title: Subtherapeutic dicloxacillin levels in a neonate: possible mechanisms.
abstract: A neonate treated initially with oxacillin intravenously for two weeks and who was receiving phenobarbital for a seizure disorder subsequently failed to achieve therapeutic levels of orally administered dicloxacillin, even when the dosage was as high as 175 mg/kg/day. Intestinal absorption was documented by high serum peak levels. The low trough levels correlated with a high urinary excretion rate. The possibillity that renal tubular transport of dichloxacillin was stimulated by administration of penicillin derivatives (and/or phenobarbital) is suggested, and the need for careful monitoring of serum levels of antibiotics in neonates is emphasized.
mesh_terms: D000284:Administration, Oral; D001170:Arthritis, Infectious / Q000188:drug therapy*; D004009:Dicloxacillin / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D006621:Hip Joint / Q000382:microbiology; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000188:drug therapy*; D007263:Infusions, Parenteral; D007408:Intestinal Absorption; D010068:Oxacillin / Q000008:administration & dosage / Q000627:therapeutic use; D010634:Phenobarbital / Q000627:therapeutic use; D013203:Staphylococcal Infections / Q000188:drug therapy*
chemical_list: D004009:Dicloxacillin; D010068:Oxacillin; D010634:Phenobarbital