Drug-induced syndrome of inappropriate antidiuretic hormone secretion

Management of nephrotoxicity of chemotherapy and targeted agents: 2020

Nephrotoxic effects of certain chemotherapeutic agents such as cisplatin and ifosfamide has been well documented and these effects are carefully managed by oncologists during their usage. The introduction of targeted agents has added a new challenge to cancer management as their nephrotoxic effects and associated management is in the process of being adopted by oncologists. This work is a compilation of side effects on the renal system due to various chemotherapeutic, immunotherapeutic and targeted agents followed by their recommended management.

Copeptin, a surrogate marker of arginine8 vasopressin, has no ability to modulate human and mouse gastric motility

Copeptin, a glycosylated peptide fragment derived from the C-terminal region of the precursor of arginine⁸ vasopressin (AVP), is co-secreted with AVP in equimolar amounts. Elevated plasma AVP modulates gastric motility so we investigated whether copeptin had a similar effect. Copeptin (10^-9-10^-7M), and AVP (10^-12-10^-5M), were evaluated for their ability to modulate spontaneous and electrically-evoked (EFS) contractions of human proximal and distal gastric circular muscle in vitro. Similar experiments were performed on the mouse stomach and we re-examined the published effect of copeptin on the mouse aorta. In the presence of tetrodotoxin (10^-6M), atropine (10^-6M) and L-NAME (3 × 10^-4M), human proximal and distal stomach muscle contracted spontaneously and rhythmically as did mouse distal stomach. Copeptin (10^-9-10^-7M), had no effect on baseline muscle tone or myogenic spontaneous contractions of either human or mouse stomach. However, AVP concentration-dependently increased tone, amplitude and frequency of contractions in both regions of human stomach with similar potency (pEC₅₀ 9.0-9.5; n = 4) and threshold concentration (10^-11-10^-10M). AVP was similarly active in the mouse stomach. EFS-evoked cholinergic contractions (human and mouse) were unaffected by both peptides EFS-evoked relaxations of mouse stomach were unaffected by copeptin. In sub-maximally contracted mouse aorta the elevated tone was unaffected by copeptin (10^-7M) (cf. previously published study) but was reduced by carbachol (10^-6M) and sodium nitroprusside (10^-3M). We conclude that in contrast to AVP, copeptin over a concentration range reported in the plasma has no direct ability to modulate the motility of the human and mouse stomach.

Selective Serotonin Reuptake Inhibitor-Induced Hyponatremia and the Plastic Surgery Patient

Cosmetic plastic surgery procedures continue to increase in frequency, and a greater number of them now occur outside of an acute-care hospital setting. In addition, antidepressant use is also rising, with a greater number of patients taking selective serotonin reuptake inhibitors to aid in a variety of mood and anxiety disorders. Americans spend more than $86 billion each year on antidepressants, as 34 million people in the United States are taking at least one of these medications. Many side effects of selective serotonin reuptake inhibitors are well known and not clinically relevant to practicing surgeons. Hyponatremia, however, is a well-documented side effect of these medications that has received relatively little attention in the surgical literature. Postoperative hyponatremia results because of a decrease of antidiuretic hormone suppression that occurs with selective serotonin reuptake inhibitor administration. Here, the authors first review the literature reporting hyponatremia with selective serotonin reuptake inhibitor use. The authors then present two cases of severe postoperative hyponatremia after plastic surgery operations. The authors propose that patients using selective serotonin reuptake inhibitors, especially elderly patients and those undergoing procedures with expected large fluid shifts, should be tested preoperatively and postoperatively for serum sodium levels so that a diagnosis of hyponatremia may be made early and treated before a catastrophic event.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Cyclophosphamide-induced severe acute hyponatremic encephalopathy in patients with breast cancer: report of two cases

Background

Cyclophosphamide is an alkylating agent widely used in antineoplastic and immunosuppressive therapies. Symptomatic hyponatremia can be a rare but life-threatening complication in patients treated with cyclophosphamide.

Case Presentations

We report 2 patients who presented with severe acute hyponatremic encephalopathy after receiving their first cycles of a low-dose cyclophosphamide-containing regimen for breast cancer. In case 1, a 58-year-old female received the combination of docetaxel and cyclophosphamide, and in case 2, a 56-year-old female received the combination of doxorubicin and cyclophosphamide. Both patients recovered after correction of their serum sodium concentration without neurological deficits. Future cycles of chemotherapy were well tolerated without recurrence of hyponatremia after cyclophosphamide was discontinued from the respective regimens.

Conclusion

Clinicians must always keep in mind that acute hyponatremic encephalopathy can be induced by low-dose cyclophosphamide.

Amiodarone induced hyponatremia masquerading as syndrome of inappropriate antidiuretic hormone secretion by anaplastic carcinoma of prostate

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is one of the most common causes of hyponatremia. The usual causes are malignancies, central nervous system, pulmonary disorders, and drugs. Amiodarone is a broad spectrum antiarrhythmic agent widely used in the management of arrhythmias. The different side effects include thyroid dysfunction, visual disturbances, pulmonary infiltrates, ataxia, cardiac conduction abnormalities, drug interactions, corneal microdeposits, skin rashes, and gastrointestinal disturbances. SIADH is a rare but lethal side effect of amiodarone. We describe a 62-year-old male who was suffering from advanced prostatic malignancy, taking amiodarone for underlying heart disease. He developed SIADH which was initially thought to be paraneoplastic in etiology, but later histopathology refuted that. This case emphasizes the importance of detailed drug history and the role of immunohistochemistry in establishing the diagnosis and management of hyponatremia due to SIADH.

Disorders of sodium and water balance

Dysnatremias occur simultaneously with disorders in water balance. The first priority is to correct dehydration; once the patient is euvolemic, the sodium level can be reassessed. In unstable patients with hyponatremia, the clinician should rapidly administer hypertonic saline. In unstable patients with hypernatremia, the clinician should administer isotonic intravenous fluid. In stable patients with either hyponatremia or hypernatremia, the clinician should aim for correction over 24 to 48 hours, with the maximal change in serum sodium between 8 to 12 mEq/L over the first 24 hours. This rate of correction decreases the chances of cerebral edema or osmotic demyelination syndrome.

Hyponatremia - a rare but serious complication of amiodarone: a case report and review of the literature

Introduction

Hyponatremia secondary to the syndrome of inappropriate antidiuretic hormone secretion (SIADH) during amiodarone therapy is a rare but potentially lethal adverse effect. We report a case of severe hyponatremia associated with amiodarone, and discuss its clinical implications.

Case Report

An 84-year-old Caucasian man with a past medical history of hypertension and diabetes was admitted to the hospital with a non-ST elevation myocardial infarction. He underwent coronary artery bypass graft and developed atrial fibrillation on postoperative day 2. A loading dose of amiodarone followed by a maintenance dose was started. The serum sodium level was 136 mmol/l at discharge and subsequently decreased to 105 mmol/l 11 days later, at which time the patient represented with altered mental status. The diagnosis of SIADH was made based on euvolemic hypoosmotic hyponatremia, lack of any other medication known to cause SIADH and urine that was less than maximally dilute. The serum sodium increased gradually to 123 mmol/l after 36 h of treatment with hypertonic saline, demeclocycline and fluid restriction.

Conclusion

SIADH-induced hyponatremia associated with amiodarone occurs rarely. Since severe hyponatremia is associated with significant neurological damage and mortality, clinicians should carefully monitor serum sodium during amiodarone therapy.

Ecstasy (3,4-methylenedioxymethamphetamine)-induced inappropriate antidiuretic hormone secretion

3,4-Methylenedioxymethamphetamine (MDMA), popularly known as the illicit drug "Ecstasy," is an amphetamine derivative that has become widely abused throughout the United States and other industrialized nations. 3,4-Methylenedioxymethamphetamine has an undeserved reputation as a "safe" drug among its users, but MDMA shares the toxicity profile of other amphetamines. Its use may result in lethal cardiovascular, hepatic, metabolic, or neurological toxicity. The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a unique toxicity that may occur after isolated MDMA use. Although the phenomenon is well described in adults, reports of MDMA-induced SIADH and symptomatic hyponatremia in children are rare. We describe a 13-year-old girl who experienced MDMA-induced SIADH with symptomatic hyponatremia. Toxicity of MDMA, in particular, the pathophysiology and treatment of MDMA-induced hyponatremia, is discussed.

Intermittent severe, symptomatic hyponatraemia due to the nephrogenic syndrome of inappropriate antidiuresis

A 20-year-old fit male soldier presented on two separate occasions 16 months apart with severe, symptomatic hyponatraemia and a clinical and biochemical picture consistent with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). In the intervening period, repeated plasma sodium values were in the reference range. Intensive investigation failed to reveal a cause for SIADH that was initially considered idiopathic. The description of a family comprising several adults with intermittent or water load induced-hyponatraemia associated with an activating mutation in the arginine vasopressin (AVP) receptor type 2 (AVPR2) raised the question of whether our patient could have a similar ‘nephrogenic syndrome of inappropriate antidiuresis’. Mutational screening of AVPR2 in our patient revealed a single missense mutation (R137C) in the second intracellular loop, which has been associated with constitutive activation of the AVPR2. In conclusion, adults with intermittent, severe hyponatraemia may have a constitutively activating mutation in the AVPR2 with resultant nephrogenic syndrome of inappropriate antidiuresis. Patients with idiopathic SIADH, particularly those with unmeasurable circulating AVP concentrations, should be considered for mutational screening of AVPR2.

Copeptin: clinical use of a new biomarker

Arginine vasopressin (AVP) is a key hormone in the human body. Despite the clinical relevance of AVP in maintaining fluid balance and vascular tone, measurement of mature AVP is difficult and subject to preanalytical errors. Recently, copeptin, a 39-amino acid glycopeptide that comprises the C-terminal part of the AVP precursor (CT-proAVP), was found to be a stable and sensitive surrogate marker for AVP release, analogous to C-peptide for insulin. Copeptin measurement has been shown to be useful in various clinical indications, including the diagnosis of diabetes insipidus and the monitoring of sepsis and cardiovascular diseases. Here we review recent findings regarding the relationship between AVP and copeptin, and affirm the value of AVP as a surrogate marker for AVP.

Patterns of Ecstasy-Associated Hyponatremia in California

STUDY OBJECTIVE

We describe the clinical characteristics of patients with ecstasy- (3,4-methylenedioxymethamphetamine [MDMA]) associated hyponatremia (serum sodium level <130 mmol/L) reported to the California Poison Control System during a 5-year period and determine whether a sex difference exists among patients with ecstasy-associated hyponatremia and hyponatremia-associated adverse outcomes.

METHODS

We performed a retrospective review of cases involving ecstasy intoxication reported to the California Poison Control System and recorded in its computerized database from January 1, 2000, through October 9, 2005. We excluded cases that did not involve MDMA exposure or in which there were no symptoms or were minimal effects only. Confirmation of exposure to MDMA was based on history of use and, when available, urine toxicology testing results positive for MDMA or amphetamine derivatives. Hyponatremia was defined as a measured serum sodium level less than 130 mmol/L.

RESULTS

A total of 1,436 cases potentially involving ecstasy were reported to the California Poison Control System during the 5-year study period, of which 891 were excluded according to the criteria described above. Of the 545 cases that met inclusion criteria, 296 (54.3%) were women and 249 (45.7%) were men. There were 188 cases (34.5%) with a documented serum sodium level, of which 73 (38.8%) reported hyponatremia (Na <130 mmol/L). Of the 73 subjects with hyponatremia, 55 (75.3%) were women and 18 (24.7%) men; of the 115 nonhyponatremic subjects, 50 (43.5%) were women and 65 (56.5%) were men. Among patients with a documented serum sodium level, female sex was associated with increased odds of hyponatremia (odds ratio [OR] 4.0; 95% confidence interval [CI] 2.1 to 7.6). Among women, those with hyponatremia demonstrated increased odds of coma (OR 3.9; 95% CI 1.2 to 12.9), whereas among men, no increased odds of hyponatremia-associated coma were observed (OR 0.8; 95% CI 0.15 to 4.0).

CONCLUSION

Female sex was associated with increased odds of hyponatremia and increased odds of hyponatremia-associated coma among persons with ecstasy intoxication and a documented serum sodium level reported to the California Poison Control System from 2000 to 2005. Multiple potential confounders, including spectrum bias, incomplete laboratory data, and individual differences in study subject characteristics, prevent determination of causality about sex differences in the incidence of ecstasy-associated hyponatremia and its complications.

Clinically important drug-disease interactions and their prevalence in older adults

BACKGROUND

Older adults may have decreased homeostatic reserve, have multiple chronic diseases, and take multiple medications. Therefore, they are at risk for adverse outcomes after receiving a drug that exacerbates a chronic disease.

OBJECTIVES

The aims of this study were to compile a list of clinically important drug-disease interactions in older adults, obtain the consensus of a multidisciplinary panel of geriatric health care professionals on these interactions, and determine the prevalence of these interactions in a sample of outpatients.

METHODS

This analysis included a 2-round modified Delphi survey and cross-sectional study. Possible drug-disease interactions in patients aged > or =65 years were identified through a search of the English-language literature indexed on MEDLINE and International Pharmaceutical Abstracts (1966-July 2004) using terms that included drug-disease interaction, medication errors, and inappropriate prescribing. Nine health care professionals with expertise in geriatrics (2 geriatricians, 7 geriatric clinical pharmacist specialists) were selected based on specialty training and continuing clinical work in geriatrics, academic appointments, and geographic location. The panel rated the importance of the potential drug-disease interactions using a 5-point Likert scale (from 1 = definitely not serious to 5 = definitely serious). Consensus on a drug-disease interaction was defined as a lower bound of the 95% CI > or =4.0. The prevalence of drug-disease interactions was determined by applying the consensus criteria to a convenience sample of frail older veterans at hospital discharge who were enrolled in a health services intervention trial.

RESULTS

The panel reached consensus on 28 individual drug-disease interactions involving 14 diseases or conditions. Overall, 205 (15.3%) of the 1340 veterans in the sample had > or =1 drug-disease interaction. The 2 most common drug-disease interactions were use of first-generation calcium channel blockers in patients with congestive heart failure and use of aspirin in patients with peptic ulcer disease (both, 3.7%).

CONCLUSIONS

A survey of multidisciplinary geriatric health care professionals resulted in a concise consensus list of clinically important drug-disease interactions in older adults. Further research is needed to examine the impact of these drug-disease interactions on health outcomes and their applicability as national measures for the prevention of drug-related problems.

Inappropriate Secretion of Antidiuretic Hormone: A Rare Complication after Carotid Endarterectomy

The syndrome of inadequate secretion of the antidiuretic hormone (SIADH) is a very rare complication after carotid endarterectomy, characterized by hyponatremia, decrease of serum osmolarity as well as an increase in urinary osmolarity. We report the case of an 80-year-old woman who developed, 24 hours after the surgery, a picture of drowsiness and lethargy without neurological focality. The diagnosis of SIADH was suspected. We conclude that is important to have in mind this clinical entity in the differential diagnosis of non-focal neurological deficit after carotid endarterectomy.

A Rare Case of Combined Syndrome of Inappropriate Antidiuretic Hormone Secretion and Fanconi Syndrome in an Elderly Woman

An 83-year-old Japanese woman was admitted to our hospital with severe hyponatremia (sodium, 108 mEq/L [108 mmol/L]), hypokalemia, hypochloridemia, hypocalcemia, hypophosphatemia, and hypouricemia. Despite low plasma osmolarity (232 mOsm/kg [232 mmol/kg]), urine osmolarity (320 mOsm/kg) was greater than that of plasma, and she had increased urinary sodium excretion (88 mEq/L [88 mmol/L]) and an unsuppressed high plasma level of antidiuretic hormone (ADH; 5.5 pg/mL [5.1 pmol/L]). These findings indicated that she had syndrome of inappropriate ADH secretion (SIADH). In addition, she had a generalized reabsorption defect of the proximal tubules, including decreased tubular reabsorption of phosphate, increased fractional excretion of uric acid, glycosuria despite a normal blood glucose level, and panaminoaciduria. Thus, combined SIADH and Fanconi syndrome was diagnosed. The cause was thought to be the antidepressant paroxetine, which is a selective serotonin reuptake inhibitor (SSRI). Several of the abnormal values resolved within 1 week after discontinuation of this drug. Although the precise mechanism responsible was not elucidated, we report an extremely rare case of combined SIADH and Fanconi syndrome, probably caused by short-term SSRI therapy.

Disorders of water imbalance

Disorders of water imbalance manifest as hyponatremia and hypernatremia. To diagnose these disorders, emergency physicians must maintain a high index of suspicion, especially in the high-risk patient, because clinical presentations may be nonspecific. With severe water imbalance, inappropriate fluid resuscitation in the emergency department may have devastating neurological consequences. The rate of serum sodium concentration correction should be monitored closely to avoid osmotic demyelination syndrome in hyponatremic patients and cerebral edema in hypernatremic patients.

The "ecstasy" hangover: hyponatremia due to 3,4-methylenedioxymethamphetamine

3,4-Methylenedioxymethamphetamine (MDMA, or "ecstasy") has gained an undeserved reputation as a "safe" drug among its users. However, hyperthermia, rhabdomyolysis, hepatotoxicity, disseminated intravascular coagulation, long-term serotonergic neurotoxicity, and death are all associated with MDMA use. Hyponatremia is also reported, and its manifestations are frequently delayed several hours after the drug is ingested. The etiology of this hyponatremia is unclear; both the syndrome of inappropriate antidiuretic hormone release (SIADH) and free-water intoxication are advanced as explanations. We describe a 19-year-old female who presented to the emergency department with altered mental status 1 day after using MDMA. Her initial serum sodium was 121 mmol/L, and computerized tomography (CT) of her head demonstrated cerebral edema. She was treated with hypertonic saline and fluid restriction, and her serum sodium increased to 132 mmol/L over the next 24 hours. She regained consciousness completely within 48 hours of presentation and recovered uneventfully. MDMA toxicity, particularly the pathophysiology and treatment of MDMA-induced hyponatremia, are discussed.

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) induced by amiodarone: a report on two cases

BACKGROUND

Amiodarone is an effective antiarrhythmic agent for life-threatening arrhythmias but has some noncardiac toxicity. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) induced by amiodarone during long-term therapy seems to be rare among adverse effects.

SUBJECTS AND RESULTS

We report on two elderly cases that developed hyponatremia caused by SIADH occurring during the initial loading period of amiodarone therapy. Both cases improved within 3 weeks after reduction of the dose, although amiodarone was continued.

CONCLUSIONS

Amiodarone-induced SIADH may occur during the initial loading period, and it may be improved by reduction of the dose without discontinuation of the drug.

Severe symptomatic hyponatremia during citalopram therapy

Hyponatremia secondary to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is an uncommon complication of treatment with the new class of antidepressant agents, the selective serotonin reuptake inhibitors (SSRIs). Most of the reported cases were associated with fluoxetine; only 2 have previously been described in association with citalopram. We describe an elderly woman who presented with severe symptomatic hyponatremia caused by the SIADH during therapy with citalopram. Because the use of SSRIs is becoming more popular among elderly depressed patients, the present case and the other 2 reported previously emphasize the need for greater awareness of the development of this serious and potentially fatal complication also in association with citalopram therapy and suggest that serum sodium levels should be monitored closely in elderly patients during treatment with citalopram.