They can be taken together to increase the effectiveness of both drugs. Celebrex and Tylenol are in different classes of pain medication. If you take them both together, they work stronger than either one alone. It's a case of 1 + 1 = 3 in terms of the effectiveness of the medication. One Celebrex and one Tylenol are more powerful in relieving pain than two Celebrex alone or two Tylenol alone. The medical term for this is "synergistic."