if you need to take more pain reliever in the morning or whenever it is that you take the 325mg aspirin, i would use additional aspirin rather than mix.

offhand, not sure about tylenol coadministration - i've 'heard' mixed things but never seen anything concrete to indicate problems so it may well be ok.

but definitely avoid taking aspirin and other NSAIDs (like ibuprofen), at the same time. if you want to take ibuprofen or similar NSAID, make sure at least 4 hours have gone by since the aspirin. generally, the aspirin-like NSAIDs should not be intermixed.

~ waves ~