Enzalutamide

Posterior reversible encephalopathy syndrome (PRES) has been reported in patients receiving enzalutamide. PRES is a neurological disorder which may present with rapidly evolving symptoms (headache, seizure, lethargy, confusion, blindness, and other visual/neurologic disturbances) with or without associated hypertension. PRES diagnosis may be confirmed with magnetic resonance imagining (MRI). Discontinue enzalutamide in patients who develop PRES.

Seizures were observed in clinical trials; patients with predisposing risk factors for seizures were generally excluded from these studies. The onset of seizure ranged from ~1 to 20 months after treatment initiation. Enzalutamide was permanently discontinued in patients experiencing seizures; seizures resolved upon therapy cessation. In a study designed to assess seizure risk in patients with predisposing factors, 2.2% of patients who received enzalutamide experienced a seizure; after the first seizure resolved, a few of those patients experienced a second seizure with continued enzalutamide treatment. It is not known if antiepileptic medications can prevent enzalutamide-related seizures. Patients in the study had one or more predisposing factors, including the use of concomitant medications that may lower the seizure threshold, history of traumatic brain or head injury, history of cerebrovascular accident/transient ischemic attack, and Alzheimer disease, meningioma, or leptomeningeal disease from prostate cancer, unexplained loss of consciousness within the last 12 months, prior seizure history, presence of a space occupying brain lesion, history of arteriovenous malformation, or history of brain infection; some patients had more than one risk factor. Advise patients of the risk of seizures during enzalutamide treatment and of the risk of engaging in activities where sudden loss of consciousness could cause serious harm to themselves or others. Discontinue enzalutamide perma

May cause hypospermatogenesis; may impair male fertility. Disease-related concerns:

Androgen-deprivation therapy may increase the risk for cardiovascular disease (Levine 2010). An increase in systolic and diastolic blood pressures has been observed (Scher 2012); may worsen preexisting hypertension. Concurrent drug therapy issues:

Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information. Dosage forms specific issues:

May contain sorbitol.