"i&#039;m 14 years old, and my dermatologist prescribed doryx for me for 2 months and all it did was create worse acne. i have no idea why it didn&#039;t work, but i was put on sulfamethoxazole about a week ago, and i already see a difference. my dermatologist said this drug is almost the same as doryx, but has a different molecule in it. if you are going to try doryx, i would definitely take it with food. with doryx i threw up 4 times because i didn&#039;t take it with enough food."