Can Erythromycin treat strep throat

Refer to this link

http://cid-d021de92b4bdb09f.spaces.live.com/blog/cns!D021DE92B4BDB09F!258.entry

which posted by Thai pharmacist. He state that "roxythomycin" is the medicine in the same group of erythomycin and they were use in organic of upper respiratory system.