Changing the Timing of Enzalutamide Intake from Morning to before Sleep at Night Overcame Enzalutamide-Induced Dysgeusia

Dysgeusia is an adverse effect caused by enzalutamide said to affect 1–5% of patients. The reported management strategies include a temporary drug holiday, the prescription of herbal medicine, and changing the timing of enzalutamide intake from morning to before sleep at night. Case 1: A 72-year-old man developed castration-resistant prostate cancer (CRPC) and was administered enzalutamide. After six weeks of enzalutamide installation, he showed taste alternation, and consequently his dysgeusia increased to grade 2; we therefore changed the medicine intake time from morning to night just before sleep without dose reduction. Four weeks after changing the timing, his dysgeusia had improved. Case 2: A 63-year-old man had developed bone metastatic CRPC, so the combination of Ra-223 and enzalutamide (160 mg/body) was introduced. His serum PSA level had gradually decreased, but dysgeusia appeared, so we changed the timing of enzalutamide intake from morning to night just before sleep without dose reduction. One month after changing the timing, his dysgeusia had improved. We herein report two cases of enzalutamide-induced dysgeusia successfully treated by changing the timing of drug intake from morning intake to just before sleep.