My 12 yr old daughter has been taking Doxy for 1 1/2 months to cl...

My 12 yr old daughter has been taking Doxy for 1 1/2 months to clear her mild acne. I thought it was the wonder drug because after 3 weeks her skin looked so much better, BUT then her skin started declining again, I can see the acne coming back. She's been complaining of pretty bad stomach pain, nausea and dizziness. I have also noticed major mood swings. She is usually a very happy girl, but now she gets moody and anxious more often than not. She is highly allergic to Benzoyl Peroxide, so she can't use Proactive or any other product with the same ingredients. After reading this site I will stop giving her Doxy immediately! Has anybody found anything that works for acne?