Determination of the renal concentration capacity following intravenous administration of dDAVP in healthy humans.

The synthetic AVP analogue 1-desamino-8-d-arginine-vasopressin (dDAVP) is used for treatment of polyuric disorders. Lack of commercially available assays limits the usefulness of dDAVP as a diagnostic tool in the assessment of renal concentrating capacity. We aimed to develop a specific radioimmunoassay (RIA) for determination of plasma dDAVP (pdDAVP) in order to investigate the relationship between pdDAVP levels and urine osmolality (Uosm). Further, we aimed to determine the onset, duration, and maximum concentrating capacity following intravenous (i.v.) bolus dDAVP injection. The dDAVP assay was based on a well-established RIA for measurements of AVP. Fourteen healthy subjects (aged 15-18 years) participated. Blood and urine samples were collected prior to and after i.v. bolus of 0.03 µg/kg dDAVP. Diuresis and Uosm was measured for nine hours following dDAVP administration. PdDAVP and Uosm were analyzed.We established a specific RIA for the measurement of pdDAVP. All subjects reached maximal pdDAVP concentration (Cmax) 30 minutes following infusion, and a rise in Uosm after 60 minutes. Maximal Uosm varied between subjects, with no direct correlation to the achieved pdDAVP levels. We found no significant intra-individual variation between two dDAVP infusions and the effect was reproducible in terms of Cmax and maximal Uosm. We characterized the relationship between pdDAVP and Uosm after dDAVP bolus injection in healthy adolescents using our dDAVP assay. Maximal Uosm achieved correlated with the baseline Uosm levels and seemed unrelated to achieved pdDAVP levels. The urine concentrating response was maintained at least eight hours.

Desmopressin as an adjuvant to opioids or NSAIDs in treatment of renal colic: a nationwide register-based study.

AIMS: Desmopressin has been reported to be effective as an adjuvant to opioids or NSAIDs in management of pain in renal colic; however real-life data are lacking on the utilisation of desmopressin in this patient segment. METHODS: The Danish National Prescription Registry data-linked with Danish National Patient Registry during a 3-year period from 2009 to 2011 was used to study prescriptions for desmopressin in renal colic. RESULTS: We identified 888 desmopressin prescriptions for renal colic, dispensed to 95 patients. The mean treatment period was 159 days, with a large variation up to a maximum of 924 days. Approximately two thirds of patients received dosing instructions to administer the drug 4 times daily to provide 24-h antidiuretic coverage. Among concomitant opioids and NSAIDs, tramadol and ibuprofen were prescribed most frequently. Antidepressants and diuretics were also widely used. A clear sex difference was seen, with female renal colic patients having three times more prescriptions overall than males, and in particular receiving more antidepressants and psychotropic drugs. A total of 4 (4.2%) of the patients experienced hospital admissions because of hyponatraemia or polydipsia during the 3-year period. We confirmed a previous case report that nephrolithiasis could be at least an occasional complication of successful therapy of Central Diabetes Insipidus (CDI) with desmopressin, identifying 12 CDI patients in total, or 2.4% of all Danish CDI patients in that period, who were also treated for renal colic. CONCLUSION: In summary, these real-life prescription data provide exact epidemiological measures on desmopressin utilisation in renal colic.