Abstract
Liver transplant patients are frail subjects due to lifelong therapy with immunosuppressants. In these patients, comorbidity and polytherapy increase the risk of adverse drug reactions. In this study, we report the development of hyponatremia, probably related to pantoprazole in a liver transplant patient. Sertraline dismission and treatment with sodium chloride did not improve clinical symptoms and laboratory levels. Pantoprazole dismission induced an improvement in clinical symptoms and the normalization of sodium levels. A five-month follow-up revealed the absence of clinical symptoms and normal serum sodium levels.