the nurse that taught me to do my avonex told me to take 2 tylenol and 2 benedryl 2 hours before injection and to repeat every 4 hours with tylenol and every 6 with benedryl . Although it made me sleepy it worked wonders. when i would fall asleep and forget to take my meds I would wake up with the nasty flu like stuff. Unfortunately after 2 months on the Av I started having weird reactions and breaking out in hives despite the bene so I started TY last month.