My DS went to a dermatologist in Boston, he waited 3 months for the appointment (he's a young doctor who graduated from Harvard) by then his face had very bad acne. He perscribed cefadroxyil 250 mg 2 tsp. twice a day. He gave him liquid because it works faster and it did, within 3 weeks his skin was CLEAR!
He also gave him Benzaclin to rub on in the morning and Differin cream to rub on at night. He washes his face with plain water, it's very sensative.
Has him wash pillowcases in Ivory Soap Liquid so theres nothing else interfering.
The combination of these perscriptions has really made a big difference, he has another appointment in March because he's been off the cefadroxil for a month now and we can see some blackheads starting to form in the pores again which means they are getting blocked somehow. So it will be interesting to see what he does next.
Before this he tried everything over the counter along with Proactive etc. that you can think of and a lot of $$.
Good Luck, hope you find something that works for you.