RESUMO
Boswellia serrata is an herbal extract from the Boswellia serrata tree that has anti-inflammatory and analgesic properties and alleviates pain caused by rheumatoid arthritis, gout, osteoarthritis, and sciatica. Syndrome of inappropriate antidiuretic hormone secretion accompanied by hyponatremia, seizures, and rhabdomyolysis as a manifestation of Boswellia serrata intoxication has not been reported previously. A 38-year-old female suffered clinically isolated syndrome and has since been regularly taking B. serrata capsules (200mg/d) to strengthen her immune system. She experienced hypersensitivity to light, ocular pain, nausea, dizziness, and lower limb weakness four days after receiving her first BNT162b2 vaccine dose, and she increased the dosage of B. serrata to five capsules (1000mg/d) one week after vaccination. After taking B. serrata at a dosage of 1000mg/d for 3 weeks, she was admitted to the intensive care unit because of a first, unprovoked generalized tonic-clonic seizure. The patient's workup revealed syndrome of inappropriate antidiuretic hormone secretion, which resolved completely upon treatment and discontinuation of B. serrata. In summary, B. serrata potentially causes syndrome of inappropriate antidiuretic hormone secretion when it is taken at high doses. Patients should not self-medicate.
Assuntos
Boswellia , Hiponatremia , Síndrome de Secreção Inadequada de HAD , Rabdomiólise , Convulsões , Humanos , Feminino , Adulto , Síndrome de Secreção Inadequada de HAD/diagnóstico , Síndrome de Secreção Inadequada de HAD/induzido quimicamente , Hiponatremia/induzido quimicamente , Hiponatremia/etiologia , Rabdomiólise/induzido quimicamente , Rabdomiólise/diagnóstico , Convulsões/etiologia , Convulsões/induzido quimicamente , Extratos Vegetais/efeitos adversosRESUMO
A man in his 60s presented to the clinic due to night sweats and weight loss following pneumonia. He was found to have hyponatraemia due to a syndrome of inappropriate antidiuretic hormone (SIADH). CT of the thorax was concerning for pulmonary nodules. He was ultimately diagnosed with pulmonary coccidioidomycosis (CM) and started on fluconazole 400 mg daily with improvement in symptoms. Due to the report of headaches, head MRI was conducted which suggested central nervous system (CNS) involvement. Cerebrospinal fluid analysis was consistent with CNS CM and head magnetic resonance angiography confirmed the presence of CNS vasculitis. Fluconazole dose was increased to 800 mg daily which the patient continued to tolerate and showed improvement. This report depicts a case of SIADH associated with CNS CM with vasculitis and demonstrates the importance of high clinical suspicion for SIADH secondary to CNS CM in the setting of hyponatraemia and headache.
Assuntos
Coccidioidomicose , Hiponatremia , Síndrome de Secreção Inadequada de HAD , Vasculite , Masculino , Humanos , Síndrome de Secreção Inadequada de HAD/complicações , Síndrome de Secreção Inadequada de HAD/diagnóstico , Hiponatremia/complicações , Coccidioidomicose/complicações , Coccidioidomicose/diagnóstico , Coccidioidomicose/tratamento farmacológico , Fluconazol , Vasopressinas , Vasculite/complicações , Sistema Nervoso CentralRESUMO
PURPOSE: To investigate the clinical characteristics of the syndrome of inappropriate antidiuretic hormone (SIADH) associated with nasal and paranasal malignant tumors. METHODS: Patients with locally advanced or recurrence/metastatic malignant tumors of the nasal and paranasal sinuses were included. The SIADH was diagnosed according to the diagnostic criteria. The clinical characteristics of SIADH patients were retrospectively analyzed. RESULTS: Six patients (6/188, 3.2%) met the diagnostic criteria of SIADH, including four olfactory neuroblastoma (4/26, 15.4%), one neuroendocrine carcinoma (1/9, 11.1%), and one squamous cell carcinoma (1/63, 1.6%). Five patients (83.3%) had severe hyponatremia; however, the hyponatremia could be improved by fluid restriction or tolvaptan. Three patients' SIADH were recovered during the chemotherapy and the other three were recovered after the surgery. CONCLUSION: The incidence of SIADH associated with nasal and paranasal malignant tumors is relatively more common in olfactory neuroblastoma and neuroendocrine carcinoma. The hyponatremia caused by SIADH may be corrected by fluid restriction or tolvaptan, and the SIADH may be recovered through anti-tumor therapy.
Assuntos
Carcinoma Neuroendócrino , Estesioneuroblastoma Olfatório , Hiponatremia , Síndrome de Secreção Inadequada de HAD , Neoplasias Nasais , Humanos , Síndrome de Secreção Inadequada de HAD/complicações , Síndrome de Secreção Inadequada de HAD/diagnóstico , Hiponatremia/etiologia , Hiponatremia/complicações , Tolvaptan/uso terapêutico , Estesioneuroblastoma Olfatório/complicações , Estudos Retrospectivos , Carcinoma Neuroendócrino/complicações , Neoplasias Nasais/complicações , Cavidade NasalAssuntos
Antagonistas dos Receptores de Hormônios Antidiuréticos , Hiponatremia , Síndrome de Secreção Inadequada de HAD , Humanos , Antagonistas dos Receptores de Hormônios Antidiuréticos/uso terapêutico , Síndrome de Secreção Inadequada de HAD/complicações , Síndrome de Secreção Inadequada de HAD/diagnóstico , Síndrome de Secreção Inadequada de HAD/tratamento farmacológico , Receptores de Vasopressinas , Vasopressinas/uso terapêuticoRESUMO
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.
Assuntos
Hiponatremia , Síndrome de Secreção Inadequada de HAD , Masculino , Humanos , Idoso , Síndrome de Secreção Inadequada de HAD/induzido quimicamente , Síndrome de Secreção Inadequada de HAD/diagnóstico , Síndrome de Secreção Inadequada de HAD/terapia , Hiponatremia/induzido quimicamente , Hiponatremia/diagnóstico , Ciprofloxacina/efeitos adversos , SódioRESUMO
BACKGROUND Hashimoto's encephalopathy (HE) is an autoimmune encephalopathy that can involve various symptoms including psychosis. Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) may be a complication in some neurological diseases. However, the simultaneous occurrence of subacute psychosis and SIADH as the manifestation of HE, observed in the present case, has rarely been reported. CASE REPORT A 72-year-old man was hospitalized with a 4-month history of abnormal behaviors, including talkativeness, stopping consumption of coffee and cigarettes, hoarding garbage, and sleep disorders. On physical examination, increased and incoherent speech with flight of idea and delusion were observed. The Mini-Mental State Examination score was 28/30. Laboratory findings included hyponatremia due to SIADH and a positive result for anti-thyroid and anti-NH2 terminal of alpha-enolase antibodies. Cerebrospinal fluid examination revealed only elevation of IL-6. Brain magnetic resonance imaging was unremarkable; however, (I-123)-iodoamphetamine single-photon emission computed tomography showed extensive hyperperfusion involving the brainstem and bilateral frontal and medial temporal lobes. Electroencephalography showed generalized slow waves, but there were no epileptiform discharges. After 2 courses of high-dose intravenous methylprednisolone followed by oral prednisolone, his symptoms improved. Based on the findings of clinical features and steroid responsiveness, he was diagnosed with HE. Oral prednisolone and antipsychotic drugs were decreased without a relapse and he was discharged to his home. CONCLUSIONS Although psychosis complicating SIADH is rare, HE should be considered in the differential diagnosis because of its treatment efficacy.
Assuntos
Encefalopatias , Síndrome de Secreção Inadequada de HAD , Transtornos Psicóticos , Masculino , Humanos , Idoso , Síndrome de Secreção Inadequada de HAD/diagnóstico , Síndrome de Secreção Inadequada de HAD/tratamento farmacológico , Síndrome de Secreção Inadequada de HAD/etiologia , Encefalopatias/diagnóstico , Encefalopatias/tratamento farmacológico , Encefalopatias/etiologia , Metilprednisolona/uso terapêutico , VasopressinasRESUMO
Reset osmostat syndrome (ROS) is characterized by a change of normal plasma osmolality threshold (decrease or increase), which leads to chronic dysnatremia (hypo- or hypernatremia). We have described a clinical case of ROS and chronic hyponatremia in a patient with chordoid glioma of the III ventricle. It is known that the patient had previously been diagnosed with hyponatremia (131-134 mmol/l). She has not hypothyroidism and hypocorticism. There is normal filtration function of the kidneys was (CKD-EPI 91.7 ml/mi/1,73m2). Urine osmolality and sodium level were studied to exclude of concentration kidney function disorder. During first three days after removal of the tumor of the third ventricle (chordoid glioma, WHO Grade II), the sodium level decreased to 119 mmol/l. Repeated infusions of 200-300 ml hypertonic 3% sodium chloride solution, gluco- and mineralocorticoid therapy was ineffective, increasing plasma sodium levels by 2-3 mmol/l with the return to the initial level during 6-8 hours. Hypopituitary disorders did not develop after surgery. With further observation, the sodium level remained within 126-129 mmol/l for 6 months after surgery. The water load test make exclude the classic syndrome of inappropriate secretion of antidiuretic hormone, and confirmed the diagnosis of RSO. Because of absence of clinical symptoms associated with hyponatremia, no medical correction was required, patient was recommended to clinical follow-up.
Assuntos
Glioma , Hiponatremia , Síndrome de Secreção Inadequada de HAD , Nefropatias , Feminino , Humanos , Hiponatremia/diagnóstico , Hiponatremia/etiologia , Hiponatremia/tratamento farmacológico , Síndrome de Secreção Inadequada de HAD/diagnóstico , Síndrome de Secreção Inadequada de HAD/complicações , Espécies Reativas de Oxigênio/uso terapêutico , Nefropatias/complicações , Sódio , Glioma/complicaçõesRESUMO
RATIONALE: Neuromyelitis optica spectrum disorder (NMOSD) is a demyelinating disease that causes lesions in areas with abundant aquaporin-4 (AQP4) channels, including the hypothalamus. Hypothalamic lesions can disrupt antidiuretic hormone regulation, resulting in hyponatremia due to syndrome of inappropriate antidiuretic hormone (SIADH). Various factors can trigger NMOSD, including viral infections. We report the case of a young female patient who presented with hyponatremia due to SIADH and was found to have bilateral hypothalamic lesions along with positive serum herpes simplex virus immunoglobulin M. PATIENT CONCERNS: An 18-year old female patient presented with fever and nausea that had persisted for 5 days. Three days after hospitalization, the patient complained of blurred vision, hiccups, and excessive daytime sleepiness. DIAGNOSIS: The patient hyponatremia was attributed to SIADH. Magnetic resonance imaging revealed bilateral lesions in the hypothalamus, and serum laboratory tests were positive for herpes simplex virus immunoglobulin M. On the 15th day of admission, the anti-AQP4 antibody test result was positive, leading to the diagnosis of NMOSD. INTERVENTIONS: On the initial suspicion of herpes encephalitis, treatment with acyclovir was initiated. However, upon the confirmation of after anti-AQP4 antibody, the patient was additionally treated with a high-dose intravenous steroid for 5 days. OUTCOMES: The patient fever, nausea, visual disturbances, and other complaints improved within 1 week of initiating steroid treatment. LESSONS: In young patients presenting with hyponatremia and suspected SIADH accompanied by neurological abnormalities, it is crucial to differentiate central nervous system diseases, including NMOSD, which can involve lesions in AQP4-abundant areas, such as the hypothalamus.
Assuntos
Herpes Simples , Hiponatremia , Síndrome de Secreção Inadequada de HAD , Neuromielite Óptica , Humanos , Feminino , Adolescente , Neuromielite Óptica/complicações , Neuromielite Óptica/diagnóstico , Neuromielite Óptica/tratamento farmacológico , Síndrome de Secreção Inadequada de HAD/complicações , Síndrome de Secreção Inadequada de HAD/diagnóstico , Hiponatremia/complicações , Aquaporina 4 , Herpes Simples/complicações , Náusea , Imunoglobulina M , Esteroides , AutoanticorposRESUMO
While it was previously believed that neuromyelitis optic spectrum disorder (NMOSD) mostly affected the optic nerves and the spinal cord, it is increasingly recognized that NMOSD can involve any area of the CNS where aquaporin-4 is highly expressed. These other areas can include the hypothalamus and the circumventricular organs that surround the third and fourth ventricles, serving as osmoregulators. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is one of the most common causes of hyponatremia and has been associated with NMOSD due to these lesions. In this report, we present a case of a patient with known NMOSD, who presented with dizziness, fatigue, and generalized weakness and whose workup revealed hyponatremia in the setting of SIADH and hypothalamic demyelinating lesions. This case illustrates an atypical presentation of NMOSD and the importance of looking for syndromes, such as SIADH. This can guide diagnostic testing, such as getting thin MRI cuts through the hypothalamus and brainstem, as well as advanced management techniques such as immunotherapy.
Assuntos
Hiponatremia , Síndrome de Secreção Inadequada de HAD , Doenças Neuroinflamatórias , Neuromielite Óptica , Adulto , Feminino , Humanos , Tontura/complicações , Fadiga/complicações , Hiponatremia/complicações , Hiponatremia/diagnóstico , Hiponatremia/terapia , Hipotálamo/patologia , Síndrome de Secreção Inadequada de HAD/complicações , Síndrome de Secreção Inadequada de HAD/diagnóstico , Síndrome de Secreção Inadequada de HAD/terapia , Imageamento por Ressonância Magnética , Doenças Neuroinflamatórias/complicações , Doenças Neuroinflamatórias/patologia , Neuromielite Óptica/complicações , Neuromielite Óptica/patologia , ImunoterapiaRESUMO
BACKGROUND: Hyperimmunoglobulin E syndrome (HIES) due to dedicator of cytokinesis8 (DOCK8) deficiency may present in infancy and childhood with different clinical features involving recurrent infections, allergic dysregulation, and autoimmunity. CASE: In this report, we describe a patient who first presented with severe hypereosinophilia and went on to develop the syndrome of inappropriate antidiuretic hormone secretion (SIADH) in the context of a severe herpes infection. Investigation revealed the presence of underlying DOCK8 deficiency presenting with atypical clinical features. CONCLUSIONS: Distinct inflammatory features associated with infections may be seen in the course of primary immunodeficiency diseases, and early functional and molecular genetic tests will aid the proper management.
Assuntos
Eosinofilia , Hipersensibilidade , Síndrome de Secreção Inadequada de HAD , Síndrome de Job , Criança , Humanos , Fatores de Troca do Nucleotídeo Guanina/genética , Hipersensibilidade/complicações , Síndrome de Secreção Inadequada de HAD/diagnóstico , Síndrome de Secreção Inadequada de HAD/genética , Síndrome de Secreção Inadequada de HAD/complicações , Síndrome de Job/complicações , Síndrome de Job/diagnóstico , Síndrome de Job/genética , Vasopressinas , LactenteRESUMO
OBJECTIVES: Hypothalamic hamartoma (HH) typically presents with gonadotrophin-dependent precocious puberty and/or seizures. Other endocrine disturbances are rare. We describe an infant with syndrome of inappropriate secretion of anti-diuretic hormone (SIADH) and a HH. CASE PRESENTATION: A 6-week-old infant presented with seizures and life-threatening hyponatremia. A HH was identified on magnetic resonance imaging. Clinical examination and biochemistry were consistent with SIADH, and serum copeptin was high during hyponatremia, further supporting this diagnosis. Tolvaptan was effective in normalizing plasma sodium and enabling liberalization of fluids to ensure sufficient nutritional intake and weight gain and manage hunger. CONCLUSIONS: Hyponatremia due to SIADH is novel at presentation of a HH, and can be challenging to diagnose and manage. Successful management of hyponatremia in this case was achieved using tolvaptan.
Assuntos
Hiponatremia , Síndrome de Secreção Inadequada de HAD , Humanos , Tolvaptan/uso terapêutico , Hiponatremia/tratamento farmacológico , Hiponatremia/etiologia , Síndrome de Secreção Inadequada de HAD/diagnóstico , Antagonistas dos Receptores de Hormônios Antidiuréticos , Diuréticos , Benzazepinas , Convulsões , VasopressinasRESUMO
The application of pathophysiologic tenets has created significant changes in our approach to hyponatremia and hyponatremia-related conditions. This new approach incorporated the determination of fractional excretion (FE) of urate before and after the correction of hyponatremia and the response to isotonic saline infusion to differentiate the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) from renal salt wasting (RSW). FEurate simplified the identification of the different causes of hyponatremia, especially the diagnosis of a reset osmostat and Addison's disease. Differentiating SIADH from RSW has been extremely difficult because both syndromes present with identical clinical parameters, which could be overcome by successfully carrying out the difficult protocol of this new approach. A study of 62 hyponatremic patients from the general medical wards of the hospital identified 17 (27%) to have SIADH, 19 (31%) with reset osmostat, and 24 (38%) with RSW with 21 of these RSW patients presenting without clinical evidence of cerebral disease to warrant changing the nomenclature from cerebral to renal salt wasting. The natriuretic activity found in the plasma of 21 and 18 patients with neurosurgical and Alzheimer's disease, respectively, was later identified as haptoglobin-related protein without signal peptide (HPRWSP). The high prevalence of RSW creates a therapeutic dilemma of deciding whether to water-restrict water-logged patients with SIADH as compared to administering saline to volume-depleted patients with RSW. Future studies will hopefully achieve the following: 1. Abandon the ineffective volume approach; 2. Develop HPRWSP as a biomarker to identify hyponatremic and a projected large number of normonatremic patients at risk of developing RSW, including Alzheimer's disease; 3. Facilitate differentiating SIADH from RSW on the first encounter and improve clinical outcomes.
Assuntos
Doença de Alzheimer , Hiponatremia , Síndrome de Secreção Inadequada de HAD , Humanos , Hiponatremia/diagnóstico , Hiponatremia/etiologia , Hiponatremia/terapia , Síndrome de Secreção Inadequada de HAD/complicações , Síndrome de Secreção Inadequada de HAD/diagnóstico , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/complicações , Haptoglobinas , BiomarcadoresRESUMO
RATIONALE: Hyponatremia is a common electrolyte disorder in elderly critically ill patients, and it may be associated with poor outcomes, higher morbidity, and mortality. Syndrome of inappropriate antidiuresis (SIAD) is one of the main causes of hyponatremia, with an insidious onset that is highly misdiagnosed. Primary empty sella lesions are specific, mostly asymptomatic, and easily overlooked. SIAD combined with empty sella is much rarer in clinic, this article focuses on the diagnosis and management of an elderly patient with intractable hyponatremia secondary to syndrome of inappropriate antidiuresis complicated with empty sella. PATIENT CONCERNS: An 85-year-old male patient with severe pneumonia presented with progressive and intractable hyponatremia. DIAGNOSES: The patient had clinical signs of persistent hyponatremia, low plasma osmolality, elevated urinary sodium excretion, and hyponatremia that worsened with increased intravenous rehydration and was effective with appropriate fluid restriction. The diagnosis of SIAD combined with empty sella was made in combination with the findings of the pituitary and its target gland function. INTERVENTIONS: Numerous screenings were performed to clarify the cause of hyponatremia. His overall condition was poor due to recurrent episodes of hospital-acquired pneumonia. We treated with ventilation support, circulatory support, nutritional support, anti-infection, and continuous correction of electrolyte imbalance. OUTCOMES: His hyponatremia gradually improved through aggressive infection control, appropriate fluid restriction (intake controlled at 1500-2000mL/d), continuous electrolyte correction, supplementation with hypertonic salt solution, and potassium replacement therapy. LESSONS: Electrolyte disorders, especially hyponatremia, are very common in critically ill patients, but the etiology of hyponatremia is challenging to diagnose and treat, and timely attention and proper diagnosis of SIAD and individualized treatment are the significance of this article.
Assuntos
Síndrome da Sela Vazia , Hiponatremia , Síndrome de Secreção Inadequada de HAD , Pneumonia , Masculino , Humanos , Idoso , Idoso de 80 Anos ou mais , Hiponatremia/diagnóstico , Hiponatremia/etiologia , Hiponatremia/terapia , Síndrome de Secreção Inadequada de HAD/complicações , Síndrome de Secreção Inadequada de HAD/diagnóstico , Síndrome de Secreção Inadequada de HAD/terapia , Estado Terminal , Cloreto de Sódio , Síndrome da Sela Vazia/complicações , Pneumonia/complicações , Pneumonia/terapiaRESUMO
CONTEXT: Differential diagnosis of thiazide-associated hyponatremia (TAH) is challenging. Patients can either have volume depletion or a syndrome of inappropriate antidiuresis (SIAD)-like presentation. OBJECTIVE: To evaluate the impact of the simplified apparent strong ion difference in serum (aSID; sodium + potassium - chloride) as well as the urine chloride and potassium score (ChU; chloride - potassium in urine) in the differential diagnosis of TAH, in addition to assessment of fractional uric acid excretion (FUA). METHODS: Post hoc analysis of prospectively collected data from June 2011 to August 2013 from 98 hospitalized patients with TAH < 125 mmol/L enrolled at University Hospital Basel and University Medical Clinic Aarau, Switzerland. Patients were categorized according to treatment response in volume-depleted TAH requiring volume substitution or SIAD-like TAH requiring fluid restriction. We computed sensitivity analyses with ROC curves for positive predictive value (PPV) and negative predictive value (NPV) of aSID, ChU, and FUA in differential diagnosis of TAH. RESULTS: An aSID > 42 mmol/L had a PPV of 79.1% in identifying patients with volume-depleted TAH, whereas a value < 39 mmol/L excluded it with a NPV of 76.5%. In patients for whom aSID was inconclusive, a ChU < 15 mmol/L had a PPV of 100% and a NPV of 83.3%, whereas FUA < 12% had a PPV of 85.7% and a NPV of 64.3% in identifying patients with volume-depleted TAH. CONCLUSION: In patients with TAH, assessment of aSID, potassium, and chloride in urine can help identifying patients with volume-depleted TAH requiring fluid substitution vs patients with SIAD-like TAH requiring fluid restriction.
Assuntos
Hiponatremia , Síndrome de Secreção Inadequada de HAD , Humanos , Hiponatremia/induzido quimicamente , Hiponatremia/diagnóstico , Hiponatremia/terapia , Cloretos , Tiazidas/efeitos adversos , Síndrome de Secreção Inadequada de HAD/induzido quimicamente , Síndrome de Secreção Inadequada de HAD/diagnóstico , Potássio , Diagnóstico Diferencial , Cloreto de SódioRESUMO
BACKGROUND: the identification and minimization of hyponatraemia-inducing medication (HIM) usage is among the effective strategies for preventing hyponatraemia. However, the differential risk of severe hyponatraemia is unknown. OBJECTIVE: to evaluate the differential risk of severe hyponatraemia associated with newly started and concurrently used HIMs in older people. DESIGN AND SETTING: a case-control study using national claims databases. METHODS: we identified patients aged >65 years with severe hyponatraemia as those hospitalised with a primary diagnosis of hyponatraemia or who had received tolvaptan or 3% NaCl. A 1:20 matched control with the same visit date was constructed. Multivariable logistic regression was performed to assess the association of newly started or concurrently used HIMs comprising 11 medication/classes with severe hyponatraemia after covariate adjustment. RESULTS: among 47,766,420 older patients, we identified 9,218 with severe hyponatraemia. After adjusting for covariates, all HIM classes were found to be significantly associated with severe hyponatraemia. Compared with persistently used HIMs, newly started HIMs increased the likelihood of severe hyponatraemia for eight classes of HIMs, with the highest increase being observed for desmopressin (adjusted odds ratio: 3.82, 95% confidence interval: 3.01-4.85). Concurrent use increased the risk of severe hyponatraemia compared to that with individually administered HIMs: thiazide-desmopressin (4.86, 3.90-6.07), medications causing the syndrome of inappropriate anti-diuretic hormone secretion (SIADH)-desmopressin (2.65, 2.25-3.11), medications causing SIADH-thiazides (1.87, 1.75-1.98) and combination among medications causing SIADH (1.36, 1.28-1.45). CONCLUSIONS: in older adults, newly started and concurrently used HIMs increased the risk of severe hyponatraemia compared with persistently and singly used HIMs.