Is it okay to take a morphine sulfate er 30mg after taking tylenol (acetaminophen) 3?

Combining narcotics: Caution is indicated. Combining narcotics can cause dangerous sedation. With that said, it is common to use ms er for sustained pain control, and then to add a shorter-acting pain medication, like tylenol (acetaminophen) #3, for acute flare ups (breakthrough pain). It is usually safe used in this way, but a careful test dose with a smaller amount (say 1/2 tab) is a good idea.