Integrated metabolomics analysis reveals mechanistic insights into variability in blood pressure response to thiazide diuretics and beta blockers.

Hypertensive patients with a higher proportion of genetic West African ancestry (%GWAA) have better blood pressure (BP) response to thiazide diuretics (TDs) and worse response to ß-blockers (BBs) than those with lower %GWAA, associated with their lower plasma renin activity (PRA). TDs and BBs are suggested to reduce BP in the long term through vasodilation via incompletely understood mechanisms. This study aimed at identifying pathways underlying ancestral differences in PRA, which might reflect pathways underlying BP-lowering mechanisms of TDs and BBs. Among hypertensive participants enrolled in the Pharmacogenomics Evaluation of Antihypertensive Responses (PEAR) and PEAR-2 trials, we previously identified 8 metabolites associated with baseline PRA and 4 metabolic clusters (including 39 metabolites) that are different between those with GWAA <45% versus ≥45%. In the current study, using Ingenuity Pathway Analysis (IPA), we integrated these signals. Three overlapping metabolic signals within three significantly enriched pathways were identified as associated with both PRA and %GWAA: ceramide signaling, sphingosine 1- phosphate signaling, and endothelial nitric oxide synthase signaling. Literature indicates that the identified pathways are involved in the regulation of the Rho kinase cascade, production of the vasoactive agents nitric oxide, prostacyclin, thromboxane A2, and endothelin 1; the pathways proposed to underlie TD- and BB-induced vasodilatation. These findings may improve our understanding of the BP-lowering mechanisms of TDs and BBs. This might provide a possible step forward in personalizing antihypertensive therapy by identifying patients expected to have robust BP-lowering effects from these drugs.

Genetic Determinants of Thiazide-Induced Hyperuricemia, Hyperglycemia, and Urinary Electrolyte Disturbances - A Genome-Wide Evaluation of the UK Biobank.

Thiazide diuretics, widely used in hypertension, cause a variety of adverse reactions, including hyperglycemia, hyperuricemia, and electrolyte abnormalities. In this study, we aimed to identify genetic variants that interact with thiazide-use to increase the risk of these adverse reactions. Using UK Biobank data, we first performed genomewide variance quantitative trait locus (vQTL) analysis of ~ 6.2 million SNPs on 95,493 unrelated hypertensive White British participants (24,313 on self-reported bendroflumethiazide treatment at recruitment) for 2 blood (glucose and urate) and 2 urine (potassium and sodium) biomarkers. Second, we conducted direct gene-environment interaction (GEI) tests on the significant (P < 2.5 × 10-9) vQTLs, included a second UK Biobank cohort comprising 13,647 unrelated hypertensive White British participants (3,478 on thiazides other than bendroflumethiazide) and set significance at P = 0.05 divided by the number of vQTL SNPs tested for GEIs. The vQTL analysis identified eight statistically significant SNPs for blood glucose (5 SNPs) and serum urate (3 SNPs), with none being identified for the urinary biomarkers. Two of the SNPs (1 glucose SNP: CDKAL1 intron rs35612982, GEI P = 6.24 × 10-3; and 1 serum urate SNP: SLC2A9 intron rs938564, GEI P = 4.51 × 10-4) demonstrated significant GEI effects in the first, but not the second, cohort. Both genes are biologically plausible candidates, with the SLC2A9-mediated interaction having been previously reported. In conclusion, we used a two-stage approach to detect two biologically plausible genetic loci that can interact with thiazides to increase the risk of thiazide-associated biochemical abnormalities. Understanding how environmental exposures (including medications such as thiazides) and genetics interact, is an important step toward precision medicine and improved patient outcomes.

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.

Predicting sex differences in the effects of diuretics in renal epithelial transport during angiotensin II-induced hypertension.

Chronic angiotensin II (ANG II) infusion is an experimental model that induces hypertension in rodents. The natriuresis, diuresis, and blood pressure responses differ between males and females. This is perhaps not unexpected, given the rodent kidney, which plays a key role in blood pressure regulation, exhibits marked sex differences. Under normotensive conditions, compared with males, the female rat nephron exhibits lower Na+/H+ exchanger 3 (NHE3) activity along the proximal tubule but higher Na+ transporter activities along the distal segments. ANG II infusion-induced hypertension induces a pressure natriuretic response that reduces NHE3 activity and shifts Na+ transport capacity downstream. The goals of this study were to apply a computational model of epithelial transport along a rat nephron 1) to understand how a 14-day ANG II infusion impacts segmental electrolyte transport in male and female rat nephrons and 2) to identify and explain any sex differences in the effects of loop diuretics, thiazide diuretics, and K+-sparing diuretics. Model simulations suggest that the NHE3 downregulation in the proximal tubule is a major contributor to natriuresis and diuresis in hypertension, with the effects stronger in males. All three diuretics are predicted to induce stronger natriuretic and diuretic effects under hypertension compared with normotension, with relative increases in sodium excretion higher in hypertensive females than in males. The stronger natriuretic responses can be explained by the downstream shift of Na+ transport load in hypertension and by the larger distal transport load in females, both of which limit the ability of the distal segments to further elevate their Na+ transport.NEW & NOTEWORTHY Sex differences in the prevalence of hypertension are found in human and animal models. The kidney, which regulates blood pressure, exhibits sex differences in morphology, hemodynamics, and membrane transporter distributions. This computational modeling study provides insights into how the sexually dimorphic responses to a 14-day angiotensin II infusion differentially impact segmental electrolyte transport in rats. Simulations of diuretic administration explain how the natriuretic and diuretic effects differ between normotension and hypertension and between the sexes.

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.

Preventive Pharmacological Therapy and Risk of Recurrent Urinary Stone Disease.

BACKGROUND: Urinary stone disease is a prevalent condition associated with a high recurrence risk. Preventive pharmacological therapy has been proposed to reduce recurrent stone episodes. However, limited evidence exists regarding its effectiveness, contributing to its underutilization by physicians. This study aimed to evaluate the association between preventive pharmacological therapy (thiazide diuretics, alkali therapy, and uric acid-lowering medications) and clinically significant urinary stone disease recurrence. METHODS: Using data from the Veterans Health Administration, adults with an index episode of urinary stone disease from 2012 through 2019 and at least one urinary abnormality (hypercalciuria, hypocitraturia, or hyperuricosuria) on 24-hour urine collection were included. The primary outcome was a composite variable representing recurrent stone events that resulted in emergency department visits, hospitalizations, or surgery for urinary stone disease. Cox proportional hazards regression was performed to estimate the association between preventive pharmacological therapy use and recurrent urinary stone disease while adjusting for relevant baseline patient characteristics. RESULTS: Among the cohort of patients with urinary abnormalities ( n =5637), treatment with preventive pharmacological therapy was associated with a significant 19% lower risk of recurrent urinary stone disease during the 12-36-month period after the initial urine collection (hazard ratio, 0.81; 95% confidence interval, 0.65 to 1.00; P = 0.0496). However, the effectiveness of preventive pharmacological therapy diminished over longer follow-up periods (12-48 and 12-60 months after the urine collection) and did not reach statistical significance. When examining specific urinary abnormalities, only alkali therapy for hypocitraturia was associated with a significant 26% lower recurrence risk within the 12-36-month timeframe (hazard ratio, 0.74; 95% confidence interval, 0.56 to 0.97; P = 0.03). CONCLUSIONS: When considering all urinary abnormalities together, this study demonstrates that the use of preventive pharmacological therapy is associated with a lower risk of clinically significant recurrent episodes of urinary stone disease in the 12-36 month timeframe after urine collection, although only the association with the use of alkali therapy for hypocitraturia was significant when individual abnormalities were examined.

Risk of gout flare after medication: prescription symmetry sequence analysis.

OBJECTIVES: The research aimed to study the following questions: (1) five well-known gout-related medications were selected to test the validity of the prescription symmetry sequence analysis in Taiwan; (2) four exploratory medications were selected to test their relation to gout flares. METHODS: We utilized the 2003-2017 dataset of the Taiwan National Health Insurance Program containing all claims data with 2 million beneficiaries as a data source. In order to explore the temporal association, we designed a scenario of medication-induced gout flares. Nine medications were selected as the index agent, including aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol, pyrazinamide, metformin, pioglitazone, fenofibrate, and losartan. The gout flare was defined as subjects with use of the marker agent for treatment of gout flares. The observation-window period between initiation of the index agent and initiation of the marker agent was 1 year. Subjects who used an index agent and a marker agent on the same day were excluded. The prescription symmetry sequence analysis was carried out to compare the observed number of persons who took an index agent prior to starting a marker agent with the observed number of persons who took a marker agent before starting an index agent. The adjusted sequence ratio (adjusted SR) with 95% confidence interval was applied to estimate the relation between an index agent and the marker agent. RESULTS: Among five medications including aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol, and pyrazinamide, the adjusted sequence ratio ranged from 1.15 to 3.35 and all reached statistical significance. Fenofibrate use and losartan use were associated with a lower probability of gout flares, with reaching statistical significance (adjusted SR = 0.60 for fenofibrate and adjusted SR = 0.92 for losartan). Metformin use was associated with a greater probability of gout flares, with reaching statistical significance (adjusted SR = 1.14). Pioglitazone use did not reach statistical significance. CONCLUSION: Based on the confirmatory analysis including five well-known gout-related medications, this study supports that the prescription symmetry sequence analysis can be used to detect an adverse drug event associated with one potential offending agent. The exposure to fenofibrate or losartan might be a protective factor against gout flares. Metformin use could be associated with a greater probability of gout flares, but this finding should be validated by other studies. KEY POINTS: • What is already known about this subject? 1. The prescription symmetry sequence analysis is a useful method for detecting an adverse drug reaction associated with one potential offending drug. 2. Numerous medications are found to induce gout flares. • What does this study add? 1. The prescription symmetry sequence analysis supports the evidence that aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol and pyrazinamide are associated with a greater probability of gout flares. 2. The exposure to fenofibrate or losartan might be a protective factor against gout flares. 3. Metformin use could be associated with a greater probability of gout flares. • How might this impact on clinical practice or future developments? 1. Clinicians should always consider the possibility of medication-induced gout flares. If gout flares develop, discontinuation of risky medications is the first step. Then prescribing cascades can be eliminated.

Comparative estimation of the effects of antihypertensive medications on schizophrenia occurrence: a multinational observational cohort study.

BACKGROUND: The association between antihypertensive medication and schizophrenia has received increasing attention; however, evidence of the impact of antihypertensive medication on subsequent schizophrenia based on large-scale observational studies is limited. We aimed to compare the schizophrenia risk in large claims-based US and Korea cohort of patients with hypertension using angiotensin-converting enzyme (ACE) inhibitors versus those using angiotensin receptor blockers (ARBs) or thiazide diuretics. METHODS: Adults aged 18 years who were newly diagnosed with hypertension and received ACE inhibitors, ARBs, or thiazide diuretics as first-line antihypertensive medications were included. The study population was sub-grouped based on age (> 45 years). The comparison groups were matched using a large-scale propensity score (PS)-matching algorithm. The primary endpoint was incidence of schizophrenia. RESULTS: 5,907,522; 2,923,423; and 1,971,549 patients used ACE inhibitors, ARBs, and thiazide diuretics, respectively. After PS matching, the risk of schizophrenia was not significantly different among the groups (ACE inhibitor vs. ARB: summary hazard ratio [HR] 1.15 [95% confidence interval, CI, 0.99-1.33]; ACE inhibitor vs. thiazide diuretics: summary HR 0.91 [95% CI, 0.78-1.07]). In the older subgroup, there was no significant difference between ACE inhibitors and thiazide diuretics (summary HR, 0.91 [95% CI, 0.71-1.16]). The risk for schizophrenia was significantly higher in the ACE inhibitor group than in the ARB group (summary HR, 1.23 [95% CI, 1.05-1.43]). CONCLUSIONS: The risk of schizophrenia was not significantly different between the ACE inhibitor vs. ARB and ACE inhibitor vs. thiazide diuretic groups. Further investigations are needed to determine the risk of schizophrenia associated with antihypertensive drugs, especially in people aged > 45 years.

[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.

Role of Diuretics in Cardiovascular Events and Mortality in Systolic Blood Pressure Intervention Trial: A Post Hoc Analysis.

BACKGROUND: In a post hoc analysis, we examined whether postrandomization diuretics use can explain and/or mediate the beneficial effects of intensive systolic BP lowering on cardiovascular disease and all-cause mortality in the Systolic Blood Pressure Intervention Trial (SPRINT). METHODS: SPRINT was a randomized, controlled trial of 9361 participants comparing the effects of intensive (systolic BP target <120 mm Hg) versus standard (systolic BP target <140 mm Hg) BP control on a primary composite cardiovascular end point in participants aged 50 years or older with systolic BP of 130-180 mm Hg. In time-varying multivariable Cox analyses, we assessed hazard ratios (HRs) of cardiovascular end points and all-cause mortality in participants on thiazide type, loop and/or potassium (K) sparing, or no diuretics. We also conducted mediation analysis to formally assess the role of diuretics in the effects of intensive systolic BP lowering. RESULTS: At baseline, diuretics were prescribed in 46% and 48% of participants in standard and intensive systolic BP-lowering groups, respectively, and in 46% and 74% in the corresponding groups during the trial. The lower risk of cardiovascular end points in the intensive group (HR, 0.75; 95% confidence interval [CI], 0.64 to 0.89) persisted after adjustment for postrandomization time-varying diuretics use (HR, 0.74; 95% CI, 0.62 to 0.89). Across the entire study population, time-varying diuretics use was not associated with cardiovascular end points (compared with no diuretics, HR for thiazide type, 0.89; 95% CI, 0.73 to 1.10, and loop/K sparing, 1.29; 95% CI, 0.97 to 1.73). However, thiazide-type diuretics were associated with lower risk of cardiovascular end points in the intensive (HR, 0.62; 95% CI, 0.46 to 0.85) but not in the standard (HR, 1.07; 95% CI, 0.82 to 1.39) group. In mediation analysis, HRs for total effect, direct effect (not mediated through diuretics use), and indirect effect (mediated through diuretics) of the intervention on cardiovascular end points were 0.66 (95% CI, 0.54 to 0.79), 0.67 (95% CI, 0.54 to 0.81), and 0.98 (95% CI, 0.88 to 1.10), respectively. The results were largely similar for all-cause mortality. CONCLUSIONS: The favorable effects of intensive systolic BP lowering on cardiovascular end points and all-cause mortality in SPRINT were independent of and not mediated by time-varying diuretics use. However, thiazide-type diuretics use associated with benefit if intensive systolic BP lowering was targeted.

Sex differences in clinical characteristics and outcomes in the CLOROTIC (combining loop with thiazide diuretics for decompensated heart failure) trial.

AIMS: The addition of hydrochlorothiazide (HCTZ) to furosemide improved the diuretic response in patients with acute heart failure (AHF) in the CLOROTIC trial. Our aim was to evaluate if there were differences in clinical characteristics and outcomes according to sex. METHODS: This is a post-hoc analysis of the CLOROTIC trial, including 230 patients with AHF randomized to receive HCTZ or placebo in addition to an intravenous furosemide regimen. The primary and secondary outcomes included changes in weight and patient-reported dyspnoea 72 and 96 h after randomization, metrics of diuretic response and mortality/rehospitalizations at 30 and 90 days. The influence of sex on primary, secondary and safety outcomes was evaluated. RESULTS: One hundred and eleven (48%) women were included in the study. Women were older and had higher values of left ventricular ejection fraction. Men had more ischemic cardiomyopathy and chronic obstructive pulmonary disease and higher values of natriuretic peptides. The addition of HCTZ to furosemide was associated to a greatest weight loss at 72/96 h, better metrics of diuretic response and higher 24-h diuresis compared to placebo without significant differences according to sex (all p-values for interaction were not significant). Worsening renal function occurred more frequently in women (OR [95%CI]: 8.68 [3.41-24.63]) than men (OR [95%CI]: 2.5 [0.99-4.87]), p = 0.027. There were no differences in mortality or rehospitalizations at 30/90 days. CONCLUSION: Adding HCTZ to intravenous furosemide is an effective strategy to improve diuretic response in AHF with no difference according to sex, but worsening renal function was more frequent in women. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov: NCT01647932; EudraCT Number: 2013-001852-36.

Thiazide Diuretics and Risk of Colorectal Cancer: A Population-Based Cohort Study.

Evidence from clinical trials and observational studies on the association between thiazide diuretics and colorectal cancer risk is conflicting. We aimed to determine whether thiazide diuretics are associated with an increased colorectal cancer risk compared with dihydropyridine calcium channel blockers (dCCBs). A population-based, new-user cohort was assembled using the UK Clinical Practice Research Datalink. Between 1990-2018, we compared thiazide diuretic initiators with dCCB initiators and estimated hazard ratios (HR) with 95% confidence intervals (CIs) of colorectal cancer using Cox proportional hazard models. Models were weighted using standardized morbidity ratio weights generated from calendar time-specific propensity scores. The cohort included 377,760 thiazide diuretic initiators and 364,300 dCCB initiators, generating 3,619,883 person-years of follow-up. Compared with dCCBs, thiazide diuretics were not associated with colorectal cancer (weighted HR = 0.97, 95% CI: 0.90, 1.04). Secondary analyses yielded similar results, although an increased risk was observed among patients with inflammatory bowel disease (weighted HR = 2.45, 95% CI: 1.13, 5.35) and potentially polyps (weighted HR = 1.46, 95% CI: 0.93, 2.30). Compared with dCCBs, thiazide diuretics were not associated with an overall increased colorectal cancer risk. While these findings provide some reassurance, research is needed to corroborate the elevated risks observed among patients with inflammatory bowel disease and history of polyps.

Use trends of chlorthalidone and hydrochlorothiazide among United States adults with hypertension: National Health and Nutrition Examination Survey 2009-2018.

OBJECTIVES: To estimate the national prevalence of chlorthalidone and hydrochlorothiazide use among adults diagnosed with hypertension by sociodemographic subgroup, healthcare access status, and clinical factors. METHODS: Data was extracted from the National Health and Nutrition Examination Survey for 2009-2010 through 2017-2018 survey waves. Patients at least 20 years old, diagnosed with hypertension, and on hydrochlorothiazide or chlorthalidone were included. Uni-variable logistic regression models estimated the odds of being on chlorthalidone compared with hydrochlorothiazide use by sociodemographic and clinical factors. Analyses were adjusted for multi-stage complex survey design and are nationally representative. RESULTS: Two thousand five hundred and eighty-five participants were included with 95.2% participants using hydrochlorothiazide and 4.8% using chlorthalidone. Participants over 65 years were more likely to be on chlorthalidone compared with younger counterparts [odds ratio (OR) 1.8; 95% confidence interval (CI) 1.12-2.88]. Participants with hypokalemia (OR 2.62; 95% CI 1.56-4.42) or hyponatremia [OR 2.298; 95% CI 1.23-4.30) were more likely to be using chlorthalidone compared with patients with normal levels. CONCLUSION: Chlorthalidone, a potent and effective first-line antihypertensive agent and thoroughly studied thiazide diuretic with substantial cardiovascular benefits, continues to be underutilized in patients with hypertension. Findings demonstrated that individuals receiving chlorthalidone were more likely to be 65 years or older and to experience hyponatremia or hypokalemia. Sociodemographic factors, healthcare access and use, clinical factors, and medical conditions did not appear to sway the choice in thiazide diuretic use.

Cumulative Incidence of Thiazide-Induced Hyponatremia : A Population-Based Cohort Study.

BACKGROUND: According to drug labels, the frequency of thiazide-induced hyponatremia is unknown or uncommon to very rare (that is, <1 in 10 000 to <1 in 100), but the exact burden remains unclear. OBJECTIVE: To estimate the increase in the cumulative incidence of hyponatremia using thiazide diuretics compared with nonthiazide antihypertensive drugs in routine clinical practice. DESIGN: Population and register-based cohort study using target trial emulation. SETTING: Denmark, 1 January 2014 to 31 October 2018. PARTICIPANTS: Two target trials were emulated among persons aged 40 years or older who had no recent prescription for any antihypertensive drug, had no previous hyponatremia, and were eligible for the studied antihypertensive treatments. The first target trial emulation compared new use of bendroflumethiazide (BFZ) versus a calcium-channel blocker (CCB). The second target trial emulation compared new use of hydrochlorothiazide plus a renin-angiotensin system inhibitor (HCTZ-RASi; that is, combination pill) versus a RASi alone. MEASUREMENTS: Two-year cumulative incidences of sodium levels less than 130 mmol/L using stabilized inverse probability of treatment-weighted survival curves. RESULTS: The study compared 37 786 new users of BFZ with 44 963 of a CCB and 11 943 new users of HCTZ-RASi with 85 784 of a RASi. The 2-year cumulative incidences of hyponatremia were 3.83% for BFZ and 3.51% for HCTZ-RASi. The risk differences were 1.35% (95% CI, 1.04% to 1.66%) between BFZ and CCB and 1.38% (CI, 1.01% to 1.75%) between HCTZ-RASi and RASi; risk differences were higher with older age and higher comorbidity burden. The respective hazard ratios were 3.56 (CI, 2.76 to 4.60) and 4.25 (CI, 3.23 to 5.59) during the first 30 days since treatment initiation and 1.26 (CI, 1.09 to 1.46) and 1.29 (CI, 1.05 to 1.58) after 1 year. LIMITATION: The study assumed that filled prescriptions equaled drug use, and residual confounding is likely. CONCLUSION: Treatment initiation with thiazide diuretics suggests a more substantial excess risk for hyponatremia, particularly during the first months of treatment, than indicated by drug labeling. PRIMARY FUNDING SOURCE: Independent Research Fund Denmark.