Peta McMuster is a 20-year-old woman with migraine who has sought treatment. She has been taking sumatriptan as a nasal spray to improve her condition. She recently became quite depressed and required treatment. Her doctor started her on therapy with the selective serotonin reuptake inhibitor fluoxetine. She soon experienced sweating, hyperreflexia, muscle twitching and abnormal foot movements. What complication of this antidepressant therapy is she experiencing? How has this come about? (Hint: you might want to refer to Chapter 30 to find out more about sumatriptan’s mechanism of action.) What is the treatment?