Syndrome of inappropriate

Syndrome of inappropriate antidiuretic hormone is defined by water retention, dilutional hyponatraemia and decreased volume of highly concentrated urine. There are several causes which can result in SIADH, neoplasms ectopic secreting AVP, ectopic release of AVP by various diseases or drugs, exogenous administration of AVP, desmopressin, lysipressin or large doses of OT (iatrogenic SLADH). 

In addition, several other organs, like the heart, ovaty, amnion, chorion, decidua, testis, epididymis and prostate, have been reported to synthesize OT, suggesting a paracrine role for this hormone in these tissues. Ectopic AVP production by lung cancer cells or other neoplasms has been described in humans, leading to the syndrome of inappropriate antidiuretic hormone secretion. 

SIADH Syndrome of inappropriate antidiuretic hormone TID Three times daily (ter in die)... 

Paraneoplastic syndromes commonly associated with lung cancers include cachexia, hypercalcemia, syndrome of inappropriate antidiuretic hormone secretion, and Cushing s syndrome. 

Causes of nonosmotic release of arginine vasopressin, commonly known as antidiuretic hormone, include hypovolemia decreased effective circulating volume as seen in patients with congestive heart failure nephrosis cirrhosis and syndrome of inappropriate antidiuretic hormone (SIADH) release. 

FIGURE 78-1. Diagnostic algorithm for the evaluation of hyponatremia. (CHF, congestive heart failure EABV, effective arterial blood volume SIADH, syndrome of inappropriate antidiuretic hormone UNa, urine sodium concentration Uosm, urine osmolality.)... 

While the dose-limiting toxicity for vinblastine usually is leukopenia, that for vincristine is most commonly neurotoxicity (58). Prominent manifestations of neurotoxicity are loss of the Achilles tendon reflex, paresthesias, loss of muscle strength (e.g., in the foot and wrist), and ataxia. Constipation and abdominal pain may occur and are thought to result, at least in part, from actions on the autonomic nervous system. Leukopenia and stomatitis are possible effects of vincristine treatment, but they occur relatively infrequently. Alopecia occurs with vincristine at a frequency comparable to that observed with vinblastine, and vincristine also is a potent tissue irritant. Vincristine may produce a syndrome of inappropriate secretion of antidiuretic hormone, and some manifestations of neurotoxicity, such as seizures, have been considered to be due to electrolyte disturbances associated with the relative excess of the antidiuretic hormone (58). 

Because of sensory neuropathy, deep pain is often experienced by patients given vincristine. Through involvement of the glossopharyngeal nerve, throat pain may occur, as may deep pain of almost any other area of the body (31,32). Neuropathic changes are not always peripheral. Hallucinations and overall mental status changes, such as depression and/or psychosis, are also rarely reported (31,32). Another CNS effect is the syndrome of inappropriate antidiuretic hormone secretion, which is a well-characterized side effect of vincristine (31,32). 

Loss of blood glucose control When a patient stabilized on any diabetic regimen is exposed to stress such as fever, trauma, infection, or surgery, a loss of control may occur. At such times, it may be necessary to discontinue the drug and give insulin. Disulfiram-like syncframe. A sulfonylurea-induced facial flushing or breathlessness reaction may occur when some sulfonylureas are administered with alcohol. Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) Water retention and dilutional hyponatremia have occurred after administration of sulfonylureas to type 2 diabetes patients, especially those with CHF or hepatic cirrhosis. 

SIADH syndrome of inappropriate antidiuretic hormone SL sublingual... 

Tetracyclines block ADH in the kidney and especially demeclocycline is used to treat the syndrome of inappropriate ADH secretion. 

Nephrogenic diabetes insipidus is due to resistance to action of vasopressin, and therefore DDAVP is not indicated, but some benefit may be gained by using thiazide diuretics or chlorpropamide. The syndrome of inappropriate antidiuretic hormone (SIADH) can be treated by using the antibiotic derivative demeclocycline to induce a state of vasopressin resistance and partial nephrogenic diabetes insipidus. 

Bouman WP Pinner G, lohnson H. Incidence of selective serotonin reuptake inhibitor (SSRI) induced hyponatraemia due to the syndrome of inappropriate antidiuretic hormone (SIADH) secretion in the elderly. Int 1 Geriatr Psychiatry 1998,13 12-15. 

Syndrome of inappropriate ADH secretion (SIADH) PO Initially, 900-1200 mg/day in 3-4 divided doses, then decrease dose to 600-900 mg/day in divided doses. 

Abbreviations CNS, central nervous system COX, cyclooxygenase Gl, gastrointestinal NSAlDs, nonsteroidal anti-inflammatory drugs SIADH, syndrome of inappropriate antidiuretic hormone secretion. From Pick DM, Cooper IW, Wade WE, et al Updating the Beers criteria for potentially inappropriate medication use in older adults Results of a U.S. consensus panel of experts. Arch Intern Med 2003 163 2716. 

Liu, B.A., Mittmann, N., Knowles, S.R., and Shear, N.H. (1996) Hyponatremia and the syndrome of inappropriate secretion of antidiuretic hormone associated with the use of selective serotonin reuptake inhibitors a review of spontaneous reports. CMAJ 155 519-527. 

BUN, blood urea nitrogen CBC, complete blood cell count CBZ, carbamazepine DVP, divalproex sodium EKG, electrocardiogram SIADH, syndrome of inappropriate secretion of antidiuretic hormone TSH, thyroid-stimulating hormone. 

Case reports have indicated an association between SSRIs and the syndrome of inappropriate secretion of antidiuretic hormone. Symptoms include lethargy, headache, hyponatremia, increased urinary sodium excretion, and hyperosmotic urine. Acute treatment of this syndrome should consist of discontinuation of the drug as well as restriction of fluid intake. Patients experiencing severe confusion, convulsions, or coma should receive intravenous sodium chloride. Elderly persons may he at a higher risk for developing this syndrome. 

Note. SIADH=syndrome of inappropriate secretion of antidiuretic hormone CBC=complete blood count TSH=thyroid-stimulating hormone ECG=electrocardiogram AST=aspartate aminotransaminase ALT=alanine aminolransaminase. 

The syndrome of inappropriate antidiuretic hormone secretion, with resultant hyponatremia, may be induced by carbamazepine treatment. Alcoholic patients may be at greater risk for hyponatremia. 

Amilohde and indomethacin are the most effective therapies for polyuria/polydipsia and syndrome of inappropriate ADH, respectively ( 77). 

Because CBZ can cause hyponatremia, it should be used cautiously in patients on a salt-restricted diet ( 373). Hyponatremia is rarely clinically significant when sodium values are above 125 mmol/L. Low sodium levels, as well as concomitant diuretic and lithium users, may predispose to the development of the syndrome of inappropriate ADH. Since CBZ enhances the effects of ADH, it can lead to impairment of free water clearance from the body. Older patients are at higher risk and should be closely monitored for this adverse effect which can be managed by dose reduction of CBZ. More severe cases, however, usually require switching to... 

Syndromes of inappropriate behaviour that can result from managers failing to manage one or more of these needs are... 

The syndrome of inappropriate antidiuretic hormone (SIADH) secretion is a condition in which secretion of ADH continues despite serum hypo-osmolarity. This results in fluid retention and hyponatremia that can lead to brain oedema, mental confusion and coma. The causes are hypothalamic-pituitary tumours or an ectopic vasopressin-secreting tumour. 

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