LAUSR

Introduction: Pazopanib is an oral protein kinase inhibitor (PKI) that targets vascular endothelial growth factor (VEGF) receptors, fibroblastic growth factor receptors, platelet-derived growth factor receptors, and stem cell factor that inhibits VEGF-induced cellular proliferation. Pazopanib is approved for use in advanced renal cell carcinoma and subtypes of advanced soft-tissue sarcoma (Deguchi et al., 2018). Major adverse drug reactions of pazopanib include hypertension, high-grade hyponatremia and posterior reversible encephalopathy syndrome (PRES) (Berardi et al., 2016; Deguchi et al., 2018). In clinical trials, few investigations have been conducted to determine the aetiology of PKI-associated hyponatremia, the mechanism remains therefore unknown. Only rare cases of PKI-induced syndrome of inappropriate secretion of antidiuretic hormone (SIADH) (Largeau et al., 2019), and none with pazopanib, have been reported. PRES is a clinical and radiological entity where a bilateral white matter oedema, occurring predominantly in the posterior occipital and parietal lobes, is associated with several neurologic symptoms. Interestingly, a recent review suggests that SIADH could be a symptom of PRES (Largeau et al., 2019). To our knowledge, this is the first case published where pazopanib-induced PRES occurs contemporaneously with possible SIADH.