Structural bases for Na+-Cl- cotransporter inhibition by thiazide diuretic drugs and activation by kinases.

The Na+-Cl- cotransporter (NCC) drives salt reabsorption in the kidney and plays a decisive role in balancing electrolytes and blood pressure. Thiazide and thiazide-like diuretics inhibit NCC-mediated renal salt retention and have been cornerstones for treating hypertension and edema since the 1950s. Here we determine NCC co-structures individually complexed with the thiazide drug hydrochlorothiazide, and two thiazide-like drugs chlorthalidone and indapamide, revealing that they fit into an orthosteric site and occlude the NCC ion translocation pathway. Aberrant NCC activation by the WNKs-SPAK kinase cascade underlies Familial Hyperkalemic Hypertension, but it remains unknown whether/how phosphorylation transforms the NCC structure to accelerate ion translocation. We show that an intracellular amino-terminal motif of NCC, once phosphorylated, associates with the carboxyl-terminal domain, and together, they interact with the transmembrane domain. These interactions suggest a phosphorylation-dependent allosteric network that directly influences NCC ion translocation.

Thiazide Dose, Urine Calcium, and Symptomatic Kidney Stone Events.

This cohort study examines the association between thiazide dose and urine calcium reduction and correlates urine calcium changes with the occurrence of symptomatic kidney stone events.

Pathophysiological role of Na-Cl cotransporter in kidneys, blood pressure, and metabolism.

The Na-Cl cotransporter (NCC) is a well-recognized regulator of ion transportation in the kidneys that facilitates Na+ reabsorption in the distal convoluted tubule. It is also the pharmacologic inhibitory target of thiazide diuretics, a class of front-line antihypertensive agents that have been widely used for decades. NCC is a potent regulator of Na+ reabsorption and homeostasis. Hence, its overactivation and suppression lead to hypertension and hypotension, respectively. Genetic mutations that affect NCC function contribute to several diseases such as Gordon and Gitelman syndromes. We summarized the role of NCC in various physiologic processes and pathological conditions, such as maintaining ion and water homeostasis, controlling blood pressure, and influencing renal physiology and injury. In addition, we discussed the recent advancements in understanding cryo-EM structure of NCC, the regulatory mechanisms and binding mode of thiazides with NCC, and novel physiologic implications of NCC in regulating the cross-talk between the immune system and adipose tissue or the kidneys. This review contributes to a comprehensive understanding of the pivotal role of NCC in maintaining ion homeostasis, regulating blood pressure, and facilitating kidney function and NCC's novel role in immune and metabolic regulation.

Effects of thiazides and new findings on kidney stones and dysglycemic side effects.

Thiazide and thiazide-like diuretics (thiazides) belong to the most frequently prescribed drugs worldwide. By virtue of their natriuretic and vasodilating properties, thiazides effectively lower blood pressure and prevent adverse cardiovascular outcomes. In addition, through their unique characteristic of reducing urine calcium, thiazides are also widely employed for the prevention of kidney stone recurrence and reduction of bone fracture risk. Since their introduction into clinical medicine in the early 1960s, thiazides have been recognized for their association with metabolic side effects, particularly impaired glucose tolerance, and new-onset diabetes mellitus. Numerous hypotheses have been advanced to explain thiazide-induced glucose intolerance, yet underlying mechanisms remain poorly defined. Regrettably, the lack of understanding and unpredictability of these side effects has prompted numerous physicians to refrain from prescribing these effective, inexpensive, and widely accessible drugs. In this review, we outline the pharmacology and mechanism of action of thiazides, highlight recent advances in the understanding of thiazide-induced glucose intolerance, and provide an up-to-date discussion on the role of thiazides in kidney stone prevention.

Comparative analysis of real-world adherence and persistence patterns with vibegron, mirabegron, and anticholinergics in patients with overactive bladder: A retrospective claims study.

INTRODUCTION: Vibegron is a selective ß3-adrenergic receptor agonist that was approved by the US Food and Drug Administration in December 2020 for the treatment of overactive bladder in adults. This retrospective study assessed US pharmacy claims data to evaluate the real-world adherence and persistence of vibegron compared with mirabegron and with anticholinergics. MATERIALS AND METHODS: This analysis used the Optum Research Database to identify adults with ≥1 pharmacy claim for vibegron, mirabegron, or an anticholinergic from April 1, 2021, to August 31, 2022. Patients had ≥ 90 days of continuous commercial or Medicare medical and pharmacy coverage preindex and ≥ 60 days of continuous pharmacy coverage postindex. Two independent propensity-score models matched patients treated with (1) vibegron versus mirabegron and (2) vibegron versus anticholinergics on key variables such as demographics and clinical characteristics, index copay, days' supply, and time of entry into analysis (index quarter). Adherence was measured by proportion of days covered (PDC) from index to the end of follow-up and was defined as PDC ≥ 80%. Persistence was defined as days to discontinuation of index medication (first 30-day gap) or end of follow-up. RESULTS: The matched vibegron and mirabegron cohorts included 4921 and 9842 patients, respectively, and the matched vibegron and anticholinergic cohorts included 4676 and 9352 patients, respectively. Patients receiving vibegron had greater mean PDC versus patients receiving mirabegron (0.67 vs. 0.64, respectively; p < 0.001) or anticholinergics (0.67 vs. 0.58; p < 0.001). A greater percentage of patients receiving vibegron were adherent versus those receiving mirabegron (49.0% vs. 45.1%, respectively; p < 0.001) or anticholinergics (49.1% vs. 38.5%; p < 0.001). Persistence was longer with vibegron compared with both mirabegron (median [95% CI], 171 [159-182] vs. 128 [122-137] days, respectively; p < 0.001) and anticholinergics (172 [159-183] vs. 91 [91] days; p < 0.001). CONCLUSION: In this retrospective analysis of pharmacy claims data, patients receiving vibegron exhibited significantly higher adherence and demonstrated longer persistence in comparison to matched patient cohorts receiving either mirabegron or anticholinergics.

Thiazide-associated hyponatremia in arterial hypertension patients: A nationwide population-based cohort study.

OBJECTIVE: Thiazides are the first-line treatment for hypertension, however, they have been associated with hospitalizations for thiazide-associated hyponatremia (TAH). The aim of this study was to evaluate the risk of TAH and other drug-associated hyponatremia in a Korean population. METHODS: The study used big data from the National Health Insurance Sharing Service of 1,943,345 adults treated for hypertension from January 2014 to December 2016. The participants were divided into two groups based on the use of thiazides. Cox proportional hazard models were used to identify independent risk factors for the occurrence of hyponatremia. RESULTS: The study found that hyponatremia-related hospitalizations were significantly higher in the thiazide group than the control group (2.19% vs. 1.45%). The risk increased further with concurrent use of other diuretics or desmopressin, and thiazide+spironolactone+desmopressin and hospitalization risk further increased (4.0 and 6.9 times). Multivariate analysis showed that hyponatremia occurrence increased with age, diabetes mellitus, depression, and thiazide use (hazard ratio = 1.436, p < 0.001). The thiazide group had better 6-year overall survival than the control group but had more fractures and hyponatremia. CONCLUSIONS: Thiazide use is associated with an increased risk of hyponatremia and related complications. However, the mortality rate decreased in those who received thiazides, suggesting that thiazide use itself is not harmful and may help decrease complications and improve prognosis with proper, cautious use in high-risk patients.

Thiazides for kidney stone recurrence prevention.

PURPOSE OF REVIEW: Kidney stones are the most common condition affecting the kidney, and characterized by a high rate of recurrence. Thiazide and thiazide-like diuretics (thiazides) are commonly prescribed to prevent the recurrence of kidney stones. This review offers a comprehensive up-to-date assessment of the evidence supporting the use of thiazides for kidney stone recurrence prevention, highlights potential harms associated with treatment, and identifies areas of knowledge that require further investigation. RECENT FINDINGS: The clinical routine to prescribe thiazides for kidney stone prevention has recently been challenged by the findings of the large NOSTONE trial that failed to show superiority of hydrochlorothiazide at doses up to 50 mg daily over placebo in preventing a composite of clinical or radiological recurrence in patients at high risk of recurrence. Yet, adverse events such as new onset diabetes mellitus and gout were more common in patients receiving hydrochlorothiazide compared to placebo. As demonstrated by a novel meta-analysis presented in this review encompassing all randomized placebo-controlled trials with thiazide monotherapy, current trial evidence does not indicate that thiazide monotherapy is significantly better than placebo in preventing kidney stone recurrence. SUMMARY: Given the limited efficacy and possible adverse effects, we advocate for a restrictive use of thiazides for kidney stone recurrence prevention. Clearly, there remains a high unmet medical need for effective, targeted therapies to prevent recurrence of kidney stones.

Comparative safety and effectiveness of angiotensin converting enzyme inhibitors and thiazides and thiazide-like diuretics under strict monotherapy.

Previous work comparing safety and effectiveness outcomes for new initiators of angiotensin converting-enzyme inhibitors (ACEi) and thiazides demonstrated more favorable outcomes for thiazides, although cohort definitions allowed for addition of a second antihypertensive medication after a week of monotherapy. Here, we modify the monotherapy definition, imposing exit from cohorts upon addition of another antihypertensive medication. We determine hazard ratios (HR) for 55 safety and effectiveness outcomes over six databases and compare results to earlier findings. We find, for all primary outcomes, statistically significant differences in effectiveness between ACEi and thiazides were not replicated (HRs: 1.11, 1.06, 1.12 for acute myocardial infarction, hospitalization with heart failure and stroke, respectively). While statistical significance is similarly lost for several safety outcomes, the safety profile of thiazides remains more favorable. Our results indicate a less striking difference in effectiveness of thiazides compared to ACEi and reflect some sensitivity to the monotherapy cohort definition modification.

Prescribing cascades of antigout medications from thiazide diuretics in gout-naïve hypertensive adults receiving first-line pharmacological management.

Prescribing cascade is a significant clinical problem but is often overlooked. We explore the incidence of the prescribing cascades of antigout medications related to thiazide treatment in gout-naïve hypertensive adults newly exposed to the pharmacological treatment. This population-based, retrospective cohort study used the Taiwan National Health Insurance Registry Database. Gout-naïve hypertensive adults who were newly dispensed first-line antihypertensive drugs between January 1, 2000, and December 31, 2016, were enrolled. Patients were divided into the thiazide group (n = 4192) and the non-thiazide group (n = 81,083). The non-thiazide group included patients who received an angiotensin-converting enzyme inhibitor, angiotensin II receptor blocker, calcium channel blocker, or beta-blocker. The study utilized propensity score matching and multivariable Cox regression models to investigate the prescribing cascade of antigout agents following antihypertensive treatment, adjusting for factors like age, sex, comorbidities, and concurrent medications. After propensity score matching, each group consisted of 4045 patients, with the thiazide group exhibiting a higher risk of being prescribed antigout medications across different time intervals post-treatment initiation. Specifically, adjusted hazard ratios (aHRs) for the thiazide group were 2.23, 2.07, and 2.41 for < 30 days, 31-180 days, and > 180 days, respectively, indicating a sustained and significant risk over time. Comparative analyses revealed thiazide diuretics were associated with a higher risk of antigout medication prescriptions compared to other antihypertensive classes, particularly evident after 180 days. Subgroup analyses across various demographics and comorbidities consistently showed an increased risk in the thiazide cohort. Gout-naïve hypertensive adults newly dispensed thiazide had a higher risk of subsequently adding antigout agents than those taking other first-line antihypertensive medications. The awareness and interruption of these prescribing cascades are critical to improving patient safety.

Circulating microRNA Biomarkers of Thiazide Response in Hypertension.

BACKGROUND: Thiazide diuretics are the second most frequently prescribed class of antihypertensives, but up to 50% of patients with hypertension have minimal antihypertensive response to thiazides. We explored circulating microRNAs (miRNAs) in search of predictive biomarkers of thiazide response. METHODS AND RESULTS: We profiled 754 miRNAs in baseline plasma samples of 36 hypertensive European American adults treated with hydrochlorothiazide, categorized into responders (n=18) and nonresponders (n=18) on the basis of diastolic blood pressure response to hydrochlorothiazide. miRNAs with ≥2.5-fold differential expression between responders and nonresponders were considered for validation in 3 cohorts (n=50 each): hydrochlorothiazide-treated European Americans, chlorthalidone-treated European Americans, and hydrochlorothiazide-treated Black individuals. Different blood pressure phenotypes including categorical (responder versus nonresponder) and continuous diastolic blood pressure and systolic blood pressure were tested for association with the candidate miRNA expression using multivariate regression analyses adjusting for age, sex, and baseline blood pressure. After quality control, 74 miRNAs were available for screening, 19 of which were considered for validation. In the validation cohort, miR-193b-3p and 30d-5p showed significant associations with continuous SBP or diastolic blood pressure response or both, to hydrochlorothiazide in European Americans at Benjamini-Hochberg adjusted P<0.05. In the combined analysis of validation cohorts, let-7g (odds ratio, 0.6 [95% CI, 0.4-0.8]), miR-142-3p (odds ratio, 1.1 [95% CI, 1.0, 1.2]), and miR-423-5p (odds ratio, 0.7 [95% CI, 0.5-0.9]) associated with categorical diastolic blood pressure response at Benjamini-Hochberg adjusted P<0.05. Predicted target genes of the 5 miRNAs were mapped to key hypertension pathways: lysine degradation, fatty acid biosynthesis, and metabolism. CONCLUSIONS: The above identified circulating miRNAs may have a potential for clinical use as biomarkers for thiazide diuretic selection in hypertension. REGISTRATION: URL: ClinicalTrials.gov. Unique identifiers: NCT00246519, NCT01203852, NCT00005520.

[Change in the prevention of kidney stones]. / Lithiase rénale, un changement de paradigme?

Kidney stone is one of the most frequent disorders of the urinary tract. Once the stone has passed, the management should be oriented on prevention. If changes in lifestyle and diet should be implemented in a true therapeutic education of the patient, prescription of drugs has been recently challenged by the NOSTONE trial. This randomized controlled trial did not show any benefit of hydrochlorothiazide in the prevention of recurrence of kidney stone event in patients with calcium-containing stone. Therefore, prescription of thiazide in the sole purpose of decreasing kidney stone recurrence should be limited and the risk/benefit of this treatment should be carefully balanced for each case.

La maladie rénale lithiasique est une des affections les plus fréquentes de l'axe urinaire. Une fois l'expulsion du calcul obtenue, la prise en charge est orientée sur la prévention. Si les modifications diététiques et comportementales doivent être implémentées dans le cadre d'une véritable éducation thérapeutique, la prescription de traitements médicamenteux préventifs est remise en question par l'étude NOSTONE. Cette étude randomisée contrôlée n'a pas montré de bénéfice de l'hydrochlorothiazide dans la prévention de la récidive des calculs à contenu calcique. Dès lors, la prescription de thiazide en monothérapie dans le but de diminuer les récidives de calculs doit être limitée et le risque/bénéfice soigneusement évalué dans chaque cas.

[Thiazid diuretics : some useful considerations in clinical practice]. / Diurétiques thiazidiques. Quelques considérations utiles en pratique clinique.

Thiazide diuretics are an essential part of the treatment of hypertension, which affects nearly a third of the world's population. Hydrochlorothiazide is the most widely used member of this class, due to its long availability on the market and the many combinations available with other substances. Other analogues of this class exist, with notable advantages from a clinical point of view, recognized under the name of thiazide-like. This article reviews some of the considerations in clinical practice concerning the different types of thiazides currently available in Switzerland.

Les diurétiques thiazidiques font partie des traitements de premier choix dans la prise en charge de l'hypertension artérielle, touchant près d'un tiers de la population mondiale. L'hydrochlorothiazide est le représentant de cette classe médicamenteuse le plus utilisé dans les combinaisons antihypertensives en Suisse. D'autres analogues de cette classe existent sur le marché, avec des avantages notables du point de vue clinique, reconnus sous la dénomination de thiazides-like. Le choix de l'utilisation d'un diurétique thiazidique repose avant tout sur les indications et les contre-indications relatives à cette classe. Cet article propose une revue de quelques considérations en pratique clinique sur les différents types de thiazides actuellement disponibles en Suisse.

Kinase Scaffold Cab39 Is Necessary for Phospho-Activation of the Thiazide-Sensitive NCC.

BACKGROUND: Potassium regulates the WNK (with no lysine kinase)-SPAK (STE20/SPS1-related proline/alanine-rich kinase) signaling axis, which in turn controls the phosphorylation and activation of the distal convoluted tubule thiazide-sensitive NCC (sodium-chloride cotransporter) for sodium-potassium balance. Although their roles in the kidney have not been investigated, it has been postulated that Cab39 (calcium-binding protein 39) or Cab39l (Cab39-like) is required for SPAK/OSR1 (oxidative stress response 1) activation. This study demonstrates how they control the WNK-SPAK/OSR1-NCC pathway. METHODS: We created a global knockout of Cab39l and a tamoxifen-inducible, NCC-driven, Cab39 knockout. The 2 lines were crossed to generate Cab39-DKO (Cab39 double knockout) animals. Mice were studied under control and low-potassium diet, which activates WNK-SPAK/OSR1-NCC phosphorylation. Western blots were used to assess the expression and phosphorylation of proteins. Blood and urine electrolytes were measured to test for compromised NCC function. Immunofluorescence studies were conducted to localize SPAK and OSR1. RESULTS: Both Cab39l and Cab39 are expressed in distal convoluted tubule, and only the elimination of both leads to a striking absence of NCC phosphorylation. Cab39-DKO mice exhibited a loss-of-NCC function, like in Gitelman syndrome. In contrast to the apical membrane colocalization of SPAK with NCC in wild-type mice, SPAK and OSR1 become confined to intracellular puncta in the Cab39-DKO mice. CONCLUSIONS: In the absence of Cab39 proteins, NCC cannot be phosphorylated, resulting in a Gitelman-like phenotype. Cab39 proteins function to localize SPAK at the apical membrane with NCC, reminiscent of the Cab39 yeast homolog function, translocating kinases during cytokinesis.

Diuretic Tolerance to Repeated-Dose Furosemide in Infants Born Very Preterm with Bronchopulmonary Dysplasia.

OBJECTIVES: To assess the presence and timing of furosemide diuretic tolerance in infants with bronchopulmonary dysplasia (BPD), and to determine if tolerance is modified by thiazide co-administration. STUDY DESIGN: We performed a retrospective cohort study among infants born very preterm with BPD exposed to repeated-dose furosemide for 72 hours, measuring net fluid balance (total intake minus total output) as a surrogate of diuresis in the 3 days before and after exposure. The primary comparison was the difference in fluid balance between the first and third 24 hours of furosemide exposure. We fit a general linear model for within-subject repeated measures of fluid balance over time, with thiazide co-administration as an interaction variable. Secondary analyses included an evaluation of weight trajectories over time. RESULTS: In 83 infants, median fluid balance ranged between + 43.6 and + 52.7 ml/kg/d in the 3 days prior to furosemide exposure. Fluid balance decreased to a median of + 29.1 ml/kg/d in the first 24 hours after furosemide, but then increased to +47.5 ml/kg/d by the third 24-hour interval, consistent with tolerance (P < .001). Thiazides did not modify the change in fluid balance during furosemide exposure for any time-period. Weight decreased significantly in the first 24 hours after furosemide and increased thereafter (P < .001). CONCLUSIONS: The net fluid balance response to furosemide decreases rapidly during repeated-dose exposures in infants with BPD, consistent with diuretic tolerance. Clinicians should consider this finding in the context of an infant's therapeutic goals. Further research efforts to identify safe and effective furosemide dosage strategies are needed.

Dysregulation of the WNK4-SPAK/OSR1 pathway has a minor effect on baseline NKCC2 phosphorylation.

The with-no-lysine kinase 4 (WNK4)-sterile 20/SPS-1-related proline/alanine-rich kinase (SPAK)/oxidative stress-responsive kinase 1 (OSR1) pathway mediates activating phosphorylation of the furosemide-sensitive Na+-K+-2Cl- cotransporter (NKCC2) and the thiazide-sensitive NaCl cotransporter (NCC). The commonly used pT96/pT101-pNKCC2 antibody cross-reacts with pT53-NCC in mice on the C57BL/6 background due to a five amino acid deletion. We generated a new C57BL/6-specific pNKCC2 antibody (anti-pT96-NKCC2) and tested the hypothesis that the WNK4-SPAK/OSR1 pathway strongly regulates the phosphorylation of NCC but not NKCC2. In C57BL/6 mice, anti-pT96-NKCC2 detected pNKCC2 and did not cross-react with NCC. Abundances of pT96-NKCC2 and pT53-NCC were evaluated in Wnk4-/-, Osr1-/-, Spak-/-, and Osr1-/-/Spak-/- mice and in several models of the disease familial hyperkalemic hypertension (FHHt) in which the CUL3-KLHL3 ubiquitin ligase complex that promotes WNK4 degradation is dysregulated (Cul3+/-/Δ9, Klhl3-/-, and Klhl3R528H/R528H). All mice were on the C57BL/6 background. In Wnk4-/- mice, pT53-NCC was almost absent but pT96-NKCC2 was only slightly lower. pT53-NCC was almost absent in Spak-/- and Osr1-/-/Spak-/- mice, but pT96-NKCC2 abundance did not differ from controls. pT96-NKCC2/total NKCC2 was slightly lower in Osr1-/- and Osr1-/-/Spak-/- mice. WNK4 expression colocalized not only with NCC but also with NKCC2 in Klhl3-/- mice, but pT96-NKCC2 abundance was unchanged. Consistent with this, furosemide-induced urinary Na+ excretion following thiazide treatment was similar between Klhl3-/- and controls. pT96-NKCC2 abundance was also unchanged in the other FHHt mouse models. Our data show that disruption of the WNK4-SPAK/OSR1 pathway only mildly affects NKCC2 phosphorylation, suggesting a role for other kinases in NKCC2 activation. In FHHt models NKCC2 phosphorylation is unchanged despite higher WNK4 abundance, explaining the thiazide sensitivity of FHHt.NEW & NOTEWORTHY The renal cation cotransporters NCC and NKCC2 are activated following phosphorylation mediated by the WNK4-SPAK/OSR1 pathway. While disruption of this pathway strongly affects NCC activity, effects on NKCC2 activity are unclear since the commonly used phospho-NKCC2 antibody was recently reported to cross-react with phospho-NCC in mice on the C57BL/6 background. Using a new phospho-NKCC2 antibody specific for C57BL/6, we show that inhibition or activation of the WNK4-SPAK/OSR1 pathway in mice only mildly affects NKCC2 phosphorylation.

Fall risk and cardiovascular outcomes of first-line antihypertensive medications in nursing home residents.

BACKGROUND: Little evidence exists about the comparative effects of first-line antihypertensive medications (i.e., renin-angiotensin-aldosterone converting enzyme inhibitors (RAASi), amlodipine, or thiazide diuretics) in older adults with limited life expectancy. We compared the rates of injurious falls and short-term cardiovascular events between different first-line antihypertensive medication classes in adults receiving care in nursing homes (NH). METHODS: This was a retrospective cohort of Medicare fee-for-service beneficiaries receiving care in NHs. Patients newly dispensed first-line antihypertensive medications were identified using Part D claims (2015-2018) and linked with clinical assessments (i.e., Minimum Data Set). Fall-related injuries (FRI), hip fractures, and major adverse cardiac events (MACE) outcomes were identified using hospitalization claims. Patients were followed from the date of antihypertensive dispensing until the occurrence of outcomes, death, disenrollment, or 6-month follow-up. Inverse-probability-of-treatment-weighted (IPTW) cause-specific hazards regression models were used to compare outcomes between patients who were new users of RAASi, amlodipine, or thiazides. RESULTS: Our cohort included 16,504 antihypertensive users (RAASi, n = 9574; amlodipine, n = 5049; thiazide, n = 1881). Mean age was 83.5 years (± 8.2), 70.6% were female, and 17.2% were non-white race. During a mean follow-up of 5.3 months, 326 patients (2.0%) experienced an injurious fall, 1590 (9.6%) experienced MACE, and 2123 patients (12.9%) died. The intention-to-treat IPTW hazard ratio (HR) for injurious falls for amlodipine (vs RAASi) use was 0.85 (95% confidence interval (CI) 0.66-1.08) and for thiazides (vs RAASi) was 1.22 (95% CI 0.88-1.66). The rates of MACE were similar between those taking anti-hypertensive medications. Thiazides were discontinued more often than other classes; however, inferences were largely unchanged in as-treated analyses. Subgroup analyses were generally consistent. CONCLUSIONS: Older adults with limited life expectancy experience similar rates of injurious falls and short-term cardiovascular events after initiating any of the first-line antihypertensive medications.

From Fish Physiology to Human Disease: The Discovery of the NCC, NKCC2, and the Cation-Coupled Chloride Cotransporters.

The renal Na-K-2Cl and Na-Cl cotransporters are the major salt reabsorption pathways in the thick ascending limb of Henle loop and the distal convoluted tubule, respectively. These transporters are the target of the loop and thiazide type diuretics extensively used in the world for the treatment of edematous states and arterial hypertension. The diuretics appeared in the market many years before the salt transport systems were discovered. The evolving of the knowledge and the cloning of the genes encoding the Na-K-2Cl and Na-Cl cotransporters were possible thanks to the study of marine species. This work presents the history of how we came to know the mechanisms for the loop and thiazide type diuretics actions, the use of marine species in the cloning process of these cotransporters and therefore in the whole solute carrier cotransproters 12 (SLC12) family of electroneutral cation chloride cotransporters, and the disease associated with each member of the family.

Comparison of Class-Specific Side Effects Across Preventative Pharmacologic Therapies for Kidney Stone Disease.

INTRODUCTION: Clinical guidelines recommend monitoring for metabolic derangements while on preventive pharmacologic therapy for kidney stone disease. The study objective was to compare the frequency of side effects among patients receiving alkali citrate, thiazides, and allopurinol. METHODS: Using claims data from working-age adults with kidney stone disease (2008-2019), we identified those with a new prescription for alkali citrate, thiazide, or allopurinol within 12 months after their index stone-related diagnosis or procedure. We fit multivariable logistic regression models, adjusting for cohort characteristics like comorbid illness and medication adherence, to estimate 2-year measured frequencies of claims-based outcomes of acute kidney injury, falls/hip fracture, gastritis, abnormal liver function tests/hepatitis, hypercalcemia, hyperglycemia/diabetes, hyperkalemia, hypokalemia, hyponatremia, and hypotension. RESULTS: Our cohort consisted of 1776 (34%), 2767 (53%), and 677 (13%) patients prescribed alkali citrate, thiazides, or allopurinol, respectively. Comparing unadjusted rates of incident diagnoses, thiazides compared to alkali citrate and allopurinol were associated with the highest rates of hypercalcemia (2.3% vs 1.5% and 1.0%, respectively, P = .04), hypokalemia (6% vs 3% and 2%, respectively, P < .01), and hyperglycemia/diabetes (17% vs 11% and 16%, respectively, P < .01). No other differences with the other outcomes were significant. In adjusted analyses, compared to alkali citrate, thiazides were associated with a higher odds of hypokalemia (OR=2.01, 95% CI 1.44-2.81) and hyperglycemia/diabetes (OR=1.52, 95% CI 1.26-1.83), while allopurinol was associated with a higher odds of hyperglycemia/diabetes (OR=1.34, 95% CI 1.02-1.75). CONCLUSIONS: These data provide evidence to support clinical guidelines that recommend periodic serum testing to assess for adverse effects from preventive pharmacologic therapy.

[Are thiazide diuretics ineffective with a glomerular filtration rate lower than 50 ml/min?] / Thiaziddiuretika unwirksam bei einer glomerulären Filtrationsrate kleiner als 50 ml/min?

Many treatment guidelines do not recommend the use of thiazide diuretics or thiazide-like diuretics in patients with impaired kidney function. The rationale is a presumed lack of efficacy of these diuretics in cases of a reduced glomerular filtration rate (GFR); however, this paradigm could not be verified in recent studies. Thiazide diuretics and thiazide-like diuretics are also effective in patients with substantially reduced GFR, which pertains to natriuresis, correction of volume overload and lowering of blood pressure; however, in patients with chronic kidney disease loop diuretics can control volume overload more rapidly. Particularly effective is the combination of loop diuretics with thiazide diuretics or thiazide-like diuretics in patients with markedly limited GFR. Therefore, thiazide diuretics and thiazide-like diuretics should also be prescribed even for patients with higher grade impairments of kidney function (chronic kidney disease in stages 3-5), except for anuric patients where they are ineffective.