<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi, my grandfather is on regular Tylenol2 every midnight. He also has a PRN Tylenol2 to be given every 4 hrs. Sometimes, after an hour of taking his regular Tylenol2 he complains of leg pain again. Is it safe to give him his PRN that soon even if he just had one?  <response>: Hi, Regular Tylenol2 contains acetaminophen 325 mg or 500 mg and is commonly used to relieve pain and fever. Whereas PNR Tylenol2 is a combination of acetaminophen-300 mg and an opioid pain reliever codeine-15 mg which is used to relieve mild to moderate pain. Yes, PNR Tylenol2 may be given safely as needed basis to relieve the pain but remember the total dose of acetaminophen should not exceed 3.25 g per day. Hope I have answered your question. Let me know if I can assist you further. 