Clinics would not help my infected index finger from an insect bite. they said go to emerg. i found cefprozil from a relative. no insurance, any advi?

Don't do it.: Taking a relative's medication is never a good idea for many reasons - you may be allergic, & nobody is monitoring you, for starters. And how do you know it's infected? Most bites do well with a mild cortisone cream and antihistamines for the itching, but if pain or significant tenderness develops, you'll need to see a doctor (sorry) and get the right antibiotic, not your relative's leftovers.