Electrolyte disorders associated with the use of anticancer drugs

Hyponatremia in geriatric patients

Hyponatremia is the most frequent electrolyte imbalance in geriatric medicine. Causes of hyponatremia were retrospectively analyzed in all in-patients treated in 2016 (N = 2267, 1564 women, 703 men, mean age ± standard deviation 81.9 ± 7.6 years). Any form of hyponatremia on admission, during the stay or on discharge was noted in 308 patients (13.6%, 231 women, 77 men; mean age ± standard deviation 83.1 ± 7.3 years, p = 0.009 vs. age of all patients). Women had a higher probability of developing hyponatremia compared to men (p = 0.019), 131 patients were hypovolemic, and dyspnea as an indicator of hypervolemia was noted in 71 patients.Only 12 patients suffering from hyponatremia (3.9%) did not receive any of the potentially sodium-lowering drugs assessed (diuretics, angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, antidepressants, neuroleptics, nonsteroidal antirheumatics, carbamazepine, oxcarbazepine). The median number of drugs per patient potentially lowering the plasma sodium level was 3 and the maximum number was 7.Hypovolemic hyponatremia and the syndrome of inadequate antidiuretic hormone secretion were the most important causes of hyponatremia. Adverse drug effects were the main origins of both conditions. In patients with hyponatremia the drug load influencing plasma sodium level should be minimized, thiazide diuretics should be avoided and older individuals should receive a diet with sufficient salt content.

Electrolyte disorders induced by six multikinase inhibitors therapy for renal cell carcinoma: a large-scale pharmacovigilance analysis

To provide evidence for optimization of multi-kinase inhibitors (MKIs) use in the clinic, we use the public database to describe and evaluate electrolyte disorders (EDs) related to various MKIs treated for renal cell carcinoma. We analyzed spontaneous reports submitted to the Food and Drug Administration Adverse Events Reporting System (FAERS) in an observational and retrospective manner. Selecting electrolyte disorders' adverse events to multikinase inhibitors (axitinib, cabozantinib, lenvatinib, pazopanib, sunitinib, and sorafenib). We used Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and multi-item gamma Poisson shrinker (MGPS) algorithms to analyze suspected adverse reactions of electrolyte disorders induced by MKIs (which were treated for renal cell carcinoma) between January 2004 and December 2022. As of December 2022, 2772 MKIs (which were treated for renal cell carcinoma) ICSRs were related to electrolyte disorders AEs. In general, there were more AEs cases in males, except lenvatinib and 71.8% of the cases were submitted from North America. ICSRs in this study, the age group most frequently affected by electrolyte disorders AEs was individuals aged 45-64 years for axitinib, cabozantinib, pazopanib, and sunitinib, whereas electrolyte disorders AEs were more common in older patients (65-74 years) for sorafenib and lenvatinib. For all EDs documented in ICSRs (excluding missing data), the most common adverse outcome was hospitalization(1429/2674, 53.4%), and the most serious outcome was death/life-threat(281/2674, 10.5%). The prevalence of mortality was highest for sunitinib-related EDs (145/616, 23.5%), excluding missing data (n = 68), followed by cabozantinib-related EDs (20/237, 8.4%), excluding missing data (n = 1). The distribution of time-to-onset of Each drug-related ICSRs was not all the same, and the difference was statistically significant (P = 0.001). With the criteria of ROR, the six MKIs were all significantly associated with electrolyte disorders AEs, the strongest association was the association between cabozantinib and hypermagnesaemia. MKIs have been reported to have significant electrolyte disorders AEs. Patients and physicians need to recognize and monitor these potentially fatal adverse events.

A Conspectus of Euvolemic Hyponatremia, Its Various Etiologies, and Treatment Modalities: A Comprehensive Review of the Literature

Hyponatremia is the most prevalent electrolyte imbalance encountered among hospitalized patients, athletes, the elderly, patients with chronic ailments, postoperative patients, and a few asymptomatic individuals. Clinical manifestations of hyponatremia can be diverse, with characteristic neurological symptoms. Depending on in-depth medical history, physical examination (including volume status assessment), laboratory investigation, and drug history, patients can be classified broadly as undergoing hypervolemic, euvolemic, or hypovolemic hyponatremia. However, patients with hypervolemic hyponatremia often present with distinctive signs such as edema or ascites, and the clinical presentation of hypovolemic and euvolemic hyponatremia poses significant challenges for clinicians. The convolution in clinical manifestations of patients is due to the varied etiologies of euvolemic hyponatremia, such as syndrome of inappropriate antidiuretic hormone secretion (SIADH), adrenocortical insufficiency, hypothyroidism, psychogenic polydipsia, different classes of drugs (chemotherapeutics, antipsychotics, antidepressants), endurance exercise events, and reset osmostat syndrome (ROS). The management of hyponatremia depends on the rate of hyponatremia onset, duration, severity of symptoms, levels of serum sodium, and underlying comorbidities. Over the last decade, the clinical understanding of hyponatremia has been scattered due to the introduction of innovative laboratory markers and new drugs. This article will be a conspectus of all the recent advancements in the field of diagnosis, investigations, management, and associations of hyponatremia, along with traditional clinical practices. Subsequently, a holistic overview has been laid out for the clinicians to better understand and identify knowledge deficiencies on this topic.

Hypokalemia after rituximab administration in nephrotic syndrome: two case reports

Rituximab, a chimeric anti-CD20 monoclonal antibody, is an effective treatment for nephrotic syndrome. Hypokalemia is a rare adverse reaction among patients treated with rituximab although there have been extensive reports of acute and chronic adverse events with the administration of rituximab. We herein report two cases of symptomatic hypokalemia after intravenous rituximab administration in our center, to help health professionals consider the possibility of acute hypokalemia after rituximab administration, monitor potassium timely and develop an appropriate treatment plan.

A study to assess the health effects of an anticancer drug (cyclophosphamide) in zebrafish (Danio rerio): eco-toxicity of emerging contaminants

Cyclophosphamide (CP) is widely used for treating various kinds of cancer. Because of its high intake, metabolism and excretion, these anticancer medications have been detected in the aquatic environment. There is very limited data on the toxicity and effects of CP on aquatic organisms. The present study aims to assess the toxic effect of CP on certain oxidative stress biomarkers (superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase-GPx, glutathione-GSH, glutathione S-transferases-GST and lipid peroxidation-LPO), protein, glucose, metabolising enzymes (aspartate aminotransferase-AST, alanine aminotransferase-ALT), and ion-regulatory markers (sodium ions-Na⁺, potassium ions-K⁺, and chloride ions-Cl^-), and histology in the gills and liver of Danio rerio at environmentally relevant concentrations (10, 100 and 1000 ng L^-1). Exposure to CP for 42 days led to a significant decrease in SOD, CAT, GST, GPx and GSH levels in the gills and liver tissues of zebrafish. The level of lipid peroxidation in the gills and liver tissues of zebrafish was significantly increased compared to the control group. Chronic exposure significantly changes protein, glucose, AST, ALT, Na⁺, K⁺ and Cl^- biomarkers. Fish exposed to different levels of CP showed necrosis, inflammation, degeneration and hemorrhage in the gills and hepatic tissues. The observed changes in the studied tissue biomarkers were proportional to both dose and time. In conclusion, CP at environmentally relevant concentrations causes oxidative stress, energy demand, homeostasis disturbances, and enzyme and histological alterations in the vital tissues of zebrafish. These alterations were similar to the toxic effects reported in mammalian models.

The Onco-Nephrology Field: The Role of Personalized Chemotherapy to Prevent Kidney Damage

In recent years, the onco-nephrology field has acquired a relevant role in internal medicine due to the growing number of cases of renal dysfunction that have been observed in cancer patients. This clinical complication can be induced by the tumor itself (for example, due to obstructive phenomena affecting the excretory tract or by neoplastic dissemination) or by chemotherapy, as it is potentially nephrotoxic. Kidney damage can manifest as acute kidney injury or represent a worsening of pre-existing chronic kidney disease. In cancer patients, physicians should try to set preventive strategies to safeguard the renal function, avoiding the concomitant use of nephrotoxic drugs, personalizing the dose of chemotherapy according to the glomerular filtration rate (GFR) and using an appropriate hydration therapy in combination with nephroprotective compounds. To prevent renal dysfunction, a new possible tool useful in the field of onco-nephrology would be the development of a personalized algorithm for the patient based on body composition parameters, gender, nutritional status, GFR and genetic polymorphisms.

Acquired Disorders of Hypomagnesemia

Magnesium disorders are common in clinical practice and when present can manifest clinically as cardiovascular, neuromuscular, or other organ dysfunction. Hypomagnesemia is far more common than hypermagnesemia, which is largely seen in patients with reduced glomerular filtration rates receiving magnesium-containing medications. In addition to inherited disorders of magnesium handling, hypomagnesemia is also seen with excessive gastrointestinal or renal losses and due to medications such as amphotericin B, aminoglycosides, and cisplatin. Laboratory assessment of body magnesium stores largely relies on the measurement of serum magnesium levels that are a poor proxy for total body stores but does correlate with the development of symptoms. Replacement of magnesium can be challenging, with oral replacement strategies being generally more effective at slowly replacing body stores but intravenous replacement being more effective at treating the more life-threatening and severe cases of hypomagnesemia. We conducted a thorough review of the literature using PubMed (1970-2022) and the search terms magnesium, hypomagnesemia, drugs, medications, treatment, and therapy. In the absence of clear data on optimal management of hypomagnesemia, we have made recommendations on magnesium replacement based on our clinical experience.

Therapeutics in rheumatology and the kidney

The field of rheumatology has advanced significantly in recent years to provide rheumatologists with an extensive array of medications to combat rheumatic joint conditions. In contrast to an older era, when NSAIDs and other nephrotoxic agents were the mainstay of treatment, modern DMARDs vary considerably in their nephrotoxic potential and their use is not always precluded in populations with pre-existing chronic kidney disease (CKD). This review will explore in detail the safety and efficacy profiles of medications used to treat rheumatologic disease, specifically in the setting of CKD. Specifically, we discuss both traditional agents used, i.e. NSAIDs, CSs and conventional synthetic DMARDs, as well as novel biologic DMARDs and targeted synthetic DMARDs. Anti-gout prescribing in CKD is also reviewed. We aim to provide practical guidance to rheumatologists, nephrologists and general physicians when prescribing these medications in the setting of CKD.

Incidence and Determinants of Piperacillin/Tazobactam-Associated Hypokalemia: A Retrospective Study

Piperacillin/tazobactam (TZP) is a commonly used antibiotic for treating moderate-to-severe infections because of its broad-spectrum activity and recommendation as an alternative to carbapenem. TZP-associated severe hypokalemia has been consistently reported; however, related studies are very rare. This study aimed to evaluate the incidence and risk factors of TZP-associated hypokalemia (TAH). A retrospective cohort study was conducted on hospitalized adult patients who received TZP from 1 January 2015 to 31 December 2017 at a tertiary teaching hospital. Of the 713 patients, 13.9% had TAH. As a result of multivariate logistic regression analysis, older age (OR 1.03, 95% CI: 1.02−1.05, p < 0.001), female sex (OR 1.88, 95% CI: 1.18−3.00, p = 0.008), longer duration of TZP therapy (OR 1.08, 95% CI: 1.04−1.13, p < 0.001), and higher TZP daily dose (OR 1.10, 95% CI: 1.01−1.20, p = 0.049) were independently associated with TAH. In contrast, higher baseline serum potassium level (OR 0.13, 95% CI: 0.07−0.26, p < 0.001) was related to lower TAH. Furthermore, hypokalemia mostly occurred in the early days of TZP therapy (median onset time: 4 days). Thus, close monitoring of serum potassium levels, especially upon therapy initiation, is essential to prevent TAH.

Utility of a Laboratory Alert System for Detecting Adverse Drug Reactions in Hospitalised Patients: Hyponatremia and Rhabdomyolysis

Background—Adverse drug reactions (ADRs) are a public health issue, due to their great impact on morbidity, mortality, and economic cost. The use of automatized laboratory alerts could simplify greatly its detection.

Objectives—We aimed to evaluate the performance of a laboratory alerts system as a method for detecting ADRs, using hyponatremia and rhabdomyolysis as case studies.

Methods—This is a retrospective observational study conducted in 2019 during a 6-month period, including patients hospitalized at the Hospital Universitario de La Princesa. Patients were identified using altered laboratory parameters corresponding to the two signals: “rhabdomyolysis” (creatine phosphokinase >5 times the upper limit of normality (ULN): >1000 U/L for men and >900 U/L for women) and “hyponatremia” (<116 mEq/L) were detected. In cases where ADR was suspected, causality assessment was performed using the algorithm of the Spanish Pharmacovigilance System (SEFV).

Results—During the study period, 180 patients were studied for the “rhabdomyolysis” signal, 6 of them were found to have an ADR (3.3%). The sensitivity of the test was 60%, specificity 97%, and positive predictive value 41%. 28 patients were studied for the “hyponatremia” signal, and 11 patients were found to have an ADR (39.3%), with a sensitivity of 76.9%, a specificity of 93.3%, and a positive predictive value of 88.2%. We found no relationship between altered laboratory values and risk of ADR in any of the cases studied.

Conclusion—A pharmacovigilance program based on automatized laboratory signals could be an effective method to detect ADR. The study of the “hyponatremia” laboratory alert is more efficient than “rhabdomyolysis”. The evaluation of the hyponatremia alert allows the identification of 12 times more ADRs than the rhabdomyolysis alert, which means less time spent per alert evaluated to identify an ADR.

Potassium in Solid Cancers

Electrolyte disorders are a frequent finding in cancer patients. In the majority of cases the etiologies of such disorders are common to all cancer types (i.e. diuretic-induced hyponatremia or hypokalemia). Sometimes, electrolyte disorders are caused by paraneoplastic syndromes or are due to cancer therapy. Potassium is one of the most important electrolytes of the human body since it is involved in the regulation of muscle contraction, maintenance of the integrity of the skeleton, blood pressure and nerve transmission as well as in the normal function of cells. Potassium homeostasis is strictly regulated since the gap between the recommended daily dietary intake (120 mEq/day) and the levels stored in the extracellular fluid (around 70 mEq) is huge. Alterations of potassium homeostasis are frequent in cancer patients as well alterations in potassium channels, the transmembrane proteins that mediate potassium fluxes within the cells. The present chapter is focused on the clinical significance of potassium homeostasis and potassium channels in patients with solid tumors.

Safety Profile of Ibrutinib: An Analysis of the WHO Pharmacovigilance Database

As ibrutinib has become a standard of care in B-cell malignancies in monotherapy or in combination with other agents, definition of its safety profile appears essential. The aim of this study was to further characterize the safety profile of ibrutinib through the identification of potential safety signals in a large-scale pharmacovigilance database. All serious individual case safety reports (ICSRs) in patients aged ≥18 years involving ibrutinib suspected in the occurrence of serious adverse drug reactions or drug interacting from November 13th, 2013 to December 31st, 2020 were extracted from VigiBase, the World Health Organization global safety database. Disproportionality reporting was assessed using the information component (IC) and the proportional reporting ratio (PRR), with all other anticancer drugs used as the reference group. To mitigate the confounding of age, two subgroups were considered: patients aged<75 years and ≥75 years. A signal of disproportionate reporting (SDR) was defined if both IC and PRR were significant. A total of 16,196 ICSRs were included. The median age of patients was 72.9 years, 42.6% of ICSRs concerned patients aged ≥75 years, and 64.2% male patients. More than half (56.2%) of ICSRs resulted in hospitalization or prolonged hospitalization. Among 713 SDRs, 36 potential safety signals emerged in ibrutinib-treated patients, mainly ischemic heart diseases, pericarditis, uveitis, retinal disorders and fractures. All potential safety signals having arisen in this analysis may support patient care and monitoring of ongoing clinical trials. However, owing to the mandatory limitations of this study, our results need further confirmation using population-based studies.

Factors influencing the occurrence of electrolyte disorders in cancer patients

Objective:

The objective of this study was to determine the magnitude of electrolyte disorders and influencing factors among cancer patients in Southwest Ethiopia.

Methods:

Facility-based cross-sectional study was conducted in Jimma Medical Center (JMC). Eighty-four cancer patients admitted to JMC were recruited for this study. A structured questionnaire and serum electrolyte measurements were used for data collection. Bivariate and multiple logistic regression was employed to determine the association between electrolyte disorders and associated factors among admitted cancer patients. P value ⩽ 0.05 was used as a cut point to declare statistical significance.

Result:

The overall prevalence of electrolyte disorders was 60.7%. The presence or absence of comorbid diseases, age, body mass index (BMI), nutritional status, and current prescribed medication use were associated with electrolyte disorders. Younger patients had lower odds for electrolyte disorders (odds ratio (OR) = 0.128 (P value = 0.05) and OR = 0.08 (P value = 0.033)) for the first and the second quartile, respectively. Underweight patients had a threefold likelihood to develop electrolyte disorders (OR = 3.13 (P value = 0.043)) than having normal BMI. Compared with those in need of nutritional intervention, patients not in need of nutritional intervention had lower odds for the disorders (OR = 0.109 (P value = 0.006)). Medication had increased the likelihood of electrolyte disorders by 5.5 times than with no medication (P value = 0.023). Those who had comorbid disease had 10 times likely to develop electrolyte disorders than those who did not have comorbid diseases (P value = 0.004).

Conclusion:

Electrolyte disorders were prevalent in cancer patients. Age, BMI, nutritional condition, comorbid disease, and prescribed drugs were the predictors of electrolyte disorders in cancer patients. Authors recommend routine screening of electrolyte disorders in cancer patients and special emphasis on controlling and managing risk factors.

The prevalence and prognosis of hyponatraemia in non-Hodgkin lymphoma-associated hemophagocytic lymphohistiocytosis

Non-Hodgkin lymphoma associated hemophagocytic lymphohistiocytosis (NHL-HLH) in adult secondary HLH is a common and universally highly lethal critical disorder. Hyponatraemia is the most common electrolyte disorder in the critical illness setting and acts as a negative prognostic factor. The aim of our study was to evaluate the prognostic role of hyponatraemia among patients with NHL-HLH. The results showed that 81 (52.9%) patients had hyponatraemia. After a median follow up 47 (range 14-180) days, there were 72 (88.9%) cumulative deaths in hyponatraemia group while 50 (69.4%) in normonatremia group. After adjustment for confounders, multivariate analysis revealed that hyponatraemia was an independent prognostic factor for OS (HR:1.51, 95% CI: 1.03-2.20; p = 0.033). Restricted cubic spline confirmed a linear and positive association between serum sodium and the risk of mortality. Hyponatraemia is relatively frequent in NHL-HLH. As a readily available biomarker in clinical routine, it was a promising prognostic predictor for NHL-HLH.

Safety of low-volume PEG-asc bowel cleansing preparation for colonoscopy: identifying patients at risk for hypokalemia in a prospective cohort study

Background and study aims  The aim of bowel cleansing preparation should be high-quality results and conformance with safety standards. Previously, we reported that hypokalemia occurred in 23.6 % of patients after bowel preparation in a high-risk population on diuretics or hospitalized and referred for colonoscopy. Here we report on a prospective study in a non-selected colonoscopy cohort to identify patients at risk of developing hypokalemia before and after bowel cleansing with low-volume polyethylene glycol with ascorbic acid (PEG-asc). Patients and methods  From January 1 to July 31, 2016, we included all patients undergoing colonoscopy in our institution. Prevalences of hypokalemia before and after PEG-asc bowel cleansing for colonoscopy were calculated and risk factors for developing hypokalemia after PEG-asc bowel cleansing were identified. Results  In total, 2011 patients were included in the analysis. Of these, 0.8 % had hypokalemia before bowel cleansing with PEG-asc. After bowel preparation, 5.4 % developed hypokalemia. Of the patients, 281 were considered to have "high cardiac risk." The combination of "high cardiac risk" and hypokalemia was present in 1 % of the initial colonoscopy population. Female sex, colorectal cancer diagnosis, and thiazide use were found to be significant predictors for hypokalemia after use of PEG-asc. No arrhythmias or serious adverse events due to hypokalemia occurred. Conclusions  Physicians referring patients for colonoscopy should be aware that "high cardiac risk" patients and those on thiazide diuretics undergoing bowel cleansing for colonoscopy are a risk of developing post-cleansing hypokalemia but it remains to be determined whether their risk of developing life-threatening arrhythmias is truly increased.

An overview of diagnosis and management of drug-induced hypomagnesemia

Magnesium (Mg) is commonly addressed as the "forgotten ion" in medicine. Nonetheless, hypomagnesemia should be suspected in clinical practice in patients with relevant symptomatology and also be considered a predisposing factor for the development of other electrolyte disturbances. Furthermore, chronic hypomagnesemia has been associated with diabetes mellitus and cardiovascular disease. Hypomagnesemia as a consequence of drug therapy is relatively common, with the list of drugs inducing low serum Mg levels expanding. Culprit medications linked to hypomagnesemia include antibiotics (e.g. aminoglycosides, amphotericin B), diuretics, antineoplastic drugs (cisplatin and cetuximab), calcineurin inhibitors, and proton pump inhibitors. In recent years, the mechanisms of drug-induced hypomagnesemia have been unraveled through the discovery of key Mg transporters in the gut and kidney. This narrative review of available literature focuses on the pathogenetic mechanisms underlying drug-induced hypomagnesemia in order to increase the insight of clinicians toward early diagnosis and effective management.

Do the etiology of hyponatremia and serum sodium levels affect the length of hospital stay in geriatric patients with hyponatremia?

Background

Hyponatremia can lead to a prolonged hospital stay and increased morbidity and mortality rates in geriatric patients. This study aimed to evaluate the effects of hyponatremia etiology and serum sodium (Na) levels on hospitalisation time in geriatric patients hospitalised due to hyponatremia.

Methods

The demographic characteristics, laboratory data, etiology of hyponatremia, and length of hospital stay were retrospectively recorded for 132 patients over 65 years of age who were hospitalised for hyponatremia.

Results

Of the 132 patients, 90 were female (68.2%), and 42 were male (31.8%). The serum Na levels of 66 (50%) patients were <120 mmol/L, those of 64 (48.5%) patients were 120-129 mmol/L, and those of two (1.5%) patients were >130 mmol/L. One hundred nine (82.6%) patients had hypoosmolar hyponatremia, 14 (10.6%) patients had isoosmolar hyponatremia, and nine (6.8%) patients had hyperosmolar hyponatremia. Also, 19.7% of the patients were hypovolemic, 37.9% were euvolemic, and 42.4% were hypervolemic. Hyponatremia etiology was congestive heart failure in 38 (28.8%) patients, syndrome of inappropriate antidiuretic hormone in 29 (22.0%) patients, gastrointestinal fluid loss in 24 (18.2%) patients, renal pathologies in 20 (15.2%) patients, the presence of drugs in 20 (15.2%) patients, and hypocortisolemia in one (0.8%) patient. The mean length of hospital stay for the patients was five (1-60) days. There was no statistically significant difference between the lengths of hospital stay based on hyponatremia etiology and serum Na levels (p=0.861 and p=0.076). It was observed that the lengths of stay for patients who developed hyponatremia during their hospitalisation in various clinics were longer than those for patients who presented to the emergency department (p<0.001).

Conclusions

In this study, it was determined that the length of hospital stay did not change with the etiology of hyponatremia and serum Na level at the time of admission, but patients who developed hyponatremia during their hospitalisation had longer hospitalisation times.

A narrative review of progress in diagnosis and treatment of small cell lung cancer patients with hyponatremia

Small cell lung cancer (SCLC) is one of the malignant cancers of lung tumors, and hyponatremia, defined as serum sodium concentration (Na⁺) lower than 135 mmol/L, is the most common complication of solid tumors, with an incidence of up to 18.9% and a negative impact on quality of life in SCLC. As a prognostic index of SCLC, timely monitoring and correcting of hyponatremia is of great clinical significance for prolonging the survival period of patients. In the explore of new drugs for small cell lung cancer, it is necessary to include hyponatremia as an evaluation index in clinical studies. As the occurrence of hyponatremia is sometimes unavoidable owing to SCLC specific neurological characteristics, early monitoring to detect the presence of hyponatremia and timely correction are helpful to improve the prognosis of patients. There are many predisposing factors for hyponatremia, including heterotopia of antidiuretic hormone (ADH), use of platinum-based chemotherapy drugs, and intracranial metastasis, among others. Patients with small cell lung cancer are usually asymptomatic in the early stage, while it is of great significance to find a suitable clinical index to judge whether it is a malignant inducement or not. In the clinical setting, due to different electrolyte levels and therapeutic scheduling for the primary disease, an individualized plan is often made, mainly comprising water restriction, infusion, and medications. This review includes related clinical studies and describes the common symptoms and predisposing factors of hyponatremia in patients with SCLC, and their impact on quality of life and prognosis.

Hyponatremia in Patients with Hematologic Diseases

Hyponatremia is the most common electrolyte disorder in clinical practice and is associated with increased morbidity and mortality. It is frequently encountered in hematologic patients with either benign or malignant diseases. Several underlying mechanisms, such as hypovolemia, infections, toxins, renal, endocrine, cardiac, and liver disorders, as well as the use of certain drugs appear to be involved in the development or the persistence of hyponatremia. This review describes the pathophysiology of hyponatremia and discusses thoroughly the contributing factors and mechanisms that may be encountered specifically in patients with hematologic disorders. The involvement of the syndrome of inappropriate antidiuretic hormone (SIADH) secretion and renal salt wasting syndrome (RSWS) in the development of hyponatremia in such patients, as well as their differential diagnosis and management, are also presented. Furthermore, the distinction between true hyponatremia and pseudohyponatremia is explained. Finally, a practical algorithm for the evaluation of hyponatremia in hematologic patients, as well as the principles of hyponatremia management, are included in this review.

Anticancer Medications and Sodium Dysmetabolism

Therapeutic advances have revolutionised cancer treatment over the last two decades, but despite improved survival and outcomes, adverse effects to anticancer therapy such as dyselectrolytaemias do occur and need to be managed appropriately. This review explores essential aspects of sodium homeostasis in cancer with a focus on alterations arising from anticancer medications. Sodium and water balance are tightly regulated by close interplay of stimuli arising from hypothalamic osmoreceptors, arterial and atrial baroreceptors and the renal juxtaglomerular apparatus. This delicate balance can be disrupted by cancer itself, as well as the medications used to treat it. Some of the conventional chemotherapeutics, such as alkylating agents and platinum-based drugs, can cause hyponatraemia and, on rare occasions, hypernatraemia. Other conventional agents such as vinca alkaloids, as well as newer targeted cancer therapies including small molecule inhibitors and monoclonal antibodies, can cause hyponatraemia, usually as a result of inappropriate antidiuretic hormone secretion. Hyponatraemia can also sometimes occur secondarily to drug-induced hypocortisolism or salt-wasting syndromes. Another atypical but distinct mechanism for hyponatraemia is via pituitary dysfunction induced by immune checkpoint inhibitors. Hypernatraemia is uncommon and occasionally ensues as a result of drug-induced nephrogenic diabetes insipidus. Identification of the aetiology and appropriate management of these conditions, in addition to averting treatment-related problems, can be lifesaving in critical situations.

The Effect of Admission Serum Magnesium on the Acute Kidney Injury Among Patients with Malignancy

Purpose

This study aimed to explore the relationship between serum magnesium (Mg) levels and incidence of acute kidney injury (AKI) in patients with malignancy.

Patients and Methods

Hospitalized patients with malignancy between October 1, 2014 and September 30, 2015 in Zhongshan Hospital were recruited. All relevant data were extracted from the electronic database.

Results

All 99,845 patients were enrolled and 16,082 eligible patients were divided into three groups according to admission serum Mg levels in this study. Among them, 2383 (14.8%) cases were diagnosed as AKI. The incidence of AKI showed a V trend with the increase of serum Mg level. The effect of low serum Mg level on the onset of AKI seems to be greater than high serum Mg level. Patients with low serum Mg level spent a longer time in the hospital than those with normal serum Mg level and high serum Mg level. Further, multivariate logistic regression model was used to assess the importance of serum Mg level to influence AKI incidence. There was a higher AKI incidence in patients with magnesium level 0.66mmol/L or less (aOR=2.438, 95% CI=1.696, 3.505).

Conclusion

Low serum Mg level might be a independent risk factor for AKI in patients with malignancy. Appropriate clinical intervention for serum Mg disorder may contribute to decreasing the incidence of AKI and the possibility of poor outcomes in cancer patients.

Electrolyte Disorders Induced by Antineoplastic Drugs

The use of antineoplastic drugs has a central role in treatment of patients affected by cancer but is often associated with numerous electrolyte derangements which, in many cases, could represent life-threatening conditions. In fact, while several anti-cancer agents can interfere with kidney function leading to acute kidney injury, proteinuria, and hypertension, in many cases alterations of electrolyte tubular handling and water balance occur. This review summarizes the mechanisms underlying the disturbances of sodium, potassium, magnesium, calcium, and phosphate metabolism during anti-cancer treatment. Platinum compounds are associated with sodium, potassium, and magnesium derangements while alkylating agents and Vinca alkaloids with hyponatremia due to syndrome of inappropriate antidiuretic hormone secretion (SIADH). Novel anti-neoplastic agents, such as targeted therapies (monoclonal antibodies, tyrosine kinase inhibitors, immunomodulators, mammalian target of rapamycin), can induce SIADH-related hyponatremia and, less frequently, urinary sodium loss. The blockade of epidermal growth factor receptor (EGFR) by anti-EGFR antibodies can result in clinically significant magnesium and potassium losses. Finally, the tumor lysis syndrome is associated with hyperphosphatemia, hypocalcemia and hyperkalemia, all of which represent serious complications of chemotherapy. Thus, clinicians should be aware of these side effects of antineoplastic drugs, in order to set out preventive measures and start appropriate treatments.

Nephrotoxicity in cancer treatment: An overview

Anticancer drug nephrotoxicity is an important and increasing adverse drug event that limits the efficacy of cancer treatment. The kidney is an important elimination pathway for many antineoplastic drugs and their metabolites, which occurs by glomerular filtration and tubular secretion. Chemotherapeutic agents, both conventional cytotoxic agents and molecularly targeted agents, can affect any segment of the nephron including its microvasculature, leading to many clinical manifestations such as proteinuria, hypertension, electrolyte disturbances, glomerulopathy, acute and chronic interstitial nephritis, acute kidney injury and at times chronic kidney disease. The clinician should be alert to recognize several factors that may maximize renal dysfunction and contribute to the increased incidence of nephrotoxicity associated with these drugs, such as intravascular volume depletion, the associated use of nonchemotherapeutic nephrotoxic drugs (analgesics, antibiotics, proton pump inhibitors, and bone-targeted therapies), radiographic ionic contrast media or radiation therapy, urinary tract obstruction, and intrinsic renal disease. Identification of patients at higher risk for nephrotoxicity may allow the prevention or at least reduction in the development and severity of this adverse effect. Therefore, the aim of this brief review is to provide currently available evidences on oncologic drug-related nephrotoxicity.

Endocrinological Toxicity Secondary to Treatment of Gastroenteropancreatic Neuroendocrine Neoplasms (GEP-NENs)

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are increasingly recognized, characterized by prolonged survival even with metastatic disease. Their medical treatment is complex involving various specialties, necessitating awareness of treatment-related adverse effects (AEs). As GEP-NENs express somatostatin receptors (SSTRs), long-acting somatostatin analogs (SSAs) that are used for secretory syndrome and tumor control may lead to altered glucose metabolism. Everolimus and sunitinib are molecular targeted agents that affect glucose and lipid metabolism and may induce hypothyroidism or hypocalcemia, respectively. Chemotherapeutic drugs can affect the reproductive system and water homeostasis, whereas immunotherapeutic agents can cause hypophysitis and thyroiditis or other immune-mediated disorders. Treatment with radiopeptides may temporarily lead to radiation-induced hormone disturbances. As drugs targeting GEP-NENs are increasingly introduced, recognition and management of endocrine-related AEs may improve compliance and the quality of life of these patients.

Acute kidney injury in cancer patients

The increasing prevalence of neoplasias is associated with new clinical challenges, one of which is acute kidney injury (AKI). In addition to possibly constituting a clinical emergency, kidney failure significantly interferes with the choice and continuation of antineoplastic therapy, with prognostic implications in cancer patients. Some types of neoplasia are more susceptible to AKI, such as multiple myeloma and renal carcinoma. In cancer patients, AKI can be divided into pre-renal, renal (intrinsic), and post-renal. Conventional platinum-based chemotherapy and new targeted therapy agents against cancer are examples of drugs that cause an intrinsic renal lesion in this group of patients. This topic is of great importance to the daily practice of nephrologists and even constitutes a subspecialty in the field, the onco-nephrology.

The potential role of mitochondrial impairment in the pathogenesis of imatinib-induced renal injury

Imatinib is a tyrosine kinase inhibitor widely administered against chronic myeloid leukemia. On the other hand, drug-induced kidney proximal tubular injury, electrolytes disturbances, and renal failure is a clinical complication associated with imatinib therapy. There is no precise cellular mechanism(s) for imatinib-induced renal injury. The current investigation aimed to evaluate the role of mitochondrial dysfunction and oxidative stress in the pathogenesis of imatinib nephrotoxicity. Rats received imatinib (50 and 100 mg/kg, oral, 14 consecutive days). Serum and urine biomarkers of renal injury and markers of oxidative stress in the kidney tissue were assessed. Moreover, kidney mitochondria were isolated, and mitochondrial indices, including mitochondrial depolarization, dehydrogenases activity, mitochondrial permeabilization, lipid peroxidation (LPO), mitochondrial glutathione levels, and ATP content were determined. A significant increase in serum (Creatinine; Cr and blood urea nitrogen; BUN) and urine (Glucose, protein, gamma-glutamyl transferase; γ-GT, and alkaline phosphatase; ALP) biomarkers of renal injury, as well as serum electrolytes disturbances (hypokalemia and hypophosphatemia), were evident in imatinib-treated animals. On the other hand, imatinib (100 mg/kg) caused an increase in kidney ROS and LPO. Renal tubular interstitial nephritis, tissue necrosis, and atrophy were evident as tissue histopathological changes in imatinib-treated rats. Mitochondrial parameters were also adversely affected by imatinib administration. These data represent mitochondrial impairment, renal tissue energy crisis, and oxidative stress as possible mechanisms involved in the pathogenesis of imatinib-induced renal injury and serum electrolytes disturbances.

Urea in cancer patients with chronic SIAD-induced hyponatremia: Old drug, new evidence

BACKGROUND

Syndrome of inappropriate antidiuresis (SIAD) is the main cause of hyponatremia in cancer patients. International guidelines indicate urea as an interesting option for chronic SIAD. Nevertheless, strong data to support its use are lacking, and its role in oncologic patients has not been described so far.

MATERIAL AND METHODS

We retrospectively analysed 36 cancer patients affected by moderate or profound SIAD-induced chronic hyponatremia, who started oral urea (initial daily dose 15 g or 30 g) without fluid restriction between July 2013 and July 2018. We analysed mean serum sodium (sNa) increase after 24 hours and percentages of patients who reached eunatremia within 14, 30 and 60 days of treatment, stratifying according to the degree of hyponatremia at diagnosis. Clinical evaluation and biochemical assessment were periodically performed.

RESULTS

Mean sNa was 123 [±4] mmol/L at baseline; after 24 hours of treatment, a mean increase of 5 [±3] mmol/L was observed. Eunatremia was reached by 55.6%, 86.1% and 91.7% patients within 14, 30 and 60 days of treatment, respectively. Trends in sNa normalization were similar in patients with moderate and profound hyponatremia at diagnosis. Rapid sNa overcorrection was avoided in all cases. Urea  was interrupted within  the first  2 months  of treatment in 10 patients, in half cases for rapid neoplastic progression and in the remaining patients for the drug taste.

CONCLUSIONS

In our study, urea was effective in correcting chronic hyponatremia among cancer patients with SIAD. Almost all patients reached eunatremia within the first month of therapy, and urea was globally well tolerated.

The footprints of mitochondrial impairment and cellular energy crisis in the pathogenesis of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and Fanconi's syndrome: A comprehensive review

Fanconi's Syndrome (FS) is a disorder characterized by impaired renal proximal tubule function. FS is associated with a vast defect in the renal reabsorption of several chemicals. Inherited and/or acquired conditions seem to be connected with FS. Several xenobiotics including many pharmaceuticals are capable of inducing FS and nephrotoxicity. Although the pathological state of FS is well described, the exact underlying etiology and cellular mechanism(s) of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and FS are not elucidated. Constant and high dependence of the renal reabsorption process to energy (ATP) makes mitochondrial dysfunction as a pivotal mechanism which could be involved in the pathogenesis of FS. The current review focuses on the footprints of mitochondrial impairment in the etiology of xenobiotics-induced FS. Moreover, the importance of mitochondria protecting agents and their preventive/therapeutic capability against FS is highlighted. The information collected in this review may provide significant clues to new therapeutic interventions aimed at minimizing xenobiotics-induced renal injury, serum electrolytes imbalance, and FS.

Arginine Vasopressin and Posterior Reversible Encephalopathy Syndrome Pathophysiology: the Missing Link?

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological entity characterized by a typical brain edema. Its pathogenesis is still debated through hypoperfusion and hyperperfusion theories, which have many limitations. As PRES occurs almost exclusively in clinical situations with arginine vasopressin (AVP) hypersecretion, such as eclampsia and sepsis, we hypothesize that AVP plays a central pathophysiologic role. In this review, we discuss the genesis of PRES and its symptoms through this novel approach. We theorize that AVP axis stimulation precipitates PRES development through an increase in AVP secretion or AVP receptor density. Activation of vasopressin V_1a receptors leads to cerebral vasoconstriction, causing endothelial dysfunction and cerebral ischemia. This promotes cytotoxic edema through hydromineral transglial flux dysfunction and may increase endothelial permeability, leading to subsequent vasogenic brain edema. If our hypothesis is confirmed, it opens new perspectives for better patient monitoring and therapies targeting the AVP axis in PRES.

Importance of magnesium sulfate supplementation in the prevention of hypomagnesemia and hypocalcemia during chemoradiation in head and neck cancer

In advanced squamous cell carcinoma of the head and neck, concomitant radiotherapy with cisplatin and/or cetuximab is frequently combined with cisplatin-based induction chemotherapy, which can cause severe hypomagnesemia, hypocalcemia, and hypokalemia. The aim of our study was to analyze the effects of magnesium sulfate supplementation on the incidence of hypomagnesemia, hypokalemia, and hypocalcemia during four cycles of TPF (docetaxel, cisplatin, and 5-fluorouracil) induction chemotherapy followed by concomitant radiotherapy (CRT) with cisplatin and cetuximab. Twenty-five patients included in a phase II prospective study received routine magnesium sulfate infusions before each cycle of cisplatin, and additional supplementation based on laboratory findings. During TPF, the incidence of grade 1/2 and grade 3/4 hypomagnesemia was 16% and 4%, respectively; and increased despite magnesium supplementation during CRT to 72% and 8%, respectively. During TPF, a grade 2 and grade 4 hypocalcemia occurred in 8% and 4%, respectively; and during CRT, it reached 36% (grade 1/2). Grade 1 hypokalemia only was observed during TPF (4%) and CRT (8%). The median amounts of supplemented magnesium sulfate during TPF and CRT were 20 mEq and 50 mEq, respectively. It appears that a low incidence of grade 3/4 hypomagnesemia and hypocalcemia in our patients resulted from intensive magnesium supplementation. Thorough measurements of magnesium and calcium during cisplatin-based chemoradiation protocols in patients with head and neck cancer are crucial in preventing the development of grade 3/4 hypomagnesemia and hypocalcemia.

Natural killer/T-cell lymphoma with concomitant syndrome of inappropriate antidiuretic hormone secretion: A case report and review of literature

We report a case of natural killer (NK)/T-cell lymphoma with concomitant syndrome of inappropriate antidiuretic hormone secretion (SIADH). The patient was a 64-year-old woman with a history of nasopharyngeal carcinoma of over 30 years. She was admitted with a chief complaint of intermittent fever for 2 mo. Palpation after admission indicated a swollen lymph node below the left jaw. Multiple imaging examinations on admission indicated multiple enlarged lymph nodes throughout the body. We performed a left submandibular lymph node biopsy, and the results revealed NK/T-cell lymphoma. A biochemical examination indicated Epstein-Barr virus positivity. At the same time, the patient developed hyponatremia. Based on her laboratory examination and clinical manifestation, decreased plasma osmolality, urine osmolality greater than plasma osmolality, lack of skin swelling, normal blood pressure, normal renal function, no adrenal function detected on serology, and no abnormalities in imaging examination of the adrenal glands, the likelihood of SIADH in the patient was high. After fluid restriction and administration of sodium chloride, the patient’s blood sodium level gradually increased. Subsequently, the immune function of the patient declined, there were severe symptoms of infection, and she died of respiratory failure. NK/T-cell lymphoma associated with SIADH has not, to our knowledge, been previously reported in PubMed. This case emphasizes the importance of monitoring serum ion levels, especially serum sodium, in patients with NK/T-cell lymphoma.

Prognostic Impact of Hypochloremia in Patients With Stage I to III Colorectal Cancer After Radical Resection

BACKGROUND

Recent studies have suggested that electrolyte disorders might be a negative prognostic factor for some diseases.

OBJECTIVE

The purpose of this study was to systematically evaluate the prognostic role of electrolyte disorders in patients with stage I to III colorectal cancer who received radical surgical resection.

DESIGN

This study was retrospectively performed.

SETTINGS

The study was conducted at a single tertiary care center.

PATIENTS

Patients with colorectal cancer who underwent radical resection in between April 2007 and April 2014 were included.

MAIN OUTCOME MEASURES

The Kaplan-Meier method was adopted to estimate the overall and disease-free survival with and without propensity score matching.

RESULTS

In total, our study recruited 5089 eligible patients. In prematching analysis, patients with hypochloremia showed both shorter overall survival (HR = 0.943 (95% CI, 0.908-0.980); p = 0.003) and disease-free survival (HR = 0.957 (95% CI, 0.933-0.981); p < 0.001) than those with normal serum chloride levels. In postmatching analysis, 770 patients from each group were compared, and the results further confirmed that hypochloremia was significantly associated with worse overall survival (HR = 0.646 (95% CI, 0.489-0.855); p = 0.002) and disease-free survival (HR = 0.782 (95% CI, 0.647-0.944); p = 0.01), with the hypochloremia group as a reference.

LIMITATIONS

The study was limited by its retrospective nature.

CONCLUSIONS

Hypochloremia diagnosed before treatment can independently prognosticate the overall and disease-free survival for patients with stage I to Ш colorectal cancer after radical resection. Intensive surveillance and management might improve the survival outcome for patients with hypochloremia. See Video Abstract at http://links.lww.com/DCR/A727.

Acute kidney injury and electrolyte disorders in the critically ill patient with cancer

PURPOSE OF REVIEW

Patients with cancer increasingly make up a significant proportion of patients receiving care in the intensive care unit (ICU). Acute kidney injury and cancer-associated electrolyte disorders are encountered in many of these patients and can significantly impact both short-term and long-term outcomes.

RECENT FINDINGS

Advances in chemotherapeutic regimens as well as in our understanding of cancer-associated kidney disease highlight the need for specialized knowledge of the unique causes and therapies required in this subset of critically ill patients. This is especially the case as targeted cancer therapies may have off-target effects that need to be recognized in a timely manner.

SUMMARY

This review outlines key knowledge areas for critical care physicians and nephrologists caring for patients with cancer and associated kidney issues such as acute kidney injury and electrolyte disorders. Specifically, understanding kidney-specific effects of new chemotherapeutic approaches is outlined, and provides an up-to-date compendium of these effects.

Impact of Different Serum Potassium Levels on Postresuscitation Heart Function and Hemodynamics in Patients with Nontraumatic Out-of-Hospital Cardiac Arrest

Background

Sustained return of spontaneous circulation (ROSC) can be initially established in patients with out-of-hospital cardiac arrest (OHCA); however, the early postresuscitation hemodynamics can still be impaired by high levels of serum potassium (hyperkalemia). The impact of different potassium levels on early postresuscitation heart function has remained unclear. We aim to analyze the relationship between different levels of serum potassium and postresuscitation heart function during the early postresuscitation period (the first hour after achieving sustained ROSC).

Methods

Information on 479 nontraumatic OHCA patients with sustained ROSC was retrospectively obtained. Measures of early postresuscitation heart function (rate, blood pressure, and rhythm), hemodynamics (urine output and blood pH), and the duration of survival were analyzed in the case of different serum potassium levels (low: <3.5; normal: 3.5–5; high: >5 mmol/L).

Results

Most patients (59.9%, n = 287) had previously presented with high levels of potassium. Bradycardia, nonsinus rhythm, urine output <1 ml/kg/hr, and acidosis (pH < 7.35) were more common in patients with high levels of potassium (all p < 0.05). Compared with hyperkalemia, a normal potassium level was more likely to be associated with a normal heart rate (OR: 2.97, 95% CI: 1.74–5.08) and sinus rhythm (OR: 2.28, 95% CI: 1.45–3.58). A low level of potassium was more likely to be associated with tachycardia (OR: 3.54, 95% CI: 1.32–9.51), urine output >1 ml/kg/hr (OR: 5.35, 95% CI: 2.58–11.10), and nonacidosis (blood pH >7.35, OR: 7.74, 95% CI: 3.78–15.58). The duration of survival was shorter in patients with hyperkalemia than that in patients whose potassium levels were low or normal (p < 0.05).

Conclusion

Early postresuscitation heart function and hemodynamics were associated with the serum potassium level. A high potassium level was more likely to be associated with bradycardia, nonsinus rhythm, urine output <1 ml/kg/hr, and acidosis. More importantly, a high potassium level decreased the duration of survival.

[Drug nephrotoxicity]

Drug-induced nephrotoxicity (DIN) remains a current problem with economic and medical consequences. It affects all nephron segments. Recovery of renal function is based on the identification of risk factors, early diagnosis of renal disease, rapid (if possible) cessation of the causative agent and, in some cases, adjunctive therapy. Prevention is based on identification of early markers of DIN, correction of risk factors, initial assessment of renal function for adequate dosage adjustment and exclusion of other nephrotoxic factors. It has recently been proposed to standardize the phenotype of iatrogenic renal disease and, on the other hand, new markers of renal toxicity allowing early diagnosis and therefore better management of nephrotoxicity.

The confused oncologic patient: a rational clinical approach

PURPOSE OF REVIEW

The purpose of this review is to provide a practical clinical approach to confusion in the patient with cancer. Confusion in the cancer population has a broader differential diagnosis than in the general medical population. The clinician must consider the usual differential diagnoses as well as causes unique to the cancer patient including direct complications from the cancer and indirect complications related to cancer treatment.

RECENT FINDINGS

In the recent age of precision medicine, the oncologist now utilizes the genomic profile of both the patient and the tumor to provide advanced biologic therapies including targeted anticancer drugs, antiangiogenic agents, and immunotherapy. Such advances carry with them an emerging pattern of neurotoxicity which, although less well described in the literature, is now an important consideration to the clinical approach to confusion in cancer patients.

SUMMARY

Confusion is the most common neurologic complication in cancer and is associated with significant morbidity, mortality, and prolonged hospital stays resulting in increased healthcare costs. Early recognition and treatment of delirium is essential to improve clinical outcomes.

Hyponatremia in the elderly: challenges and solutions

Decreased serum sodium concentration is a rather frequent electrolyte disorder in the elderly population because of the presence of factors contributing to increased antidiuretic hormone, the frequent prescription of drugs associated with hyponatremia and also because of other mechanisms such as the “tea and toast” syndrome. The aim of this review is to present certain challenges in the evaluation and treatment of hyponatremia in the elderly population and provide practical solutions. Hyponatremia in elderly subjects is mainly caused by drugs (more frequently thiazides and antidepressants), the syndrome of inappropriate antidiuretic hormone secretion (SIAD) or endocrinopathies; however, hyponatremia is multifactorial in a significant proportion of patients. Special attention is needed in the elderly population to exclude endocrinopathies as a cause of hyponatremia before establishing the diagnosis of SIAD, which then requires a stepped diagnostic approach to reveal its underlying cause. The treatment of hyponatremia depends on the type of hyponatremia. Special attention is also needed to correct serum sodium levels at the appropriate rate, especially in chronic hyponatremia, in order to avoid the osmotic demyelination syndrome. In conclusion, both the evaluation and the treatment of hyponatremia pose many challenges in the elderly population.

Managing hyponatremia in lung cancer: latest evidence and clinical implications

Hyponatremia is the most common electrolyte disorder in lung cancer patients. This condition may be related to many causes including incidental medications, concurrent diseases and side effects of antineoplastic treatments or the disease itself. Although not frequently life-threatening, it is usually associated with prolonged hospitalization, delays in scheduled chemotherapy, worsening of patient performance status and quality of life and may also negatively affect treatment response and survival. Most of the available data focus on thoracic tumors, especially small-cell lung cancer (SCLC), where hyponatremia is frequently related to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Few studies specifically focus on non-small cell lung cancer (NSCLC) patients. Hyponatremia treatment needs to be personalized based on severity and duration of sodium serum reduction, extracellular fluid volume and etiology. However, literature data highlight the importance of early correction of the serum concentration levels. To achieve this the main options are fluid restriction, hypertonic saline, loop diuretics, isotonic saline, tolvaptan and urea. The aim of this review is to analyze the role of hyponatremia in lung cancer patients, evaluating causes, diagnosis, management and clinical implications.

MANAGEMENT OF ENDOCRINE DISEASE: Hypothyroidism-associated hyponatremia: mechanisms, implications and treatment

BACKGROUND

Patients with moderate to severe hypothyroidism and mainly patients with myxedema may exhibit reduced sodium levels (<135 mmol/L).

SUMMARY

The aim of this short review is the presentation of the mechanisms of hyponatremia and of the available data regarding its implications and treatment in patients with hypothyroidism. Hypothyroidism is one of the causes of hyponatremia, thus thyroid-stimulating hormone determination is mandatory during the evaluation of patients with reduced serum sodium levels. The main mechanism for the development of hyponatremia in patients with chronic hypothyroidism is the decreased capacity of free water excretion due to elevated antidiuretic hormone levels, which are mainly attributed to the hypothyroidism-induced decrease in cardiac output. However, recent data suggest that the hypothyroidism-induced hyponatremia is rather rare and probably occurs only in severe hypothyroidism and myxedema. Other possible causes and superimposed factors of hyponatremia (e.g. drugs, infections, adrenal insufficiency) should be considered in patients with mild/moderate hypothyroidism. Treatment of hypothyroidism and fluid restriction are usually adequate for the management of mild hyponatremia in patients with hypothyroidism. Patients with possible hyponatremic encephalopathy should be urgently treated according to current guidelines.

CONCLUSIONS

Severe hypothyroidism may be the cause of hyponatremia. All hypothyroid patients with low serum sodium levels should be evaluated for other causes and superimposed factors of hyponatremia and treated accordingly.