Low-Dose Desmopressin Nasal Spray and FDA Approval—Reply

In Reply Drs Fein and Herschkowitz indicate that the pharmacokinetics of desmopressin nasal spray (Noctiva) mitigate the risk of hyponatremia while preserving efficacy. However, the drug was approved with a boxed warning, “Noctiva can cause hyponatremia, which may be life-threatening if severe.” This prominent FDA-required statement supports the contention that hyponatremia was still seen by the reviewers as an important risk from use of this medication. The authors also state that all 5 deaths in the desmopressin group were unrelated to the product, but this differs from the phrasing in the FDA report: “All deaths occurred among patients in the desmopressin group and none occurred in the placebo group, although 3 deaths were deemed by the FDA to be unrelated to the medication.”