My research says that he should not be mixing the amitriptyline and codeine. The Tylenol 3's should be stopped 4 hours before his amitriptyline dose is taken and not taken again until 8 to 12 hours after the last amitriptyline dose.

If his doctor has OK'ed him to take aspirin, he can take a maximum dose of aspirin and Tylenol together. They are about as good at pain relief as the Tylenol 3's. I was taught this trick by my doctor. I use it for my worst head aches.

He needs to take a break from the Tylenol from time to time, at least 12 hours or more. Tylenol is rough on the liver.