Tylenol (acetaminophen) is safe, but do not take ibuprofen (Advil, Motrin) or naproxen (Aleve). For cold medications you must read the label because you should not use something with dextromethorphan (cough suppressant). Also, some already contain acetaminophen so you don't want to take double doses.
My doc has told me that Tylenol is ok as long as the dosage on the box is followed correctly.