Hi - My son(14 years) was diagnosed with a strep throat on Tuesday and was put on the Z-pak (he is allergic to penicillin and amoxicillin). He has had the 2pills(500mg) on Tuesday and 1 pill(250mg) yesterday. The doctor's office called this morning and told me that the dosage was wrong and that he has to do 2 pills (500mg) for 4 more days - he would have had 2750 mg in all by Sunday(in 6 days) - I read that the dosage for strep is 1500 mg - this is almost double - is this an overdose? Thanks.