Has anyone ever taken Doryx (an antibiotic) for acne? My son has been on it for 2 weeks and I swear his skin looks 100 times worse. I wasn't happy about trying it anyway, but he begged me (he's 13 and his skin has gotten bad over the last year). We've tried 7 other things from the dermatologist (that cost me a small fortune) and nothing worked. Any suggestions? THANKS!