SCAGLIONE F, PINTUCCI JP, FRASCHINI F; Interscience Conference on Antimicrobial Agents and Chemotherapy (42nd : 2002 : San Diego, Calif.).

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2002 Sep 27-30; 42: abstract no. A-1414.

University of Milan, Milan, Italy.

BACKGROUND:, Homogenization of a fluid samples, centrifugation and subsequent antibiotic assay of the supernatant have been used to predict the activity of antibiotic concentrations.The objective of this study is to test the hypothesis that the concentrations of Cefaclor (CEF) or Amoxicillin/clavulanic acid (AMX/CA) in middle ear fluid (MEF) collected preserving the stability, clearing the cell contents and assayed using the HPLC are greater than those collected, processed and assayed using a traditional method. METHODS:,58 children with effusive otitis media were treated orally with CEF 20 mg/kg or AMX/CA 20 mg/kg (AMX/CA 7:1 ratio). Samples were obtained from 1 to 6 hours after dosing (one sample for each subjects). Contemporary serum sample were assayed. Each, blood-free, fluid sample over 300 microl was divided into two fractions. One fraction (C+) assayed traditionally. The second fraction (C-) was cleared from the cells. All fluids were assayed by HPLC. RESULTS:, CEF levels in MEF has been obtained in 21 subject over 40.The peak level is reached around 2 hours after dosing. The AUC of CEF in C- fluid (21.65 mg/L*h) resulted higher than in C+ (14.23 mg/L*h) as well as in serum. (18.18 mg/L*h). AMX and CA levels in MEF has been obtained in 13 subject over 19.The peak level is reached in 2 -3 hours post dosing. Concentrations of CA are often not measurable 6 hours after dosing. The AUC of AMX and CA in C- fluid (22.99 and 5.045 respectively) is also higher than in C+ (16.80 and 3.605 respectively) as well as in serum. (17.21 and 3.865 respectively).CONCLUSIONS:, The concentrations in free cell fluid appear higher than those in the total fluid (as assayed traditionally). The AUC of CEF as well as of AMX/CA in serum is similar to the AUC of The C- fluid while is higher than the C+ fluid. Apart from straightforward errors in the methods of processing the assay of drug levels in tissue, the concentrations in extracellular fluid (site of bacterial growth) of beta-lactams are grossly underestimated.

Publication Types:

• Meeting Abstracts

Keywords:

• Amoxicillin
• Amoxicillin-Potassium Clavulanate Combination
• Anti-Bacterial Agents
• Cefaclor
• Child
• Clavulanic Acid
• Ear, Middle
• Humans
• Otitis Media
• beta-Lactams

Other ID:

• GWAIDS0026989

UI: 102266613

From Meeting Abstracts