Cellulitis not responding to keflex. . . . . . . I am taking Keflex and Vicodin and I hope to be feeling better soon. . Then it stopped responding, and turned into cellulitis, and antibiotics and anti . . . . Bactrim) and Cephalexin (Keflex) Linezolid . . Cellulitis treatment may involve a prescription oral . . MRSA's do not repsond to . MRSA infections respond to clindamycin, bactrim or vancomycin. abscess tooth is cephalexin a sulpha based drug infection not responding to keflex . . The drug... more