Summary Arginine-vasopressin is a hormone that plays an important part in circulatory and water homoeostasis. The three arginine-vasopressin-receptor subtypes—V1a, V1b, and V2—all belong to the large ...rhodopsin-like G-protein-coupled receptor family. The vaptans are orally and intravenously active non-peptide vasopressin receptor antagonists that are in development. Relcovaptan is a selective V1a-receptor antagonist, which has shown initial positive results in the treatment of Raynaud's disease, dysmenorrhoea, and tocolysis. SSR-149415 is a selective V1b-receptor antagonist, which could have beneficial effects in the treatment of psychiatric disorders. V2-receptor antagonists—mozavaptan, lixivaptan, satavaptan, and tolvaptan—induce a highly hypotonic diuresis without substantially affecting the excretion of electrolytes (by contrast with the effects of diuretics). These drugs are all effective in the treatment of euvolaemic and hypervolaemic hyponatraemia. Conivaptan is a V1a/V2 non-selective vasopressin-receptor antagonist that has been approved by the US Food and Drug Administration as an intravenous infusion for the inhospital treatment of euvolaemic or hypervolaemic hyponatraemia.
Hyponatraemia, defined as a serum sodium concentration <135 mmol/l, is the most common disorder of body fluid and electrolyte balance encountered in clinical practice. It can lead to a wide spectrum ...of clinical symptoms, from subtle to severe or even life threatening, and is associated with increased mortality, morbidity and length of hospital stay in patients presenting with a range of conditions. Despite this, the management of patients remains problematic. The prevalence of hyponatraemia in widely different conditions and the fact that hyponatraemia is managed by clinicians with a broad variety of backgrounds have fostered diverse institution- and speciality-based approaches to diagnosis and treatment. To obtain a common and holistic view, the European Society of Intensive Care Medicine (ESICM), the European Society of Endocrinology (ESE) and the European Renal Association - European Dialysis and Transplant Association (ERA-EDTA), represented by European Renal Best Practice (ERBP), have developed the Clinical Practice Guideline on the diagnostic approach and treatment of hyponatraemia as a joint venture of three societies representing specialists with a natural interest in hyponatraemia. In addition to a rigorous approach to methodology and evaluation, we were keen to ensure that the document focused on patient-important outcomes and included utility for clinicians involved in everyday practice.
Adult-onset Still's disease (AOSD) is a rare autoinflammatory disorder that can lead to a cytokine storm, causing a range of symptoms. Acute intestinal pseudo-obstruction is another rare condition ...that results in intestinal obstruction without anatomical cause. Although the two conditions are rarely reported together, we present the case of a 62-year-old male who developed acute intestinal pseudo-obstruction in the context of an AOSD flare. This led to severe hypokalaemia and a critical condition. Other symptoms included a high-spiking fever lasting for weeks, polyarthralgias and a typical salmon-coloured rash. After ruling out other potential causes, the patient was diagnosed with AOSD. Our findings suggest that the cytokine storm associated with this disease triggered the acute intestinal pseudo-obstruction and life-threatening hypokalaemia, establishing a causal relationship. Only four other cases of AOSD complicated by intestinal pseudo-obstruction have been reported, and this is the first to present with life-threatening hypokalaemia. This case serves as a crucial reminder that, despite being a diagnosis of exclusion, Still's disease should be considered as a potential cause of intestinal pseudo-obstruction, as prompt recognition and treatment of the underlying cause is crucial in managing this potentially life-threatening condition.
Acute intestinal pseudo-obstruction is one of the systemic complications that can occur in autoinflammatory diseases such as AOSD, although it has rarely been described.If AOSD presents with abdominal presentation, such as acute intestinal pseudo-obstruction, then amyloidosis should always be carefully considered.
Vaptans (vasopressin V(2)-receptor antagonists) are a new approach for the treatment of hyponatremia. However, their indications remain to be determined, and their benefit compared with that of the ...usual treatments for the syndrome of inappropriate antidiuretic hormone secretion (SIADH) have not been evaluated. This prospective, long-term study compared the efficacy, tolerability, and safety of two oral vaptans with those of oral urea in patients with SIADH.
Patients with chronic SIADH of various origins were treated first with vaptans for 1 year. After an 8-day holiday period, they received oral urea for an additional 1-year follow-up. Serum sodium was measured every 2 months, and drug doses were adjusted accordingly.
Thirteen participants were initially included in the study (serum sodium, 125±3 mEq/L); 12 completed the 2-year treatment period. Treatment with vaptans (satavaptan, 5-50 mg/d, n=10; tolvaptan, 30-60 mg/day, n=2) increased natremia (serum sodium, 135±3 mEq/L) during the 1-year vaptan period without escape. Hyponatremia recurred in the 12 participants when vaptans were stopped (holiday period). Urea improved the natremia with the same efficacy (serum sodium, 135±2 mEq/L) as vaptans during the 1-year urea treatment period. One participant treated with tolvaptan withdrew from the study early because of excessive thirst. Another patient receiving urea developed hypernatremia without complications.
Urea has efficacy similar to that of vaptans for treatment of chronic SIADH. Tolerance is generally good for both agents.
Spontaneous periodic hypothermia (SPH) is an exceptionally rare condition characterised by paroxysmal episodes of spontaneous hypothermia. While commonly associated with Shapiro syndrome, which ...includes SPH, hyperhidrosis and agenesis of the corpus callosum, there are also cases of SPH that do not exhibit these defining characteristics, known as 'Shapiro syndrome variant'. These variants may present with diverse brain imaging findings but no agenesis of the corpus callosum, suggesting different potential aetiologies. Notably, the association of SPH with epilepsy has only been reported in a few cases, and confirming epileptic activity in the context of SPH remains a challenge. In line with this, our report presents two exceptional cases of SPH without significant brain malformation, where we successfully confirmed the presence of epilepsy. The confirmation of epilepsy in these cases is particularly noteworthy, as it adds to the limited documentation of SPH cases with confirmed epilepsy. These findings contribute valuable insights into the association between SPH and epilepsy, enhancing our understanding of this rare condition. Our report also addresses the broader clinical presentations and the physiopathological mechanisms of SPH. By providing comprehensive insights into these aspects, we aim to advance the existing literature and improve our understanding of SPH and its association with epilepsy.
SPH is a rare condition, characterised by paroxysmal episodes of spontaneous hypothermia.A dysregulation of the hypothalamic thermostat is thought to be involved in the pathogenesis.Epilepsy may contribute to the pathogenesis of SPH, potentially by involving the hypothalamus.
Abrupt osmotic changes during rapid correction of chronic hyponatremia result in demyelinative brain lesions, but the sequence of events linking rapid osmotic changes to myelin loss is not yet ...understood. Here, in a rat model of osmotic demyelination syndrome, we found that massive astrocyte death occurred after rapid correction of hyponatremia, delineating the regions of future myelin loss. Astrocyte death caused a disruption of the astrocyte-oligodendrocyte network, rapidly upregulated inflammatory cytokines genes, and increased serum S100B, which predicted clinical manifestations and outcome of osmotic demyelination. These results support a model for the pathophysiology of osmotic brain injury in which rapid correction of hyponatremia triggers apoptosis in astrocytes followed by a loss of trophic communication between astrocytes and oligodendrocytes, secondary inflammation, microglial activation, and finally demyelination.
Osmotic demyelination syndrome is a devastating neurologic disorder often seen after the rapid correction of chronic hyponatremia. The permeability of the blood–brain barrier is increased in ...experimental osmotic demyelination, and some have suggested that corticosteroids protect against this disorder by keeping the permeability of the blood–brain barrier low. We previously reported that re-lowering of the serum sodium after rapid correction of chronic hyponatremia was beneficial if performed early in the course (12 to 24h). Here we compared mortality, blood–brain barrier permeability, and microglial activation in rats after the rapid correction of chronic hyponatremia. We studied three groups of rats after correction of chronic hyponatremia: and treated them with sodium chloride, with or without dexamethasone; or with sodium chloride followed by re-induction of hyponatremia. We found that treatment with dexamethasone or re-induction of hyponatremia effectively prevented the opening of the blood–brain barrier, reduced neurological manifestations, and decreased microglial activation; however, only re-induction of hyponatremia resulted in a significant decrease in mortality 5 days after the correction of chronic hyponatremia. Restoring the permeability of the blood–brain barrier to normal levels did not decrease mortality. Our results suggest that after inadvertent rapid correction of hyponatremia, treatment options should favor re-lowering serum sodium. The increased permeability of blood–brain barrier seen in osmotic demyelination syndrome may not be a primary pathophysiologic insult of this syndrome.
The effects of satavaptan (SR121463B), a novel long-acting orally active vasopressin V(2)-receptor antagonist, were investigated in patients with the syndrome of inappropriate antidiuretic hormone ...secretion (SIADH). In the first part of this randomized, double-blind study, 34 patients first were treated with satavaptan (versus placebo) for up to 5 d and then during 23 d of open-label dosage-adjustment period. In the second part of the study, long-term efficacy and safety of satavaptan was assessed in an open-label trial during at least 12 mo. Mean (+/-SD) serum sodium (SNa) levels before treatment were 127 +/- 2 mmol/L (placebo, n = 8), 125 +/- 6 mmol/L (25 mg, n = 14), and 127 +/- 5 mmol/L (50 mg, n = 12). Responders (patients SNa levels normalized or increased by at least 5 mmol/L from baseline during the double-blind period) were 79% in the 25-mg group (SNa 136 +/- 3 mmol/L; P = 0.006), 83% in the 50-mg group (SNa 140 +/- 6 mmol/L; P = 0.005), and 13% in the placebo group (SNa 130 +/- 5 mmol/L). No drug-related serious adverse events were recorded. During the long-term treatment, 15 of 18 enrolled patients achieved 6 mo and 10 achieved 12 mo of treatment. The SNa response was maintained during this time with a good tolerance. The new oral vasopressin V(2)-receptor antagonist satavaptan adequately corrects mild or moderate hyponatremia in patients with SIADH and has a good safety profile.
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