Psychotropic drug-induced hyponatremia: results from a drug surveillance program-an update

Drug-induced hyponatremia in clinical care

PURPOSE

Over the last decades, advances in understanding of previously described associations have important implications for diagnosis and workup of hyponatremia. In addition, new drug groups potentially affecting sodium balance and water homeostasis have evolved. The aim of this review is to summarize current evidence on drug-induced hyponatremia in clinical care.

METHODS

We searched PubMed using the string "Inappropriate ADH Syndrome/chemically induced"[Mesh] OR "Inappropriate ADH Syndrome/diagnosis"[Mesh]) OR ("Hyponatremia/chemically induced"[Mesh] OR "Hyponatremia/diagnosis"[Mesh]), January 1st, 2008, to September 2nd 2024. In total 2003 articles were found and reviewed. Relevant articles referenced herein were subsequently traced backwards and also reviewed.

RESULTS

Drugs associated with hyponatremia, including selective serotonin reuptake inhibitors, antipsychotics, antiepileptic drugs and proton pump inhibitors, typically cause hyponatremia shortly after initiation of treatment. For thiazide diuretics, the number one culprit in drug-induced hyponatremia, the risk for hyponatremia is highest the first weeks after initiation and then gradually decreases to a stable but still increased level after around 3 months. Several drugs that promote a negative water balance such as loop diuretics, lithium and of sodium-glucose cotransporter-2 inhibitors appear to decrease the risk for hyponatremia. Treatment with immune checkpoint inhibitors is associated with an increased risk of hypophysitis and adrenalitis resulting in hyponatremia due to secondary and primary cortisol deficiency.

CONCLUSION

For most drugs associated with hyponatremia, including thiazides, the cause-effect relationship is tightly linked to newly initiated treatment. Further research is warranted to characterize the association between hyponatremia and newly developed drugs such as sodium-glucose cotransporter-2 inhibitors and immune checkpoint inhibitors.

Evaluation of hyponatremia among older adults exposed to selective serotonin reuptake inhibitors and thiazide diuretics

OBJECTIVE

Hyponatremia is a common electrolyte disorder among older adults that can cause serious adverse effects. The purpose of this study was to assess the risk of hyponatremia with the concurrent use of selective serotonin reuptake inhibitors (SSRIs) and thiazide diuretics in an older population.

METHODS

Two retrospective nested case-control studies were conducted with exposure to an SSRI or a thiazide diuretic. Persons of interest were those enrolled in Medicare and who received parts A, B, and D benefits from 2017 to 2019 and who were receiving either an SSRI or thiazide diuretic. Cases were individuals with a diagnosis of hyponatremia. Controls had no documented history of hyponatremia. A logistic regression was conducted to determine the odds of hyponatremia.

RESULTS

Of the 551,298 patients receiving a SSRIs, the mean age was 77.8 years (Standard Deviation (SD) ± 8.0 years), 69% were female, and 91.23% were classified as White. We identified 701,007 individuals receiving a thiazide diuretic, with a mean age of 77.1 years (SD ± 7.2 years), 60.2% female, and 82.72% White. The prevalence of hyponatremia was 10.4% in patients taking thiazides alone and 9.0% in those taking SSRIs alone. On the other hand, patients on both medications had a hyponatremia prevalence of approximately 13.0%. Among SSRI users, the adjusted odds ratio (OR) of hyponatremia with concomitant use of thiazide diuretics was 1.24 (95% Confidence Interval (CI): 1.22-1.26). For thiazide users, the adjusted OR of hyponatremia with exposure to SSRIs was 1.27 (95% CI:1.24-1.29).

CONCLUSION

The concurrent use of thiazide diuretics and SSRIs is associated with an increased risk of hyponatremia in older populations.

Vortioxetine-associated syndrome of inappropriate ADH secretion

This case report presents the first documented instance of vortioxetine-induced syndrome of inappropriate antidiuretic hormone secretion (SIADH) in India. Vortioxetine, a newer antidepressant, was prescribed to an elderly male in his 80s with major depressive disorder, in combination with mirtazapine. Despite initial improvement in mood, he developed hyponatraemia, a rare but serious side effect possibly linked to vortioxetine's serotonergic action. The patient exhibited symptoms such as giddiness and confusion, prompting the discontinuation of vortioxetine and initiation of corrective treatment. His condition improved, with sodium levels returning to normal while he was maintained on mirtazapine alone. This case underscores vortioxetine's potential to induce SIADH, highlighting the need for careful monitoring and the consideration of alternative antidepressants in vulnerable populations.

Psychotropic drug-induced adverse drug reactions in 462,661 psychiatric inpatients in relation to age: results from a German drug surveillance program from 1993-2016

BACKGROUND

Clinical practice suggests that older adults (i.e., ≥ 65 years of age) experience adverse drug reactions (ADRs) more often than younger patients (i.e., < 65 years of age). ADRs such as falls, extrapyramidal symptoms (EPS), metabolic disorders, sedation, and delirium are particularly worrisome and often associated with psychotropic drugs.

METHODS

This observational study investigated the risk for psychotropic drug-related ADRs in older (n = 99,099) and younger adults (n = 363,562) in psychiatric inpatients using data from the German pharmacovigilance program "Arzneimittelsicherheit in der Psychiatrie" (AMSP) from 1993-2016. The aim was to assess whether age influenced the risk of specific ADR types and if certain psychotropic drugs posed particular concerns.

RESULTS

The risk for ADRs did not differ between older and younger patients (relative risk 0.98, 95% confidence interval 0.92-1.05). However, older patients had a higher risk for delirium (2.35, 1.85-2.99), hyponatremia (3.74, 2.85-4.90), and orthostatic syncope (2.37, 1.72-3.26), as well as certain types of EPS, e.g., parkinsonism (1.89, 1.45-2.48) and Pisa-/metronome syndrome (3.61, 2.51-5.18). The risk for other ADRs, such as acute dystonia (0.20, 0.10-0.37), akathisia (0.47, 0.29-0.76), liver dysfunction (0.63, 0.48-0.82), weight gain (0.07, 0.04-0.14), sexual dysfunction (0.03, CI 0.00-0.25), and hyperprolactinemia/galactorrhea (0.05, 0.02-0.17) was significantly lower for older patients. Older patients treated with any type of antidepressant drug (1.33, 1.26-1.40)-especially selective serotonin reuptake inhibitors (1.57, 1.26-1.40) and selective serotonin-norepinephrine reuptake inhibitors (2.03, 1.80-2.29)-and lithium (1.74, 1.52-2.00) had a higher ADR risk than younger patients. Second-generation antipsychotic drugs had a lower (0.74, 0.71-0.77) and low-potency first-generation antipsychotic drugs a higher (1.19, 1.07-1.33) ADR risk in older patients. The risk for ADRs involving multiple drugs was higher in older patients (1.28, 1.22-1.34). ADRs in older patients were 6.4 times more likely to result in death.

CONCLUSIONS

Clinicians and pharmacists should be aware of the types of ADRs and high-risk drugs across age groups and provide appropriate monitoring. Pharmacovigilance is crucial in psychiatric patients of all ages and should not be neglected, even for drugs generally considered "safe".

Duloxetine-Induced Antidiuresis in Rats with Lithium-Induced Nephrogenic Diabetes Insipidus

Antidepressants, including duloxetine, are a significant cause of drug-induced hyponatremia, which can disrupt the continuation of medication. Tolvaptan is beneficial for correcting hyponatremia caused by the syndrome of inappropriate antidiuresis, but its impact on duloxetine-induced hyponatremia remains unknown. We used male Sprague-Dawley rats to examine the impact of duloxetine treatment on lithium-induced nephrogenic diabetes insipidus (Li-NDI) and to evaluate whether the results were reversed by co-treatment with tolvaptan. To induce Li-NDI, lithium chloride (40 mmol lithium/kg dry food) was administered for 2 weeks. Duloxetine (50 mg/kg/day) and tolvaptan (10 mg/kg/day) were also administered in food to assess their individual effects over the same period. At the end of each animal experiment, kidneys were harvested to measure levels of cAMP, vasopressin-2 receptor (V2R), cAMP-responsive element binding protein 1 (CREB-1), aquaporin-2 (AQP2), and prostaglandin E2 (PGE2). Water diuresis was induced in the Li-NDI rats, and duloxetine treatment reduced polyuria while increasing urine osmolality. Duloxetine treatment prevented the decrease in total AQP2, AQP2 phosphorylation at serine 256, and CREB-1 phosphorylation in Li-NDI rats. The V2R mRNA level was also reduced in Li-NDI rats and restored by duloxetine treatment. In the subsequent experiment, the decreased water diuresis in Li-NDI rats treated with duloxetine was reversed by co-treatment with tolvaptan. Tolvaptan co-treatment also reversed the changes in AQP2 protein and CREB-1 phosphorylation in the renal cortex and medulla. The decreased cAMP levels in Li-NDI rat kidneys were elevated by duloxetine treatment, and this elevation was reversed by co-treatment with tolvaptan. However, the elevated PGE2 levels in Li-NDI rat kidneys were not affected by either duloxetine alone or tolvaptan co-treatment. In conclusion, antidiuresis was induced by duloxetine in Li-NDI and reversed by tolvaptan co-treatment through alterations in the V2R-cAMP-AQP2 pathway. These findings could underlie the mechanism of duloxetine-induced hyponatremia and suggest the potential usefulness of tolvaptan in treating drug-induced hyponatremia.

Severe Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) Following the Initiation of Valbenazine for Tardive Dyskinesia: A Case Report

Hyponatremia, a common electrolyte disorder, usually has a benign clinical course. However, patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) can suffer unfavorable outcomes, including mortality. Atypical antipsychotics, which are among the drugs associated with SIADH, also cause tardive dyskinesia, a condition that physicians can now effectively manage with the recently approved agent - valbenazine. We herein report a case of severe hyponatremia due to SIADH in a 58-year-old man who developed hyponatremia-induced generalized seizures six weeks after valbenazine was added to his regimen to mitigate olanzapine-associated tardive dyskinesia. His electrolyte derangement and clinical course improved following prompt recognition and treatment of SIADH. The temporal association between the commencement of valbenazine and the onset of SIADH suggests a possible but previously unreported link between valbenazine and the development of SIADH. Awareness of this uncommon association is relevant to patient safety.

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.

The Role of Vortioxetine in the Treatment of Depressive Symptoms in General Hospital Psychiatry: A Case-Series and PRISMA-Compliant Systematic Review of the Literature

Depressive symptoms are a customary finding in hospitalized patients, particularly those who are undergoing long hospitalizations, underwent major surgical procedures or suffer from high levels of multimorbidity and frailty. The patients included in this case series shared high degrees of frailty-complexity and were evaluated within the ordinary consultation and liaison psychiatry service of the University Hospital in Pisa, Italy, from September 2021 to June 2023. Patients were administered at least one follow-up evaluation after a week and before discharge. To relate this case series to the extant literature, a comprehensive systematic review of vortioxetine safety and efficacy was performed. None of the six patients included developed serious safety issues, but one patient complained of mild-to-moderate nausea for some days after the vortioxetine introduction. Five out of six patients exhibited at least a slight clinical benefit as measured by the clinical global impression scale. Of the 858 entries screened via Scopus and Medline/PubMed, a total of 134 papers were included in our review. The present case series provides preliminary evidence for vortioxetine's safety in this healthcare domain. The literature reviewed in this paper seems to endorse a promising safety profile and a very peculiar efficacy niche for vortioxetine in consultation and liaison psychiatry.

Drug-drug interactions between COVID-19 therapeutics and psychotropic medications

INTRODUCTION

The coronavirus (COVID-19) pandemic has led to as well as exacerbated mental health disorders, leading to increased use of psychotropic medications. Co-administration of COVID-19 and psychotropic medications may result in drug-drug interactions (DDIs), that may compromise both the safety and efficacy of both medications.

AREAS COVERED

This review provides an update of the current evidence on DDIs between COVID-19 and psychotropic medications. The interactions are categorized into pharmacokinetic, pharmacodynamic, and other relevant types. A thorough literature search was conducted using electronic databases to identify relevant studies, and extract data to highlight potential DDIs, clinical implications, and management strategies.

EXPERT OPINION

Understanding and managing potential DDIs between COVID-19 and psychotropic medications is paramount to ensuring safe and effective treatment of patients with COVID-19 and mental illness. Awareness of the diverse spectrum of DDIs, vigilant monitoring, and judicious dose modifications, while choosing pharmacotherapeutic options with low risk of interaction whenever possible, are necessary. Ongoing and future investigations should continue to review the dynamic landscape of COVID-19 therapeutic modalities and their interactions with psychotropic medications.

An enigma of hypothyroidism and hyponatremia coexistence: a nationwide population-based retrospective study

INTRODUCTION

Hypothyroidism is a rare and possible cause of hyponatremia. However, the clinical epidemiology and risk of mortality (ROM) when they coexist still remain elusive.

OBJECTIVES

We assessed the epidemiology and ROM among index patients with coexisting hypothyroidism and hyponatremia via a national population database.

PATIENTS AND METHODS

This retrospective cohort study utilized Taiwan's National Health Insurance program database. Distributions of definite sociodemographic factors were analyzed. The annual incidence among the overall group and sex-subgroups was investigated. In addition, potential factors influencing the ROM were also evaluated.

RESULTS

Of 4,549,226 patients from 1998 to 2015, a total of 3,140 index patients with concurrent hypothyroidism and hyponatremia were analyzed. The incidence rate increased tenfold from 1998 to 2015; average annual incidence rate was 174. Among the total participants, 57.1% were women; mean age was 72.6 ± 14.7 years and 88.8% were aged > 55 years. Although average length of stay (LOS) was 13.1 ± 15.4 days, the mortality group had significantly longer LOS than that in the survival group (12.9 days vs 22.2 days). Old age, catastrophic illness, cardiac dysrhythmia, and low hospital hierarchy were independent predictors of hospital mortality. The optimal LOS cutoff value for ROM prediction was 16 days. Index patients with LOS > 16 days increased ROM by 2.3-fold.

CONCLUSIONS

Coexistent hypothyroidism and hyponatremia is rare, although the incidence increased gradually. Factors influencing the ROM, such as old age, underlying catastrophic status, cardiac dysrhythmia, hospital hierarchy, and LOS should be considered in clinical care.

[Antidepressant drugs-State of the art]

BACKGROUND

Due to their frequency, complications, and sequelae, depressive disorders are of great significance to patients, their environment, and society. They are considered the most frequent form of mental disturbances in old age. The use of antidepressant drugs (AD) represents a cornerstone of the treatment, which is always multidimensional.

OBJECTIVE

The classification, mechanism of action, efficacy and tolerability of AD are described. Furthermore, the practical treatment procedure as well as special aspects, such as treatment resistance and special features in old age are presented.

MATERIAL AND METHODS

Narrative review incorporating the most recent literature and the new edition of the national healthcare guidelines on unipolar depression.

RESULTS

In the past 20 years, a large number of so-called 2nd generation ADs have been approved worldwide with comparable efficacy but more favorable side effect profiles than conventional (tricyclic) substances. Almost all ADs act by enhancing monoaminergic, mostly serotonergic, neurotransmission. Other common features include a latency in the onset of action, moderate response rates, and potential efficacy on all core symptoms of depression. Side effects can include cardiovascular, metabolic, or sexual dysfunction, but these may significantly differ between drug classes. This enables individualized treatment taking age, individual risk factors, comorbidities and comedications into account.

CONCLUSION

With the correct interpretation of indications, knowledge of the risks, and consideration of the defined precautionary measures outlined here, treatment with AD is a safe and effective tool in the treatment of moderate and severe depression.

Identification of risk factors associated with hyponatremia in psychiatric patients: a case-control study

Background and aims

Prompt recognition and optimal management of hyponatremia helps the physician devise a better treatment plan to prevent future complications in patients. Hence this study aims to identify the risk factors associated with hyponatremia in psychiatric patients.

Methods

A case-control study was conducted among psychiatric inpatients in a tertiary care teaching hospital. Patients admitted from January 2013 to December 2017 were identified using ICD-10 code F01-F99. Patients with serum sodium levels < 135 mmol/L were considered to have hyponatremia and between 135-145 mmol/L as controls. Factors associated with hyponatremia were identified by multiple logistic regression, and the odds ratio (OR) was calculated.

Results

Based on the inclusion and exclusion criteria, 264 cases of hyponatremia and 253 matching controls were included in the study. The mean age of patients with hyponatremia was 56.4 ± 16.8 years compared to 39.6 ± 13.9 years in controls, and 65.7% of them were males. Seizure disorder (OR = 3.14, p = 0.047), bipolar disorder (OR = 6.03, p = 0.001), depression (OR = 4.78, p = 0.0005), use of quetiapine (OR = 2.11, p = 0.007) and insulin (OR = 3.53, p = 0.038) were independent risk factors associated with development of hyponatremia.

Conclusions

The chances of developing hyponatremia are increased in psychiatric patients with a seizure disorder, bipolar disorder, depression and using quetiapine or insulin. And they should be monitored carefully.

Pathophysiology of Drug-Induced Hyponatremia

Drug-induced hyponatremia caused by renal water retention is mainly due to syndrome of inappropriate antidiuresis (SIAD). SIAD can be grouped into syndrome of inappropriate antidiuretic hormone secretion (SIADH) and nephrogenic syndrome of inappropriate antidiuresis (NSIAD). The former is characterized by uncontrolled hypersecretion of arginine vasopressin (AVP), and the latter is produced by intrarenal activation for water reabsorption and characterized by suppressed plasma AVP levels. Desmopressin is useful for the treatment of diabetes insipidus because of its selective binding to vasopressin V2 receptor (V2R), but it can induce hyponatremia when prescribed for nocturnal polyuria in older patients. Oxytocin also acts as a V2R agonist and can produce hyponatremia when used to induce labor or abortion. In current clinical practice, psychotropic agents, anticancer chemotherapeutic agents, and thiazide diuretics are the major causes of drug-induced hyponatremia. Among these, vincristine and ifosfamide were associated with sustained plasma AVP levels and are thought to cause SIADH. However, others including antipsychotics, antidepressants, anticonvulsants, cyclophosphamide, and thiazide diuretics may induce hyponatremia by intrarenal mechanisms for aquaporin-2 (AQP2) upregulation, compatible with NSIAD. In these cases, plasma AVP levels are suppressed by negative feedback. In rat inner medullary collecting duct cells, haloperidol, sertraline, carbamazepine, and cyclophosphamide upregulated V2R mRNA and increased cAMP production in the absence of vasopressin. The resultant AQP2 upregulation was blocked by a V2R antagonist tolvaptan or protein kinase A (PKA) inhibitors, suggestive of the activation of V2R-cAMP-PKA signaling. Hydrochlorothiazide can also upregulate AQP2 in the collecting duct without vasopressin, either directly or via the prostaglandin E2 pathway. In brief, nephrogenic antidiuresis, or NSIAD, is the major mechanism for drug-induced hyponatremia. The associations between pharmacogenetic variants and drug-induced hyponatremia is an area of ongoing research.

Potential Use of Pharmacogenetics to Reduce Drug-Induced Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Syndrome of inappropriate antidiuretic hormone (SIADH) is a common cause of hyponatremia, and many cases represent adverse reactions to drugs that alter ion channel conductance within the peptidergic nerve terminals of the posterior pituitary. The frequency of drug-induced SIADH increases with age; as many as 20% of patients residing in nursing homes have serum sodium levels below 135 mEq/L. Mild hyponatremia is associated with cognitive changes, gait instability, and falls. Severe hyponatremia is associated with cerebral edema, seizures, permanent disability, and/or death. Although pharmacogenetic tests are now being deployed for some drugs capable of causing SIADH (e.g., antidepressants, antipsychotics, and opioid analgesics), the implementation of these tests has been based upon the prior known association of these drugs with other serious adverse drug reactions (e.g., electrocardiographic abnormalities). Work is needed in large observational cohorts to quantify the strength of association between pharmacogene variants and drug-induced SIADH so that decision support can be developed to identify patients at high risk.