Sunitinib-induced Acute Psychosis: Case Report

Sunitinib is an oral multi-targeted tyrosine kinase inhibitor licensed for the treatment of renal cell carcinoma both in the first line and post immunotherapy setting. The toxicity profile of sunitinib is well established and guidelines to manage the most frequent side effects are available. However, a number of uncommon toxicities have also been described. Their occurrence is often challenging for the clinician because rare side effects may not be recognised and because treatment protocols have not been formulated. Here we present a case of a patient with metastatic renal cancer and history of bipolar disorder who developed an acute psychotic episode whilst undergoing treatment with sunitinib. The psychotic symptoms did not respond to antipsychotic medications but resolved spontaneously 7 days after the discontinuation of the drug. Investigations excluded infection or brain metastases as potential causes for the psychotic episode. Psychiatric side effects are rare with sunitinib and only three case reports have been published so far. The underlying pathophysiological mechanisms of this toxicity are poorly understood. Our patient had a previous history of bipolar disorder whereas in the other 3 published cases had a background of arteriosclerotic leukoencephalopathy due to small vessel disease. It is possible that such pre-existing conditions played a role in the onset of the psychiatric symptom. Clinicians should be aware of co-morbidities which could predispose to severe toxicities when initiating cancer therapy, particularly for patients treated with palliative intent.