Meloxicam-desmopressin drug-drug interaction producing hyponatremia

People with schizophrenia and medical comorbidities are often on multiple medications to manage their symptoms. Herein we present a case of drug-drug interaction (meloxicam and desmopressin), in a patient also on clozapine, that ultimately resulted in hyponatremia and seizure.

The patient provided consent to have his case published. We searched PubMed and after reviewing 321 articles, 11 were chosen for relevance.

Meloxicam enhanced the adverse effect (hyponatremia) of desmopressin and was the likely culprit.

In a patient with higher ADH levels, as in our patient taking desmopressin, the addition of an NSAID could further increase water retention and worsen hyponatremia; indeed, meloxicam was the only new medication added to the patient's regimen, and a drug interaction calculator supports the desmopressin-meloxicam drug-drug interaction as the culprit. We urge clinicians to avoid the use of desmopressin in patients with schizophrenia as this can lead to water intoxication. As meloxicam may worsen desmopressin-induced hyponatremia and could result in seizure, one should avoid using NSAIDs in patients with schizophrenia whom are also prescribed vasopressin/desmopressin. Serum sodium levels should be closely monitored in patients with schizophrenia whose regimen includes desmopressin.