Gastroenteritis
"500mg (1 dose each day). 

When I took Doxycycline the first time, there was irritation along the back of my throat, followed by a slight headache.

The next day, I took my next dose and immediately my head felt tight and full of pressure. It took 9 hours to subside and almost double that to get rid of it completely. I looked up the side-effects on this site and apparently intra-cranial pressure is rare but can happen. This antibiotic may work wonders for some people but for me it was not a good experience.

I am now on a different antibiotic for my condition which is making me feel tired and hungry all the time. It&#039;s still better than crippling headaches.

Avoid Doxycycline if you feel ill with it. It&#039;s not worth the pain."