Here's dosage information for Doxy:
Increasingly, clinicians recommend that certain drugs used for Lyme disease be given at higher daily doses: for example, 3,000–6,000 mg of amoxicillin, 300–400 mg doxycycline, and 500–600 mg of azithromycin. Some clinicians prescribe antibiotics using blood levels to guide higher doses. Close monitoring of complete blood counts and chemistries are also required with this approach.http://www.ilads.org/lyme_disease/treatment_guidelines_clearing_ilads.html
Bucci, the reason you are on a lower dose is probably because of you elevated liver enzymes. My LLMD did the same thing with me.