question: Is Rifampin useful in treating bacterial cellulitis? My mother recently got a prescription for Rifampin and Doxyclline, both BID x 10 days. I am a pharmacist, but am not familiar with Rifampin and cellulitis. She has already been on Clindamycin and Keflex, both of which helped. The redness has almost subsided, but she still has swelling between the knee and ankle. Thanks for your response.