Doxycycline Hyclate Side Effects: i have been on doxcycline for a couple of days for a sinus infect http://www.medications.com/effect/view/17997 i have been on doxcycline for a couple of days for a sinus infection and have noticed chest pain from heart burn from this medication i only have a couple of days left i am not sure if it is worth continuing, it is quite a bad burning sensation. The Doxycyline finally stopped working, I am coughing up thick gr Wed, 30 Jan 2008 11:00:14 -0500 http://www.medications.com/effect/view/17997?item=4490 The Doxycyline finally stopped working, I am coughing up thick green muscous (sorry to be so gross), and have an appointment tomorrow aftrernoon with my primary doctor, for Z-Pack, which is usually efective for me. When I take Doxycyline, I get really hot http://www.medications.com/effect/view/17997?item=4490