Abstract
Effects of dexamethasone, betamethasone and hydrocortisone on concentrations of cephalothin (CET) and cephalozin (CEZ) in both blood and tissue were examined using rats and rabbits, and the following results were obtained: When dexamethasone (0.25 mg/kg) was administered to rabbits subcutaneously in combination with CET and CEZ, the plasma level of CET decreased remarkably in the initiat time after administration of this antibiotic, while the plasma level of CEZ increased significantly. Plasma levels of CET and CEZ were decreased to some extent by intravenous injection of dexamethasone. When betamethasone (0.25 mg/kg, 1.25 mg/kg) and hydrocortisone (10 mg/kg, 50 mg/kg) were administered by drip infusion in combination with CET and CEZ, concentrations of these increased remarkably. A large dose of dexamethasone (2.5 mg kg drip infusion) decreased plasma levels of these antibiotics, while a small dose of this drug (0.25 mg/kg, 1.25 mg/kg) increased these plasma levels. When CET (200 mg/kg) and CEZ (200 mg/kg) were administered intramuscularly to rats 1 hr. after an oral administration of probenecid (50 mg/kg), the plasma level of CET and CEZ increased. In contrast, the plasma level of these cephalospoline preparations was decreased by intramuscular administration of dexamethasone (5 mg/kg) . Both CET and CEZ were distributed in kidney, spleen, lung and small intestine after intramuscular administration of these cephalospolin preparations to rats. Cef azoline also was distributed to the liver and the concentration of this drug in this tissue was increased significantly by intramuscular administration of dexamethasone and oral administration of probenecid. When dexamethasone (0.22-0.26 mg/kg) was administered in combination with CET (24-207 mg/kg) or CEZ (38.5-83.0 mg/kg) to children with acute infections, plasma levels of these antibiotics increased. In 8 children with acute infections, 4 cases responded well.
