Suggest Treatment For Staph Infection Below Knees

I have what my doctor describes as a Staph infection below my knee. Initially he tried Keflex but after almost a week it was getting worse. He change my medication to Flucloxacillin a couple of days ago. It is still quite red and sore and I would like to know, if the medication is appropriate how long before I will see any improvement? There was no mention on the packet of when to take them, so I just take them four times a day about six hours apart. thank you Robert