Hyponatremia associated with long-term medication use in the elderly: an analysis in general practice

The risk of antidepressant-induced hyponatremia: A meta-analysis of antidepressant classes and compounds

BACKGROUND

Hyponatremia (hypoNa) is a potentially serious adverse event of antidepressant treatment. Previous research suggests the risk of drug-induced hyponatremia differs between antidepressants. This meta-analysis sought to determine the risk of antidepressant-induced hypoNa, stratified by different compounds and classes.

METHODS

A PRISMA-compliant systematic search of Web of Science and PubMed databases was performed from inception until Jan 5, 2023, for original studies reporting incidences or risks of hypoNa in adults using antidepressants. We modelled random-effects meta-analyses to compute overall event rates and odds ratios of any and clinically relevant hypoNa for each compound and class, and ran head-to-head comparisons based on hypoNa event rates. We conducted subgroup analyses for geriatric populations and sodium cut-off value. The study is registered with PROSPERO, CRD42021269801.

RESULTS

We included 39 studies (n = 8,175,111). Exposure to antidepressants was associated with significantly increased odds of hypoNa (k = 7 studies, OR = 3.160 (95%CI 1.911-5.225)). The highest event rates were found for SNRIs (7.44%), SSRIs (5.59%), and TCAs (2.66%); the lowest for mirtazapine (1.02%) and trazodone (0.89%). Compared to SSRIs, SNRIs were significantly more likely (k = 10, OR = 1.292 (1.120 - 1.491), p < 0.001) and mirtazapine significantly less likely (k = 9, OR = 0.607 (0.385 - 0.957), p = 0.032) to be associated with hypoNa.

CONCLUSION

Our meta-analysis demonstrated that, while no antidepressant can be considered completely risk-free, for hypoNa-prone patients mirtazapine should be considered the treatment of choice and SNRIs should be prescribed more cautiously than SSRIs and TCAs.

Who killed Bruce Lee? The hyponatraemia hypothesis

Bruce Lee brought attention to martial arts in the Western world and popularized the quote 'Be water, my friend'. Lee died at the age of 32 years in Hong Kong on 20 July 1973, under mysterious circumstances. The cause of death is unknown, although numerous hypotheses have been proposed, from assassination by gangsters to the more recent suggestion in 2018 that he died from heatstroke. The necropsy showed cerebral oedema. A prior episode was diagnosed as cerebral oedema 2 months earlier. We now propose, based on an analysis of publicly available information, that the cause of death was cerebral oedema due to hyponatraemia. In other words, we propose that the kidney's inability to excrete excess water killed Bruce Lee. In this regard, Lee had multiple risk factors for hyponatraemia that may have included high chronic fluid intake, factors that acutely increase thirst (marijuana) and factors that decrease the ability of the kidneys to excrete water by either promoting secretion of antidiuretic hormone (ADH) or interfering with water excretion mechanisms in kidney tubules: prescription drugs (diuretics, non-steroidal anti-inflammatory drugs, opioids, antiepileptic drugs), alcohol, chronic low solute intake, a past history of acute kidney injury and exercise.

Potentially inappropriate medications in older Chinese outpatients based on the Beers criteria and Chinese criteria

Objective: Polypharmacy increases the prevalence of potentially inappropriate drugs potentially inappropriate medications among older persons, lowering their quality of life. PIMs use can lead to higher mortality in older patients. This study aimed to compare the prevalence of PIMs in older Chinese outpatients according to the Beers criteria and the Chinese criteria and to analyze the risk factors. Second, we describe the differences between the two criteria, focusing on the inappropriate prescription of drugs in older outpatients.

Methods: In Chengdu, Southwest China, a cross-sectional study was undertaken using electronic medical data from 9 general hospitals s. Outpatients above the age of 60 who were treated in the Geriatrics Center of these medical institutions were included. The 2019 Beers criteria and the 2017 Chinese criteria were used to evaluate the PIM status of older outpatients, and binary logistic regression was used to identify potential risk factors for PIMs.

Results: There were 44,458 prescriptions from 2016 to 2018. The prevalence of PIMs among older outpatients was 30.05% (according to the Beers criteria) and 35.38% (according to the Chinese criteria), with statistical difference. Estazolam, hydrochlorothiazide and alprazolam were the top three PIMs in the Beers criteria, while the top three PIMs in the Chinese criteria were clopidogrel, estazolam and insulin. The prevalence of PIMs was associated with age, the number of diseases and the number of drugs. PIMs were shown to be more common in patients aged 70 and above, with more than 2 kinds of diseases and more than 4 kinds of drugs.

Conclusion: PIMs were shown to be common among older outpatients in China, according to this study. The detection rate of the Chinese criteria was higher than that of the Beers criteria.

A Retrospective Chart Review: The Prevalence of Hyponatremia Among Elderly Inpatients in a Tertiary Care Centre in Saudi Arabia

Introduction: Hyponatremia is commonly seen in inpatient care; however, the availability of data regarding the prevalence of hyponatremia in the elderly in Jeddah, Saudi Arabia is insufficient.

Objectives: The objective of this study is to estimate the prevalence of hyponatremia in a sample of older inpatients.

Materials and Methods: A retrospective chart review conducted in a tertiary care hospital, Jeddah, Saudi Arabia included all patients 60 years and older who were admitted to the internal medicine department between January 2017 and November 2020. Patients with hyponatremia were identified by looking through the hospital’s laboratory database of inpatients. Patients’ demographics, serum sodium level, medication history, and disease history were recorded and those with pseudohyponatremia were excluded.

Results: During the study period, 322 out of a total of 2,893 elderly patients admitted to the internal medicine department were diagnosed with hyponatremia (11.1%). Of these patients, 183 (56.8%) were female and 139 (43.2%) were male. Hyponatremia was more prevalent in patients with cardiovascular diseases (84.2%), followed by endocrine diseases (73.3%). The most prescribed medications for the studied hyponatremic patients were proton pump inhibitors (38.8%), diuretics (29.8%), angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (22.4%), all of which are commonly known to be associated with hyponatremia.

Conclusions: Hyponatremia has severe consequences if left untreated. Therefore, estimating the prevalence of this condition in the older population will direct more clinical attention to evaluate the serum sodium level on a regular basis. It is recommended that future studies focus on finding an association between hyponatremia and older patients with multi-drug usage as well as identifying the causes of hyponatremia.

Effects of Natural Reduced Water on Cognitive Function, Body Composition, and Psychological Function in Older Adults: Study Protocol for a Randomized Controlled Trial

Natural reduced water is natural water that contains active hydrogen and reduces oxidation. It is rare in the world, and in Japan, it is produced in the Hita area of Oita Prefecture (Hita Tenryosui water). Previous studies in humans have examined the effects of natural reduced water on diabetes, which is one of the known risks for dementia. Animal studies of natural reduced water have revealed anti-obesity and anti-anxiety effects. However, the effects of natural reduced water on cognitive function, body composition, and psychological function in humans are unknown. Therefore, we investigated the relationship between these items in elderly people who continuously consume natural reduced water. In this study, we recruited participants aged between 65 and 74 years. The participants were randomly and blindly assigned to a natural reduced water (Hita Tenryosui water) group or a control (tap water) group and drank 1 L of water daily for 6 months. Cognitive function, body composition, and psychological function were measured before and after the 6-month intervention period.

Increased Mortality in Elderly Patients Admitted with Hyponatremia: A Prospective Cohort Study

Hyponatremia is the most common electrolyte disorder, commonly affecting older hospitalized individuals; however, the literature is not clear regarding its effect on mortality. The aim of this 2-year observational prospective cohort study was to evaluate the mortality and re-admission rates, the clinical and laboratory characteristics and the causes of hyponatremia in patients older than 65 years admitted with a corrected serum sodium of 130 mEq/L or less in an internal medicine ward of a tertiary Greek university hospital. During the observation period, 138 patients (mean age 80.5 years, 36.2% male) fulfilled the inclusion criteria and were prospectively followed for 1 year after admission. Symptoms of hyponatremia were present in 59.4% of patients. Hypovolemia was the main sole cause of hyponatremia, but in about one third of patients, hyponatremia was multifactorial. Only a low proportion of patients (12.3%) fulfilled the criteria of the syndrome of inappropriate antidiuresis (SIAD) at admission according to the current guidelines. The re-admission rates at 3- and 12-months following discharge was 34.2% and 51.8%, respectively. Mortality during hospitalization was 17.4% and was higher compared to non-hyponatremic admitted older patients, while the total mortality at 1 year after admission was 28.3%, indicating that hyponatremia at admission is a marker of significant mortality during and after hospitalization in elderly patients.

Assocıatıons between mıld hyponatremıa and gerıatrıc syndromes ın outpatıent settıngs

PURPOSE

The impact of mild hyponatremia on geriatric syndromes is not clear. Our aim was to determine associations between mild hyponatremia and results of comprehensive geriatric assessment tools in outpatient settings.

METHODS

We reviewed medical records of 1255 consecutive outpatient elderly subjects and compared results of comprehensive geriatric assessment measures among patients with mild hyponatremia (serum Na⁺ 130-135 mEq/L) versus normonatremia (serum Na⁺ 136-145 mEq/L). The comprehensive geriatric assessment measures included the Basic and Instrumental Activities of Daily Living, Mini Mental State Examination, Geriatric Depression Score, Tinetti Mobility Test, the Timed Up&Go Test, the Mini Nutritional Assessment, the handgrip test, the Insomnia Severity Index, polypharmacy, recurrent falls, urinary incontinence, orthostatic hypotension, and nocturia.

RESULTS

Of the 1255 patients, 855 were female (68.1%), and the mean age was 73.7 ± 8.3 years. Mild hyponatremia was detected in 108 patients (8.6%). The median serum sodium was 140.5 [interquartile range (IQR) 138.4-141.8] versus 133.8 [IQR, 132.3-134.2] in normonatremia and mild hyponatremia groups, respectively (p < 0.001). The only significant difference for comorbidities between normonatremia and mild hyponatremia groups was the frequency of hypertension (66.9% versus 76.7%, respectively (p = 0.041). None of the comprehensive geriatric assessment tools conferred a significant association with mild hyponatremia. Of the 1061 subjects with available survival data, 96 (9.0%) deceased within 3-4 years of follow-up (p = 0.742). Hyponatremia as an independent variable did not have a significant effect on mortality in univariate logistic regression analysis (OR 1.13, 95% CI 0.55-2.33, p = 0.742).

CONCLUSION

Mild hyponatremia does not apparently affect results of geriatric assessments significantly. Whether particular causes of hyponatremia may have different impacts should be tested in further studies.

Prevalence of hyponatremia among older inpatients in a general hospital

PURPOSE

This study aimed to explore the incidence, clinical features, etiology, and mortality of hyponatremia in older inpatients and thus provide preliminary data for an epidemiological study.

METHODS

Hospitalized older patients diagnosed with hyponatremia at the First Medical Center of PLA General Hospital during January 2013-December 2016 were stratified by serum sodium concentrations into mild (130- < 135 mmol/L), moderate (125- < 130 mmol/L) and severe hyponatremia groups (< 125 mmol/L). Etiologies, medication histories, hospitalization times, and outcomes were analyzed.

RESULTS

During the indicated period, 4364 older patients with hyponatremia were hospitalized, including 2934 men and 1430 women with an average age of 84.6 ± 3.5 years (range 80-104 years). The prevalence of hyponatremia was 24.7%. An analysis of common primary diseases identified respiratory diseases as the most frequent (25.0%), followed by tumors (23.1%), cardiovascular diseases (19.9%), central nervous system diseases (8.9%), and orthopedic diseases (6.1%). PPIs (59.7%), loop diuretics (57.4%), potassium-preserving diuretics (29.5%), ACEIs/ARBs (20.0%), thiazide diuretics (12.5%), and NSAIDs (12.4%) were the drugs most commonly associated with hyponatremia. The in-hospital mortality rate was 11.7%. Aggravated hyponatremia led to a prolonged hospitalization time. Moreover, when compared with mild hyponatremia, moderate and severe hyponatremia were associated with significant increases in in-hospital mortality (ORs 1.89 and 2.66, respectively; 95% CIs 1.54-2.33 and 2.06-3.43, respectively; P < 0.01).

CONCLUSIONS

Hyponatremia is a common complication in hospitalized older patients and is caused mainly by respiratory diseases, tumors, and cardiovascular diseases. Given the correlation between the degree of hyponatremia and prognosis, the early and accurate identification and treatment of this condition can reduce the associated morbidity and mortality.

Association of Hyponatraemia and Antidepressant Drugs: A Pharmacovigilance-Pharmacodynamic Assessment Through an Analysis of the US Food and Drug Administration Adverse Event Reporting System (FAERS) Database

BACKGROUND

Hyponatraemia induced by antidepressant drugs is a rare but potentially life-threatening adverse reaction. Whether it is associated with all or only some antidepressant drugs is still unclear. This needs to be clarified to guide antidepressant therapies, especially in patients with electrolytic imbalances.

OBJECTIVES

The primary objective of this study was to quantify the strength of association between the use of different antidepressant drugs and hyponatraemia by using information reported to the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). The secondary objective was to investigate the putative relationship between different antidepressant pharmacological targets and the risks of hyponatraemia induced by antidepressant drugs using the 'pharmacovigilance-pharmacodynamic' method.

METHODS

We used the FAERS database to conduct a case/non-case analysis on spontaneous reports, focusing on events of hyponatraemia/syndrome of inappropriate antidiuretic hormone secretion (SIADH) reported in connection with the use of antidepressant drugs. Risk was expressed as a measure of disproportionality using the reporting odds ratio while adjusting for sex, age and concomitant medications associated with hyponatraemia/SIADH. We assessed to what extent the receptor-binding properties of antidepressant drugs could associate with the reporting odds ratios of hyponatraemia/SIADH of antidepressant drugs, building a linear regression model that included as independent variables the binding affinities (pKi) to the serotonin transporter, dopamine transporter, norepinephrine transporter, and serotonin 5-HT_2C, 5-HT_2A and 5-HT_1A, and α₁- and α₂-adrenergic receptors.

RESULTS

There were 2233 reports identified. The adjusted reporting odds ratio for the association between antidepressant drug use and hyponatraemia was 1.91 (95% confidence interval 1.83-2.00). The association was strongest for mirtazapine, followed by selective serotonin reuptake inhibitors, and lowest with serotonin-modulating antidepressant drugs. A significant linear correlation was found between the adjusted reporting odds ratios for hyponatraemia and pKi for the adrenergic receptors α₁ and α₂.

CONCLUSIONS

Hyponatraemia is reported at a disproportionately higher level with classes of antidepressant drugs (noradrenergic and specific serotonergic antidepressant [mirtazapine] and serotonin modulators [vortioxetine]) that are in general considered to have a better profile of tolerability in terms of hyponatraemia. With regard to the presented results, the risk of hyponatraemia with mirtazapine appears to be greater than what was reported in the literature; however, confounding by indication cannot be ruled out. Our pharmacovigilance-pharmacodynamic analysis also indicates that inhibition of the serotonin transporter may not be involved in the hyponatraemia linked to the use of antidepressant drugs.