My Husband Has Prostititis (for Months Now) He Had A

My husband has prostititis (for months now) he had a urine culture done and it showed e coli he is allergic to many drugs the dr gave him Keflex but the lab work did not test Keflex but other drugs in the same family and the e coli is susceptible to cefoxitin is Keflex still ok or should he go with what was tested