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.

Syndrome of inappropriate antidiuretic hormone secretion as an adverse reaction of ciprofloxacin: a case report and literature review.

Antidiuretic hormone (ADH) is secreted by the posterior pituitary gland. Unsuppressed release of ADH leads to hyponatremia. This condition is referred to as syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hereby, a case report is presented on ciprofloxacin-induced SIADH. A 67-year-old male patient was examined in the emergency room with symptoms of lethargy, headache, lack of attention, and a generally depressed mood lasting for three days. One week prior, empirical antimicrobial therapy involving ciprofloxacin for prostatitis was initiated. Laboratory analysis showed no relevant abnormalities except for hyponatremia (Na = 129 mmol/L). Chronic hyponatremia, thyroid dysfunction, and adrenal dysfunction were ruled out. Serum osmolality was 263 mOsmol/kg, urine osmolality was 206 mOsmol/kg, and urine sodium was 39 mmol/L. Given that all criteria for SIADH were met, ciprofloxacin was discontinued, and fluid restriction was advised. Four days later, the patient's serum sodium concentrations nearly normalized (Na = 135 mmol/L), and all symptoms resolved. The Naranjo Scale yielded a score of 8, supporting the likelihood of a probable adverse reaction to ciprofloxacin. This case is presented to raise awareness among clinicians about the potential of ciprofloxacin to cause even mild hyponatremia.

Urea como opción terapéutica en síndrome de antidiuresis inadecuada

El síndrome de antiduresis inadecuada (SADI) se produce por una alteración en el eje hipotálamo-neurohipófisis, por una falla en la respuesta regulatoria osmótica o por factores no osmóticos, con complicaciones en relación directa al grado de hiponatremia e impacto en la calidad de vida y mortalidad del paciente. El tratamiento consiste en la normalización de la natremia, y la búsqueda de la etiología. Presentamos el caso de un paciente adulto con el diagnóstico de SADI idiopático y trastorno neurocognitivo asociado, con respuesta favorable al tratamiento con urea.

Syndrome of Inappropriate Antidiuresis (SIAD), is produced by an alteration in the hypothalamus-neurohypophysis axis due to a failure in the osmotic regulatory response or non-osmotic factors, with complications directly related to the degree of hyponatremia and impact on quality of life and patient mortality. Management consists of normalization of natremia, and the search for the underlying etiology. We present the case of an adult patient diagnosed with idiopathic SIAD and associated neurocognitive disorder, with a favorable response to treatment with urea.

Hiponatremia severa por meningitis tuberculosa: complicación frecuente pero olvidada

Se presenta el caso de un paciente varón de 55 años que ingresó por alteración del estado de conciencia por una hiponatremia severa secundaria a una meningitis tuberculosa. No hubo mejoría de la hiponatremia al tratamiento con solución salina hipertónica, por lo cual se planteó el diagnóstico de síndrome de secreción inapropiada de hormona antidiurética (SIADH) y se evidenció mejoría con la restricción hídrica. El interés del presente caso es reportar una complicación frecuente pero olvidada de la meningitis tuberculosa.

We present the case of a 55-year-old male patient who was admitted due to an altered state of consciousness due to severe hyponatremia secondary to tuberculous meningitis. There was no improvement in hyponatremia after treatment with hypertonic saline solution, therefore the diagnosis of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) was proposed, and improvement was evidenced with fluid restriction. The interest of this case is to report a common but forgotten complication of tuberculous meningitis.

[Hyponatremia : Etiology, diagnosis and acute therapy]. / Hyponatriämie : Ätiologie, Diagnostik und Akuttherapie.

Hyponatremia is one of the most common electrolyte disorders in emergency departments and hospitalized patients. Serum sodium concentration is controlled by osmoregulation and volume regulation. Both pathways are regulated via the release of antidiuretic hormone (ADH). Syndrome of inappropriate release of ADH (SIADH) may be caused by neoplasms or pneumonia but may also be triggered by drug use or drug abuse. Excessive fluid intake may also result in a decrease in serum sodium concentration. Rapid alteration in serum sodium concentration leads to cell swelling or cell shrinkage, which primarily causes neurological symptoms. The dynamics of development of hyponatremia and its duration are crucial. In addition to blood testing, a clinical examination and urine analysis are essential in the differential diagnosis of hyponatremia.

Use of the osmolal gap in diagnosing mixed physiology hyponatremia in a child with B-cell acute lymphoblastic leukemia.

Hyponatremia is common among children undergoing treatment for hematologic malignancies and may be attributed to multiple underlying causes. In cases of hyponatremia due to mixed physiology, the osmolal gap, can identify pseudohyponatremia that may be masked by other causes.

Syndrome of Inappropriate Antidiuresis and Diabetes Insipidus as Two Sides of the Same Coin in Hypothalamic Lymphoma: A Case Report.

BACKGROUND: Hypothalamic-pituitary region lymphoma is rare and diabetes insipidus (DI) represents one of the most common endocrine manifestations. We report the first case of hypothalamic lymphoma associated with both the syndrome of inappropriate antidiuresis (SIAD) and DI. CASE PRESENTATION: A 64-year-old woman with a history of stage IV large B-cell non-Hodgkin lymphoma, underwent atypical right lung resection for pulmonary nodules. A few days after surgery, the patient presented severe normovolemic hyponatremia and serum hypo-osmolarity, therefore, we suspected a paraneoplastic syndrome (SIAD) related to the lung neoplasm, histologically diagnosed as typical carcinoid. The brain magnetic resonance imaging (MRI) showed a 9 mm lesion in the hypothalamic region that significantly increased one month later with the onset of neurological symptoms. A trans-sphenoidal biopsy showed localization of the large B-cell lymphoma. After surgery, the patient presented with polyuria and polydipsia, so desmopressin therapy was started. In the following days, serum osmolarity and sodium fluctuated between normal and low values, then DI was excluded, and SIAD became more likely. Desmopressin therapy was discontinued and hyponatremia was treated with sodium infusion. Hypothalamic lymphoma was treated with chemotherapy and radiotherapy with substantial shrinkage. The hyponatremia persisted during anticancer treatments and improved only after radiotherapy, confirming paraneoplastic SIAD. CONCLUSION: Lymphomas of the hypothalamic region can cause electrolyte imbalance for various causes. The differential diagnosis between SIAD, DI and impaired thirst centers may not be straightforward and the electrolyte disorders must be evaluated step by step in all different stages of the disease.

Encefalitis límbica asociada a secreción inadecuada de hormona antidiurética. Reporte de un caso y revisión de la literatura / Limbic encephalitis associated with inappropriate secretion of antidiuretic hormone. A case report and literature review / Encefalite límbica associada à secreção inapropriada de hormônio antidiurético. Relato de caso e revisão da literatura

La encefalitis límbica (EL) autoinmune es una afección neurológica infrecuente de curso subagudo con manifestaciones neuropsicológicas. Actualmente el tratamiento inmunoterápico agudo o de mantenimiento es dirigido según el anticuerpo neural acompañante y la presencia o ausencia de cáncer. Presentamos el caso de una mujer de 52 años con hipotiroidismo autoinmune, síndrome de secreción inadecuada de hormona antidiurética (SIADH) e hiponatremia (hipoNa) persistente, con evolución progresiva de perdida de la memoria y crisis distónicas faciobraquiales (DFBC) a quien se le realiza un diagnóstico oportuno de encefalitis límbica. Recibió tratamiento intravenoso combinado en base a corticoides e inmunoglobulina con buena respuesta y morbilidad mínima neuropsicológica. El reconocimiento de esta patología permite un diagnóstico y tratamiento temprano, imprescindible para mejorar el pronóstico de estos pacientes.

Autoimmune limbic encephalitis is a rather unusual neurological condition with subacute progression and neuropsychological symptoms. Currently, acute or maintenance treatment with immunotherapy is targeted depending on the accompanying neural specific antibody and the presence or absence of cancer. The study presents the case of a 52-year-old woman suffering from autoimmune hypothyroidism, syndrome of inappropriate secretion of anti-diuretic hormone (SIADH) and persistent hyponatremia, with progressive evolution which involved memory loss and faciobrachial dystonic seizures (FBDS). She was timely diagnosed with limbic encephalitis and was treated with intravenous combined corticosteroids and immunoglobulin therapy. Response was good, with minimum neuropsychological. Recognizing this condition allows for early diagnosis and treatment, what is key to improve the prognosis of these patients.

A encefalite límbica (LE) autoimune é uma condição neurológica rara de curso subagudo com manifestações neuropsiquiátrica. Atualmente, o tratamento com imunoterapia aguda ou de manutenção é orientado de acordo com o anticorpo neural e a presença ou ausência de câncer. Apresentamos o caso de uma mulher de 52 anos com hipotireoidismo autoimune, síndrome de secreção inapropriada de hormônio antidiurético e hiponatremia persistente, com evolução progressiva da perda de memória e crises distônicas faciobraquiais que foi diagnosticada oportunamente como encefalite límbica. Recebeu tratamento endovenoso combinado à base de corticoide e imunoglobulina com boa resposta e morbidade neuropsiquiátrica mínima. O reconhecimento desta patologia permite um diagnóstico e tratamento precoces, essenciais para melhorar o prognóstico desses pacientes.

The "new normal" osmotic threshold: Osmostat reset.

Hyponatremia is the most common electrolyte disorder in hospitalized patients. The syndrome of inappropriate antidiuresis (SIAD) is one of the leading causes of hyponatremia. Although not widely known, SIAD has a vast spectrum of etiologies and differential diagnoses and has been classically divided into four types (A, B, C, D). Frequently, when we use the term SIAD in clinical practice, it refers to subtype A, the so-called classic SIAD. The purpose of reporting this case is to make the clinicians aware of a specific subtype of SIAD, type C, an underdiagnosed entity called osmostat reset (OR). Due to similarities, OR often ends up being misinterpreted as classic SIAD. However, the differentiation between these two entities is crucial due to treatment implications. This manuscript highlights the use of an algorithm, based on the fraction of uric acid excretion, as an approach to the differential diagnosis of hyponatremia.

Routine postoperative fluid restriction to prevent syndrome of inappropriate antidiuretic hormone secretion after transsphenoidal resection of pituitary adenoma.

OBJECTIVE: Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a common problem during the postoperative course after pituitary surgery. Although treatment of this condition is well characterized, prevention strategies are less studied and reported. The authors sought to characterize outcomes and predictive factors of SIADH after implementation of routine postoperative fluid restriction for patients undergoing endoscopic transsphenoidal surgery for pituitary adenoma. METHODS: In March 2018, routine postoperative fluid restriction to 1000 ml/day for 7 days was instituted for all patients who underwent surgery for pituitary adenoma. These patients were compared with patients who underwent surgery for pituitary adenoma between March 2016 and March 2018, prior to implementation of routine fluid restriction. Patients with preoperative history of diabetes insipidus (DI) or concern for postsurgical DI were excluded. Patients were followed by neuroendocrinologists and neurosurgeons, and sodium levels were checked between 7 and 10 days postoperatively. SIADH was defined by a serum sodium level less than 136 mmol/L, with or without symptoms within 10 days after surgery. Thirty-day readmission was recorded and reviewed to determine underlying reasons. RESULTS: In total, 82 patients in the fluid-unrestricted cohort and 135 patients in the fluid-restricted cohort were analyzed. The patients in the fluid-restricted cohort had a significantly lower rate of postoperative SIADH than patients in the fluid-unrestricted cohort (5% vs 15%, adjusted OR [95% CI] 0.1 [0.0-0.6], p = 0.01). Higher BMI was associated with lower rate of postoperative SIADH (adjusted OR [95%] 0.9 [0.9-1.0], p = 0.03), whereas female sex was associated with higher rate of SIADH (adjusted OR [95% CI] 3.1 [1.1-9.8], p = 0.03). There was no difference in the 30-day readmission rates between patients in the fluid-unrestricted and fluid-restricted cohorts (4% vs 7%, adjusted OR [95% CI] 0.5 [0-5.1], p = 0.56). Thirty-day readmission was more likely for patients with history of hypertension (adjusted OR [95% CI] 5.7 [1.3-26.3], p = 0.02) and less likely for White patients (adjusted OR [95% CI] 0.3 [0.1-0.9], p = 0.04). CONCLUSIONS: Routine fluid restriction reduced the rate of SIADH in patients who underwent surgery for pituitary adenoma but was not associated with reduction in 30-day readmission rate.

Neuronal Swelling: A Non-osmotic Consequence of Spreading Depolarization.

An acute reduction in plasma osmolality causes rapid uptake of water by astrocytes but not by neurons, whereas both cell types swell as a consequence of lost blood flow (ischemia). Either hypoosmolality or ischemia can displace the brain downwards, potentially causing death. However, these disorders are fundamentally different at the cellular level. Astrocytes osmotically swell or shrink because they express functional water channels (aquaporins), whereas neurons lack functional aquaporins and thus maintain their volume. Yet both neurons and astrocytes immediately swell when blood flow to the brain is compromised (cytotoxic edema) as following stroke onset, sudden cardiac arrest, or traumatic brain injury. In each situation, neuronal swelling is the direct result of spreading depolarization (SD) generated when the ATP-dependent sodium/potassium ATPase (the Na+/K+ pump) is compromised. The simple, and incorrect, textbook explanation for neuronal swelling is that increased Na+ influx passively draws Cl- into the cell, with water following by osmosis via some unknown conduit. We first review the strong evidence that mammalian neurons resist volume change during acute osmotic stress. We then contrast this with their dramatic swelling during ischemia. Counter-intuitively, recent research argues that ischemic swelling of neurons is non-osmotic, involving ion/water cotransporters as well as at least one known amino acid water pump. While incompletely understood, these mechanisms argue against the dogma that neuronal swelling involves water uptake driven by an osmotic gradient with aquaporins as the conduit. Promoting clinical recovery from neuronal cytotoxic edema evoked by spreading depolarizations requires a far better understanding of molecular water pumps and ion/water cotransporters that act to rebalance water shifts during brain ischemia.

Can treatment response to SGLT2-inhibitors in syndrome of inappropriate antidiuresis be predicted by copeptin, natriuretic peptides and inflammatory markers?

PURPOSE: The syndrome of inappropriate antidiuresis (SIAD) is the main cause of hyponatremia and the SGLT2-inhibitor empagliflozin is a promising new treatment option. A biomarker predicting treatment response could optimize treatment success. MATERIALS AND METHODS: Secondary analysis of a trial including 84 hospitalized patients with SIAD-induced hyponatremia. Patients were randomized to four days of treatment with empagliflozin 25 mg/d (n = 43) or placebo (n = 41) with both groups receiving fluid restriction <1000 ml/d. Baseline levels of copeptin, the natriuretic peptides MR-proANP and NT-proBNP and C-reactive protein (CRP) were evaluated as predictors for treatment response defined as absolute sodium change, using linear regression models. Additionally, urinary sodium was assessed as predictor for non-response to fluid restriction alone by constructing the receiver-operating characteristic (ROC) curve. RESULTS: No clinically relevant predictive value for treatment response to empagliflozin could be found for copeptin, MR-proANP, NT-proBNP or CRP. A urinary sodium cut-off of >76 mmol/l led to a specificity of 91.7% [95% confidence interval (CI): 75%, 100%] and sensitivity of 51.9% [33.3%, 70.4%] to predict non-response to fluid restriction alone. CONCLUSIONS: Based on our data, no biomarker could be identified as predictor for treatment response to empagliflozin. Urinary sodium was confirmed as a good marker for non-response to fluid restriction in SIAD patients. Clinical trial registration: ClinicalTrials.gov (Number: NCT02874807).

Syndrome of Inappropriate Antidiuretic Hormone Secretion in a Patient with Uncontrolled Tyrosinaemia Type 1.

Syndrome of inappropriate antidiuretic hormone (SIADH) secretion is a recognisable complication of acute porphyria. We report a nine-year-old female patient with hereditary tyrosinaemia type 1 and poor adherence to nitisinone therapy who presented with acute abdominal pain, vomiting and lethargy at Sultan Qaboos University Hospital, Muscat, Oman in 2016. She subsequently developed generalised tonic-clonic seizures attributable to severe hyponatremia that met the diagnostic criteria of SIADH. The acute porphyria screen also appeared positive. The patient responded well to fluid restriction and was discharged home without immediate neurological sequelae. Although acute porphyria is also a recognised complication of uncontrolled tyrosinaemia type 1, to the best of the authors' knowledge, no patient with tyrosinaemia type 1 has been reported to present with SIADH.

Development of Inappropriate Vasopressin Secretion in Association With Lumbar Cerebrospinal Fluid Drainage in an Adult With Traumatic Basilar Skull Fracture.

OBJECTIVE: Hyponatremia associated with cerebrospinal fluid (CSF) drainage is primarily limited to pediatric patients. Only 1 case in an adult, after pituitary surgery, has been described. We present the first adult case, to our knowledge, of lumbar CSF drainage associated with the syndrome of inappropriate antidiuretic hormone (SIADH) in a patient with a traumatic basilar skull fracture. METHODS: Serum and urine samples were evaluated for hyponatremia. Computed tomography and magnetic resonance imaging were performed to evaluate the fractures. RESULTS: A 31-year-old woman was hospitalized with traumatic facial and skull base fractures and managed conservatively. Four days into her hospital stay, she underwent lumbar CSF drainage for 6 days to treat a CSF leak. On examination, the patient remained hemodynamically stable and euvolemic. Sodium levels decreased from 142 to 136 mmol/L (normal, 135-146 mmol/L) on the day before and after lumbar drain placement, respectively, down to a nadir of 124 mmol/L over 3 subsequent days. Serum osmolality was 260 mOsm/kg (275-295 mOsm/kg); urine osmolality, 482 mOsm/kg; urine Na, 175 mmol/L; and thyroid-stimulating hormone, 4.0 µIU/mL (0.3-4.7 µIU/mL). The patient received treatment with sodium tablets, fluid restriction, and hypertonic saline for a diagnosis of SIADH. Sodium levels normalized from 131 to 136 mmol/L within 16 hours after lumbar drain removal. CONCLUSION: This case illustrated a temporal association of SIADH with CSF drainage in an adult. Although this could be coincidental because a basilar skull fracture can lead to SIADH, it raises the possibility that CSF lumbar drainage contributed to the patient's SIADH.

SIADH in the context of localised Herpes-Zoster infection.

Not required for Clinical Vignette.

Altered Mental Status and Hyponatremia After 20 Hours of Amiodarone Therapy.

A 66-year-old woman with no relevant medical history presented at the emergency department with new-onset atrial fibrillation. We initiated intravenous amiodarone therapy. At 20 hours, the patient experienced severe neurologic symptoms, hyponatremia, and syndrome of inappropriate antidiuretic hormone. We discontinued amiodarone, infused saline solution, and restricted the patient's fluid intake. She recovered in 3 days. This case illustrates that amiodarone-induced syndrome of inappropriate antidiuretic hormone with hyponatremia can occur far earlier than expected during acute amiodarone therapy.

Fluid Replacement Versus Fluid Restriction in COVID-19 Associated Hyponatremia.

Hyponatremia is one of the most frequently observed electrolyte abnormalities in coronavirus disease 2019 (COVID-19). Literature describes syndrome of inappropriate anti diuretic hormone (SIADH) as the mechanism of hyponatremia in COVID-19 requiring fluid restriction for management. However, it is important to rule out other etiologies of hyponatremia in such cases keeping in mind the effect of an alternate etiology on patient management and outcome. We present a case of hypovolemic hyponatremia in a patient with COVID-19, which unlike SIADH, required fluid replacement early in the disease course for its correction. A 52-year-old Filipino gentleman presented with a three-week history of diarrhea and symptomatic hyponatremia. There was no history of fever or respiratory symptoms. Physical examination revealed a dehydrated and confused middle-aged gentleman. Labs revealed lymphopenia, thrombocytopenia, and severe hyponatremia (108 mmol/L). Blood cultures and stool workup were negative. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nasopharyngeal swab was positive. Hyponatremia workup excluded SIADH. The patient had hypovolemic hyponatremia due to gastrointestinal (GI) losses and was managed with saline infusion for correction of hyponatremia with improvement in his clinical status. Hyponatremia in COVID-19 is not only secondary to SIADH but can also be due to other etiologies. Hypovolemic hyponatremia should be distinguished from SIADH as these conditions employ different management strategies, and early diagnosis and management of hypovolemic hyponatremia affects morbidity and mortality.

Recurrent Severe Hyponatremia in a Patient with Sjögren's Syndrome.

Sjögren's syndrome (SS) is an autoimmune disease that presents with exocrine gland dysfunction. Renal involvement is common in SS and often results in tubulointerstitial nephritis, renal tubular acidosis, and Fanconi's syndrome. Electrolyte imbalances are commonly the first symptom of renal involvement of SS. The most common feature of dysnatremia in SS is hypernatremia with diabetes insipidus. However, cases of hyponatremia with syndrome of inappropriate antidiuretic hormone secretion (SIADH) are rarely reported in patients with SS. Herein, we report a case of recurrent severe SIADH in a patient with SS.

[Hyponatremia in older persons (II)-A clear treatment : How to detect tricks and avoid pitfalls]. / Hyponatriämie im Alter (II) ­ eine klare Therapie : Tücken erkennen und Fallstricke umgehen.

The aim of this continuing medical education (CME) article (part II) is to describe the particular challenge of the treatment of hyponatremia, which occurs in older patients. This part II follows on from part I concerning the diagnosis in the previous volume. A staged approach is necessary. The best treatment is always when the underlying cause can be eliminated. Hyponatremia in older patients is mainly induced by the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. The authors use a concept for the first, second and third line strategy: (1) changing or discontinuation of drugs, (2) fluid restriction and (3) tolvaptan medication. The algorithm for treatment should be simple. It also contains recommendations for the correction rate. Caution is also needed in order to avoid the occurrence of an osmotic demyelination syndrome (ODS).