Don't take zeposia if you've had a heart attack, chest pain, stroke or mini-stroke, heart failure in the last 6 months, irregular or abnormal heartbeat not corrected by a pacemaker, if you have untreated severe breathing problems during your sleep, or if you take medicines called maois. zeposia may cause serious side effects including infections that can be life-threatening and cause death, slow heart rate, liver or breathing problems, increased blood pressure, macular edema, and swelling and narrowing of the brain's blood vessels. though unlikely, a risk of pml--a rare, serious, potentially f...