If you are on Prozac, overdose is a real possibility. So, be very careful to take the medication as prescribe by your doctor. He/she may even have to adjust the dose, if you are having increased thoughts of suicide, and you are tempted to act upon those ideas. In addition, if you are taking an MAOI with Prozac, overdose of serotonin is definitely a real possibility. In fact, it can be a deadly side effect. If you are experiencing adverse side effects from the medication, contact you doctor immediately. You may even have to go to the emergency room and spend the night in the hospital, until your serotonin levels return to a safe level.