This is a good question and the answer is that this is almost certainly effective therapy for chlamydial infection, HOWEVER, treatment of chlamydia with azithromycin has not been formally studied using this dosing schedule. Soon after
azithromycin was released, it was shown that taking a Z-
pack, consisting of 500 mg on day one, followed by several days of 250 mg per day was slightly less effective than a single 1.0 gram dose.