Is cephalexin or amoxicillin stronger? When dosed appropriately, both antibiotics are effective against their covered organisms. The organism coverage of cephalexin makes it effective in some conditions that amoxicillin is not, including mastitis and bone and joint infections.
Tetracyclines (e.g. doxycycline), quinolones (e.g. ciprofloxacin), macrolides (e.g. clarithromycin), aminoglycosides (e.g. gentamicin) and glycopeptides (e.g. vancomycin) are all unrelated to penicillins and are safe to use in the penicillin allergic patient.