DDAVP and sodium

 Q:  Desmopressin (DDAVP) tends to cause? (select one)

A) hyponatremia

B) hypernatremia

Answer: A

Desmopressin is actually a 1-deamino-8-D-arginine vasopressin, popularly known as DDAVP. As the name implies it is an analog of antidiuretic hormone and tends to decrease urine output. Consequently, it also causes hyponatremia besides some vasopressor activity. DDAVP is frequently given in ICU to bleeding patients. It improves the bleeding time by increasing the release of large factor VIII:von Willebrand factor multimers from endothelial cells. It is also postulated to increase platelet membrane glycoprotein expression. 

It should be noted that it quickly develops tachyphylaxis (usually after the second dose). The dose is 0.3 mcg/kg. It should be given slowly in an IV piggy bag for over half an hour period.

#hematology

#pharmacology

References:

1. Vande Walle J, Stockner M, Raes A, Nørgaard JP. Desmopressin 30 years in clinical use: a safety review. Curr Drug Saf. 2007 Sep;2(3):232-8. doi: 10.2174/157488607781668891. PMID: 18690973. 

2. Fralick M, Schneeweiss S, Wallis CJD, Jung EH, Kesselheim AS. Desmopressin and the risk of hyponatremia: A population-based cohort study. PLoS Med. 2019 Oct 21;16(10):e1002930. doi: 10.1371/journal.pmed.1002930. PMID: 31634354; PMCID: PMC6802819. 

3. Zeigler ZR, Megaludis A, Fraley DS. Desmopressin (d-DAVP) effects on platelet rheology and von Willebrand factor activities in uremia. Am J Hematol 1992; 39:90. 

4. Gordz S, Mrowietz C, Pindur G, et al. Effect of desmopressin (DDAVP) on platelet membrane glycoprotein expression in patients with von Willebrand's disease. Clin Hemorheol Microcirc 2005; 32:83.