I avoid taking anything if I can help it. Like Jeannie, my thyroid meds don't like most oral decongestants, cough syrups, et al, and my body doesn't respond well to most drugs (I can do without the palpatations & anxiety :(
Fluids, and more fluids and lots of rest, too. As far as my sugar levels go when I'm sick...I allow anything up to 5 points higher than what my "normal" is, to be acceptable.
I stay away from mucus-producing foods like dairy, too. A glass of milk will choke ya if you can't breathe through your nose