg/kg dose in sheep. The study was conducted on six healthy sheep in a three-way, three-period, crossover pharmacokinetic design with a 15-day washout period. In first period, furosemide was randomly administered via IV to 2 sheep, IM to 2 sheep and SC to 2 sheep. In second and third periods, each sheep received furosemide via different routes of administration with the 15-day washout period. Plasma concentrations were determined using a high-performance liquid chromatography assay and analyzed by noncompartmental method. The mean total clearance and volume of distribution at steady state following IV administration were 0.24 L h^-1  kg^-1 and 0.17 L/kg, respectively. The elimination half-life was similar for all administration routes. The mean peak plasma concentrations of IM and SC administration were 10.33 and 3.18 μg/ml at 0.33 and 0.42 hr, respectively. The mean bioavailability of IM and SC administration was 97.91% and 37.98%, respectively. The IM injection of furosemide may be the alternative routes in addition to IV. However, further research is required to determine the effect of dose and route of administration on the clinical efficacy of furosemide in sheep.

Optimizing Precision of Hypertension Care to Maximize Blood Pressure Control: A Pilot Study Utilizing a Smartphone App to Incorporate Plasma Renin Activity Testing

Only half of patients with hypertension (HTN) respond to any given antihypertensive medication. Heterogeneity in pathophysiologic pathways underlying HTN is a major contributor. Personalizing antihypertensive therapy could improve blood pressure (BP) reduction. The objective of this study was to assess the effect of pragmatic implementation of a personalized plasma renin activity (PRA)‐based smartphone app on improving BP reduction. Patients with untreated or treated but uncontrolled HTN were recruited. BP and PRA were measured at baseline with final BP measured at 6 months. Patient’s information was entered into the app and treatment recommendations were returned. Clinicians were at liberty to follow or disregard the app’s recommendations. BP levels and percent BP control among patients whose clinicians did and did not follow the app’s recommendations were compared using independent t‐test and Fisher’s exact test, respectively. Twenty‐nine European American patients were included (38% women) with mean age of 52 ± 9 years and median PRA of 1.3 ng/mL/hr (interquartile range 0.5–3.1 ng/mL/hr). Participants whose clinicians followed the app’s recommendations (n = 16, 55%) as compared with those whose clinicians did not (n = 13, 45%), had a greater reduction in 6‐month systolic BP (−15 ± 21 vs. −3 ± 21 mm Hg; adjusted‐P = 0.1) and diastolic BP (−8 ± 8 vs. −1 ± 8 mm Hg; adjusted‐P = 0.04). BP control at 6 months tended to be greater among patients whose clinicians accepted the app’s recommendations vs. those whose clinicians did not (63% vs. 23%, P = 0.06). This pilot study demonstrates that acceptance of the app’s recommendations was associated with a greater BP reduction. Future studies to confirm these pilot findings are warranted.

The acute diuretic effects with low-doses of natural prenylated xanthones in rats

The diuretic effect of 3-demethyl-2-geranyl-4-prenylbellidypholine xanthone (DGP) and 1,5,8-trihydroxy-4',5'-dimethyl-2H-pyrano(2,3:3,2)-4-(3-methylbut-2-enyl) xanthone (TDP), two natural prenylated xanthones, was investigated in female normotensive (NTR) and spontaneously hypertensive rats (SHR). The rats received a single treatment with DGP, TDP, hydrochlorothiazide (HCTZ), or vehicle (VEH) after an oral load of physiological saline. The effects of DGP and TDP in combination with diuretics of clinical use, as well as with L-NAME, atropine and indomethacin were also explored. The urinary parameters were measured at the end of the 8-h experiment. When orally given to rats, DGP was able to increase the urine volume, at doses of 0.03-0.3 mg/kg, associated with a K⁺-sparing effect. TDP, in turn, at doses of 0.03-0.3 mg/kg, induced diuresis and saluresis (i.e. augmented urinary levels of Na⁺ and Cl^-) in NTR, while decreased the urinary content of Ca²⁺ in both NTR and SHR. The combination with HCTZ, but not with furosemide or amiloride, significantly enhanced DGP and TDP induced diuresis, which was accompanied by an increase of the electrolytes content in the urine. Instead, amiloride in combination with DGP or TDP enhanced urinary Na⁺ and Cl^- and decreased K⁺ elimination. Furthermore, the effect of DGP and TDP were heightened after pretreatment with L-NAME. While atropine was able to prevent DGP-induced diuresis, the pretreatment with indomethacin precluded TDP-induced diuresis. Besides, TDP exerted protective effects against urinary calcium oxalate crystals formation. Taken together, our data revealed the diuretic effect of two xanthones in rats and their possible underlying mode of action.

Tolerance of torasemide in cats with congestive heart failure: a retrospective study on 21 cases (2016-2019)

BACKGROUND

In dogs with congestive heart failure (CHF), the efficacy of torasemide, a loop diuretic, has been demonstrated. However, unlike in dogs and humans little has been described about the use of torasemide in the cat with spontaneous CHF. The objectives of this retrospective study were therefore to describe the therapeutic use of oral torasemide in cats with spontaneous CHF, document its potential adverse effects while reporting the clinical course of this feline population following torasemide administration in addition to standard medical therapy.

RESULTS

Medical records of 21 client-owned cats with CHF (median age = 10.6 years [interquartile range (IQR) = 6.5-11.2]) receiving torasemide were reviewed. Data collected included torasemide dosages, other concurrent medications, physical examination features, echocardiographic data, and potential adverse effects during follow-up. A survival analysis was performed to estimate the time from diagnosis to cardiac death. Dyspnea related to CHF was identified in all cats (pleural effusion [8/21], pulmonary edema [5/21] or both [8/21]), associated with ascites in 4/21 cats. The CHF cause was determined by echocardiography in all cats: hypertrophic (n = 10), restrictive (n = 6), arrhythmogenic right ventricular (n = 3), dilated (n = 1) cardiomyopathies, and aortic valve abnormality (n = 1). At initiation, median torasemide dosage was 0.21 mg/kg [IQR = 0.17-0.23] q24h. Clinical signs declined in most cats (20/21) during the first 2 weeks with no remarkable adverse events. Median survival time after torasemide prescription was 182 days [IQR = 46-330]. A contemporary control group including 54 cats with CHF, receiving furosemide as sole loop diuretic treatment was compared with the study group. Median (IQR) survival time of cats in the control group was not significatively different (p = 0.962) from that of the torasemide group, i.e., 148 days (9-364), although the torasemide group included significantly more cats with recurrent episodes of CHF (52%) that the control group (19%).

CONCLUSIONS

This case series demonstrates that torasemide can be used in cats with spontaneous CHF. This therapeutic interest needs to be confirmed by prospective clinical trials.

Tolerance of torasemide in cats with congestive heart failure: a retrospective study on 21 cases (2016-2019)

BACKGROUND

In dogs with congestive heart failure (CHF), the efficacy of torasemide, a loop diuretic, has been demonstrated. However, unlike in dogs and humans little has been described about the use of torasemide in the cat with spontaneous CHF. The objectives of this retrospective study were therefore to describe the therapeutic use of oral torasemide in cats with spontaneous CHF, document its potential adverse effects while reporting the clinical course of this feline population following torasemide administration in addition to standard medical therapy.

RESULTS

Medical records of 21 client-owned cats with CHF (median age = 10.6 years [interquartile range (IQR) = 6.5-11.2]) receiving torasemide were reviewed. Data collected included torasemide dosages, other concurrent medications, physical examination features, echocardiographic data, and potential adverse effects during follow-up. A survival analysis was performed to estimate the time from diagnosis to cardiac death. Dyspnea related to CHF was identified in all cats (pleural effusion [8/21], pulmonary edema [5/21] or both [8/21]), associated with ascites in 4/21 cats. The CHF cause was determined by echocardiography in all cats: hypertrophic (n = 10), restrictive (n = 6), arrhythmogenic right ventricular (n = 3), dilated (n = 1) cardiomyopathies, and aortic valve abnormality (n = 1). At initiation, median torasemide dosage was 0.21 mg/kg [IQR = 0.17-0.23] q24h. Clinical signs declined in most cats (20/21) during the first 2 weeks with no remarkable adverse events. Median survival time after torasemide prescription was 182 days [IQR = 46-330]. A contemporary control group including 54 cats with CHF, receiving furosemide as sole loop diuretic treatment was compared with the study group. Median (IQR) survival time of cats in the control group was not significatively different (p = 0.962) from that of the torasemide group, i.e., 148 days (9-364), although the torasemide group included significantly more cats with recurrent episodes of CHF (52%) that the control group (19%).

CONCLUSIONS

This case series demonstrates that torasemide can be used in cats with spontaneous CHF. This therapeutic interest needs to be confirmed by prospective clinical trials.

The Peculiarity of Process and Treatment of Arterial Hypertension in Patients with Type 2 Diabetes Mellitus

Arterial hypertension (AH) is powerful and modifying factor of developing macrovascular and microvascular complications of diabetes. Patients with AH and diabetes belong to group with high and very high levels risk of developing cardiovascular complications and chronic kidney disease. The combination of type 2 diabetes mellitus and AH dramatically increases the risk of developing terminal stages of microvascular and macrovascular diabetic complications: blindness, end-stage chronic kidney disease, amputation of the lower extremities, myocardial infarction, cerebral stroke, worsens the patients prognosis and quality of life. There is ample evidence that blood pressure control in diabetic patients may be critical for improving long-term prognosis. This observation does not lose its relevance even with the emergence of new antidiabetic drugs with proven cardio- and nephroprotective effects. Modern clinical researchers and meta-analysis show the priority of combined antihypertensive therapy, which increases the efficacy of blood pressure correction and prophylaxis of long-term complications in patients with type 2 diabetes. In this article we want to pay attention to features of AH in patients with diabetes, to bi-directional pathogenic mechanisms, to discuss the new algorithms of the treatment and therapeutic needs of these patients. It is important to accent the understanding of the integrity and unity of pathogenic mechanisms which are needed in correction. Innovative antihyperglycemic therapy demonstrates the ability of blood pressure decrease. The synergy of effects let us successfully realize the strategy of multi-factor control and reduce a risk of micro- and macrovascular complications.

Unraveling the molecular pathobiology of vocal fold systemic dehydration using an in vivo rabbit model

Vocal folds are a viscoelastic multilayered structure responsible for voice production. Vocal fold epithelial damage may weaken the protection of deeper layers of lamina propria and thyroarytenoid muscle and impair voice production. Systemic dehydration can adversely affect vocal function by creating suboptimal biomechanical conditions for vocal fold vibration. However, the molecular pathobiology of systemically dehydrated vocal folds is poorly understood. We used an in vivo rabbit model to investigate the complete gene expression profile of systemically dehydrated vocal folds. The RNA-Seq based transcriptome revealed 203 differentially expressed (DE) vocal fold genes due to systemic dehydration. Interestingly, function enrichment analysis showed downregulation of genes involved in cell adhesion, cell junction, inflammation, and upregulation of genes involved in cell proliferation. RT-qPCR validation was performed for a subset of DE genes and confirmed the downregulation of DSG1, CDH3, NECTIN1, SDC1, S100A9, SPINK5, ECM1, IL1A, and IL36A genes. In addition, the upregulation of the transcription factor NR4A3 gene involved in epithelial cell proliferation was validated. Taken together, these results suggest an alteration of the vocal fold epithelial barrier independent of inflammation, which could indicate a disruption and remodeling of the epithelial barrier integrity. This transcriptome provides a first global picture of the molecular changes in vocal fold tissue in response to systemic dehydration. The alterations observed at the transcriptional level help to understand the pathobiology of dehydration in voice function and highlight the benefits of hydration in voice therapy.

Redefining diuretics use in hypertension: why select a thiazide-like diuretic?

Diuretics are listed in hypertension guidelines as one of three equally weighted first-line treatment options. In order to differentiate between antihypertensives, a lot of discussion has been directed at side effect profiles and as a result, has created a perhaps disproportionate fear of the metabolic effects that can be associated with diuretics. Data, however, show that the risk of a clinically meaningful change in laboratory parameters is very low, whereas the benefits of volume control and natriuresis are high and the reductions in morbidity and mortality are clinically significant. Moreover, as clinically significant differences in safety and efficacy profiles exist among diuretics, several international guidelines have started making a distinction between thiazides (hydrochlorothiazide) and thiazide-like (chlorthalidone, indapamide) diuretics; and some of them now recommend longer acting thiazide-like diuretics. In time, pending more data, chlorthalidone and indapamide may need to be subdivided further into separate classifications.