Gentamicin-cephalothin drug reaction

A case report describing the occurrence of nephrotoxicity in a 26-year-old black male with sickle cell anemia after concurrent i.v. administration of gentamicin sulfate and cephalothin sodium is presented. Cephalothin 1 g.i.v. every six hours was given for three days for a Klebsiella infection demonstrated by urine and blood culture to be cephalosporin sensitive. Cephalothin was then discontinued and gentamicin, after an i.v. loading dose of 2.6 mg/kg, was given for 14 days in a dosage of 1.3 mg/kg every eight hours. After cultures of pus aspirated from the right thigh demonstrated Klebsiella, 2 g of cephalothin was administered i.v. every six hours and gentamicin sulfate was discontinued. Gentamicin therapy was reinstituted two days later, at a dosage of 5 mg/kg/day. The gentamicin-cephalothin therapy was continued for nine days. The gentamicin dosage interval was increased from every eight to every 16 hours when serum creatinine and gentamicin levels became elevated. Gentamicin was discontinued entirely two days later because serum gentamicin levels were not decreasing. Previous case reports and studies of nephrotoxicity associated with concurrent gentamicin-cephalothin therapy are reviewed. Pharmacists should be alert to the possible increased incidence of nephrotoxicity occurring with concurrent genticin-cephalothin therapy.