I am on my fourth day of Doxy. Like many of the other posts I also experienced side effects not listed on my prescrip. info. sheet. The first day or so I did feel as though I was in a fog and was also very tired feeling. One night I felt like I had something in my throat and also burning in my throat. I was prescribed Doxy for having pneumonia so the tirdness may very well have been from that. The best advice that I can give that helped to relieve my side effects was to drink A LOT! of water when taking this medicine (20 oz) not the 8 oz advised. And to keep drinking water throughout the day and night. My side effects have all but gone away and I am starting to feel so much better.. Although I have not been in the sun it cannot be expressed enough that you should avoid the sun while on this med. And if you are having side effects try not to panic that will just intensify what is going on. Remember the side effects are sometimes better to have then the actual illness you are being treated for. But please drink tons of water. Also side effects can be reported to the FDA at 1-800-FDA-1088. If enough people call then maybe they will add new side effects to this med.