Chronic Hyponatremia: The Role of Reset Osmostat in Patients with Suspected SIAD.

Background: Hyponatremia is common, particularly among the elderly. Reset osmostat (RO) serves as an alternative diagnosis to the syndrome of inappropriate antidiuresis (SIAD). There is limited information available regarding the prevalence of RO in outpatient clinics and hospital wards. The water-diluting test is considered the gold standard for the diagnosis of RO. The recent identification of copeptin provides an additional diagnostic marker alongside the utilization of fractional uric acid excretion. Methods: This single-center, prospective, observational study involved eight patients undergoing a water-diluting test over a study period of 2 years. Results: Reset osmostat was diagnosed in 50% of cases, while SIAD was confirmed in one patient. The tests were inconclusive for the remaining three patients. Conclusions: Our findings suggest that reset osmostat, despite its rarity, is a plausible diagnosis in chronic hyponatremia. The relevance of copeptin could not be confirmed in this study. Moreover, fractional uric acid excretion might be as effective as the water-diluting test in diagnosing reset osmostat.

Lithium-induced NDI: acetazolamide reduces polyuria but does not improve urine concentrating ability.

Lithium is the mainstay treatment for patients with bipolar disorder, but it generally causes nephrogenic diabetes insipidus (NDI), a disorder in which the renal urine concentrating ability has become vasopressin insensitive. Li-NDI is caused by lithium uptake by collecting duct principal cells and downregulation of aquaporin-2 (AQP2) water channels, which are essential for water uptake from tubular urine. Recently, we found that the prophylactic administration of acetazolamide to mice effectively attenuated Li-NDI. To evaluate whether acetazolamide might benefit lithium-treated patients, we administered acetazolamide to mice with established Li-NDI and six patients with a lithium-induced urinary concentrating defect. In mice, acetazolamide partially reversed lithium-induced polyuria and increased urine osmolality, which, however, did not coincide with increased AQP2 abundances. In patients, acetazolamide led to the withdrawal of two patients from the study due to side effects. In the four remaining patients acetazolamide did not lead to clinically relevant changes in maximal urine osmolality. Urine output was also not affected, although none of these patients demonstrated overt lithium-induced polyuria. In three out of four patients, acetazolamide treatment increased serum creatinine levels, indicating a decreased glomerular filtration rate (GFR). Strikingly, these three patients also showed a decrease in systemic blood pressure. All together, our data reveal that acetazolamide does not improve the urinary concentrating defect caused by lithium, but it lowers the GFR, likely explaining the reduced urine output in our mice and in a recently reported patient with lithium-induced polyuria. The reduced GFR in patients prone to chronic kidney disease development, however, warrants against application of acetazolamide in Li-NDI patients without long-term (pre)clinical studies.

Goodpasture's Syndrome with Negative Anti-glomerular Basement Membrane Antibodies.

A young male patient with rapidly progressive and life-threatening pulmonary haemorrhage due to anti-glomerular basement membrane (anti-GBM) antibody disease without renal involvement repeatedly tested negative for serum anti-GBM antibodies. Although rare, anti-GBM antibody disease should be considered in the differential diagnosis in patients with life-threatening pulmonary haemorrhage due to isolated diffuse alveolar haemorrhage. Enzyme-linked-immunosorbent assay (ELISA) testing for anti-GBM antibodies in anti-GBM antibody disease can give false-negative results. A negative serum anti-GBM antibody test is therefore insufficient to exclude the diagnosis. Thus, a kidney or lung biopsy should be considered in any case with a high clinical suspicion but negative anti-GBM antibody test to confirm or rule out the diagnosis. LEARNING POINTS: Diffuse alveolar haemorrhage (DAH) is a life-threatening disorder caused by severe damage due to injury or inflammation of the alveolar-capillary basement membrane.Anti-GBM antibody disease is a rare autoimmune disorder with circulating autoantibodies directed against the alpha-3 chain[Q2] of type VI collagen of the glomerular and/or alveolar basement membrane which may result in oliguric acute kidney failure due to rapidly progressive glomerulonephritis with or without DAH (commonly referred to as Goodpasture's syndrome).A kidney or lung biopsy should be considered to confirm or rule out the diagnosis if there is a high clinical suspicion but the anti-GBM antibody test is negative; prompt diagnosis and initiation of plasmapheresis, cyclophosphamide and prednisone therapy is essential.

Outcome of first line systemic treatment in elderly compared to younger patients with metastatic colorectal cancer: a retrospective analysis of the CAIRO and CAIRO2 studies of the Dutch Colorectal Cancer Group (DCCG).

BACKGROUND: Metastatic colorectal cancer (CRC) is predominantly a disease of the elderly, therefore the current standards should be evaluated in this population. MATERIAL AND METHODS: We evaluated in different age groups the outcome in terms of median overall and progression-free survival, response rate, disease control rate, relative dose intensity (RDI), tolerability, and global quality of life (QoL) of first-line capecitabine monotherapy (CAP) versus capecitabine + irinotecan (CAPIRI) and capecitabine + oxaliplatin + bevacizumab (CAPOX + BEV) in the CAIRO and CAIRO2 study, respectively. Patients were categorized into three age groups: age > 75, 70-75 and < 70 years. RESULTS: Clinical outcomes were not significantly different among age groups, with the exception of a higher response rate from CAP treatment in the elderly. Elderly patients treated with CAPOX + BEV showed a trend towards a worse median overall survival compared to younger patients. Only treatment with CAP resulted in a higher incidence of grade 3-4 toxicity and a lower RDI in elderly versus younger patients. Treatment with CAP and CAPOX + BEV in elderly patients was significantly more often discontinued due to toxicity instead of progression to disease compared to younger patients. The increase in global QoL was comparable for the three age groups for each treatment regimen. CONCLUSION: We did not observe significant differences in survival outcomes between elderly and younger metastatic CRC patients with three different first-line systemic treatment regimens. Our data suggest that initial dose reduction of CAP monotherapy may be indicated in elderly patients.

[An unknown but potentially serious side effect of proton pump inhibitors: hypomagnesaemia]. / Een onbekende, maar potentieel ernstige bijwerking van protonpompremmers: hypomagnesiëmie.

Long-term use of proton pump inhibitors can lead to serious hypomagnesaemia. Intestinal magnesium absorption takes place by passive paracellular and active transcellular transport. It has been hypothesized that proton pump inhibitors impair the active transcellular magnesium transport. The resulting hypomagnesaemia may cause hypoparathyroidism, hypocalcaemia and hypokalaemia. Proton pump inhibitor-induced hypomagnesaemia is reversible: it resolves when proton pump inhibitors are stopped. The indication for long-term proton pump inhibitor treatment should be evaluated periodically.

Off-label use of drugs in pain medicine and palliative care: an algorithm for the assessment of its safe and legal prescription.

Off-label medication use is common practice, particularly in difficult to treat patients who have already tried commonly accepted medication unsuccessfully. Health authorities try to regulate this practice to protect the patient's safety and to prevent over consumption of new and more expensive drugs. Justified off-label drug use requires a thorough assessment. Physicians, in cooperation with formulary committees, need tools to structure this assessment. The evaluation algorithm for off-label prescription we present here, to be used after identification of a planned off-label application, consists of four steps. Step 1 indicates the extent of the problem and the need for further investigation. Step 2 is the decisional process evaluating the necessity of off-label use in identified prescriptions and confirmation as to what extent it needs further investigation. In step 3, the scientific knowledge to support the proposed off-label use is gathered in a short or extensive evaluation trajectory. The short trajectory consists of assembling the information approved in other countries or in accepted guidelines and textbooks, whereas the extensive trajectory is necessary when the indication, route, or formulation is not approved nationally or internationally. Assessment needs to be based on a literature research on the clinical and pharmacological information of the product. Step 4 is the acceptance or rejection of the off-label use of the drug for the indication at hand. Those four steps need to be carefully documented. Treatment outcome will then be closely monitored, documented, and made available to professionals, thus allowing for regular update of recommendations. This algorithm can help formulary committees to develop a strategy for evaluating off-label prescriptions in well-defined conditions, and help healthcare providers to develop protocols and guidelines.