I was diagnosed with strep yesterday & taken 3 doses of the z pack of antibiotic. fever still keeps coming back every 6-7 hours since sunday night. ?

Strep Throat: Pharyngitis is not adequately treated with a simple "Z-Pak". Assuming you are allergic to Penicillin - and can not take the usual preparations of Penicillin or Amoxicillin, preferably Augmentin, (amoxicillin and clavulanate) would normally recommend a "double- dose Z-pak" ie- 500 mg daily for 5 days, Check back soon with your regular provider for reassessment.

Timing: It can take up to 48 hours for an oral antibiotic to begin to affect your infection. I would give this a bit more time. But if you still are not improved in another 24 hours contact your MD. Zpacks are not the first medication recommended as sometimes the germ is smarter than this family of antibiotics. http://www.medscape.com/viewarticle/820736

What now?: To treat a sore throat: use an antibiotic to kill the organism; two, use something for pain. I don't know your wt but dose for ibuprofen is 10 mg/kg/dose every 8 hr. You may also be taking an incorrect dose of azithromycin.