Women with a mild penicillin allergy can be given Cefazolin plus gentamicin Women with a severe penicillin allergy can be given one of the following: Clindamycin (or metronidazole) plus gentamicin Vancomycin plus gentamicin Vancomycin should be used in women who are colonized with group B streptococci (GBS) if GBS is resistant to clindamycin or erythromycin unless clindamycin - inducible resistance testing is negative.