http://www.prescriptiondrug-info.com/threads/can-keflex-be-taken-for-sinus-infections-D75087_s2.htm Recent Posts About can keflex be taken for sinus infections? at The People's Medicine Community. I have allergies, I take allergy shots. I have a prescription of Keflex 500mg. I was wondering if I can t;ake the Keflex for the sinus infection. en-us Copyright 2009 Prescription Drug Info All Rights Reserved. 11/21/2009 10:43:15 PM 20 http://www.PrescriptionDrug-Info.com/threads/can-keflex-be-taken-for-sinus-infections-D75087_s2.htm#160868 It is an antibiotic, so it can be used for many types of infections, however, how do you know you have a sinus infection? Also, if the prescription is old, it will not be as effective, you need to see your doctor. Thu, 11 Sep 2008 13:20:19 -0800