Second choice would be either a second- or third-generation cephalosporin or azithromycin, depending upon the degree of macrolide resistance in your community. Here in Rochester, where macrolide resistance is about 8%, we normally go with cefprozil, cefdinir, or cefpodoxime. All three are generic, although they're still not cheap— there's currently only one distributor. Cefprozil is the least expensive of the three, and there also is evidence that it eradicates the strep carrier state as well as the active infection (Clin.Ther. 2001;23:1889–900).
The Infectious Diseases Society of America is planning to issue new guidelines for the treatment of streptococcal pharyngitis sometime in 2008. Dr. Kaplan is the chairman of the writing committee, and Dr. Casey is a member. The American Academy of Pediatrics' 2006 Red Book still recommends amoxicillin as first-line therapy, but I'm guessing that will not be the case in the next edition, due out in 2009.
I have no financial conflicts that are relevant to this article.