Can you take clindamycin po 300mg q6hrs for 30 days for cellulitis?

This would be unusual treatment. It likely would work, but it usually isn't necessary to treat cellulitis for more than 10-14 days, and clindamycin carries higher risk of potentially serious side effects than more usual antibiotics, such as cephalexin (Keflex) or sulfa-trimethoprim (Bactrim). But depending on the speciific cause, clindamycin may be the best choice. Discuss with the doctor.