Doxycycline Hyclate Side Effects: I was put on 100mg 2x daily for a sinus infection and now I still http://www.medications.com/effect/view/37008 I was put on 100mg 2x daily for a sinus infection and now I still have the infection plus other problems. I am a heavy eater and have not had a appetite for 3 days. I have some general stress and anxiety but this stuff has made it terrible. I have racing th Im right up there with you on the loss of appetite Jerry, althoug Tue, 02 Dec 2008 18:16:33 -0500 http://www.medications.com/effect/view/37008?item=14962 Im right up there with you on the loss of appetite Jerry, although knock on wood, that seems to be the only side effect.... http://www.medications.com/effect/view/37008?item=14962