In vitro activity of cefaclor against aerobic and anaerobic bacteria

Structure-Based Analysis of Cefaclor Pharmacokinetic Diversity According to Human Peptide Transporter-1 Genetic Polymorphism

Cefaclor is a substrate of human-peptide-transporter-1 (PEPT1), and the impact of inter-individual pharmacokinetic variation due to genetic polymorphisms of solute-carrier-family-15-member-1 (SLC15A1) has been a topic of great debate. The main objective of this study was to analyze and interpret cefaclor pharmacokinetic variations according to genetic polymorphisms in SLC15A1 exons 5 and 16. The previous cefaclor bioequivalence results were integrated with additional SLC15A1 exons 5 and 16 genotyping results. An analysis of the structure-based functional impact of SLC15A1 exons 5 and 16 genetic polymorphisms was recently performed using a PEPT1 molecular modeling approach. In cefaclor pharmacokinetic analysis results according to SLC15A1 exons 5 and 16 genetic polymorphisms, no significant differences were identified between genotype groups. Furthermore, in the population pharmacokinetic modeling, genetic polymorphisms in SLC15A1 exons 5 and 16 were not established as effective covariates. PEPT1 molecular modeling results also confirmed that SLC15A1 exons 5 and 16 genetic polymorphisms did not have a significant effect on substrate interaction with cefaclor and did not have a major effect in terms of structural stability. This was determined by comprehensively considering the insignificant change in energy values related to cefaclor docking due to point mutations in SLC15A1 exons 5 and 16, the structural change in conformations confirmed to be less than 0.05 Å, and the relative stabilization of molecular dynamic simulation energy values. As a result, molecular structure-based analysis recently suggested that SLC15A1 exons 5 and 16 genetic polymorphisms of PEPT1 were limited to being the main focus in interpreting the pharmacokinetic diversity of cefaclor.

Pharmacokinetic study of cefaclor in chronic maxillary sinusitis

The pharmacokinetics of the maxillary sinus fluid were studied in 42 patients (26 males and 16 females), suffering from chronic maxillary sinusitis, after oral administration of 0.5g or 1g cefaclor. A thin plastic catheter, for sinus secretion sampling, was inserted in the sinus cavity and remained in place throughout the study. Sinus fluid levels of cefaclor (0.5g), measured by agar and well-diffusion microbiological method, ranged between 0.17-0.19, 0.28-0.42, 0.18-0.22 and 0.12-0.16 microgram/ml at 2, 4, 6 and 8 hour intervals respectively. Levels ranging between 0.15-0.26, 0.37-0.90, 0.23-0.27 and 0.16-0.19 microgram/ml were found after the administration of 1g cefaclor at the same time intervals respectively. Higher levels were found in purulent nasal material than in cystic fluid aspirates.

Cefaclor pharmacokinetic parameters: serum concentrations determined by a new high-performance liquid chromatographic technique

Pharmacokinetic parameters of cefaclor were studied in eight patients after an oral dose of 250 mg. Serum samples were obtained before and on 19 occasions after oral administration. Cefaclor serum concentrations were determined by a new high-performance liquid chromatographic technique.

Concentration of cefaclor in human prostatic tissue

Concentration of cefaclor, a new oral cephalosporin, was measured in prostatic tissue of ten patients undergoing suprapubic prostatectomy. The average prostatic tissue concentrations were 0.51 +/- 0.22 microgram and 0.74 +/- 0.67 microgram per gram of tissue following the oral administration of 250-milligram and 500-milligram doses, respectively. The prostate/plasma ratios of cefaclor were approximately 0.7 indicating no evidence of accumulation of the drug in prostatic tissue. Levels of cefaclor achieved in human prostatic disease are equal to or less than the minimum inhibitory concentration of strains of known facultative bacterial pathogens associated with prostatitis.

Autobac I procedure to assess susceptibility to Cefaclor

Agar dilution and Autobac I tests were performed to compare the susceptibility of 1,000 bacterial isolates to cefaclor and cephalothin. The standard Autobac methodology will correctly predict resistance to cefaclor. The test methodology seems to influence in vitro results, since more strains of gram-negative bacteria were susceptible to cefaclor by the Autobac I method than by the agar dilution test.

Comparative in vitro activity of 1-oxa-beta-lactam (LY127935) and cefoperazone with other beta-lactam antibiotics against anaerobic bacteria

The in vitro activity of 1-oxa-beta-lactam (LY127935), cefoperazone (T-1551), cefuroxime, cefsulodin, cefaclor, cefotaxime, and cefoxitin on 85 anaerobic clinical isolates (30 Bacteroides, 30 Clostridium, 25 Peptococcaceae) was simultaneously determined by the agar dilution test in two different media, Brucella Agar (Difco Laboratories) and Wilkins-Chalgren agar. In Wilkins-Chalgren agar, 90% of Bacteroides were inhibited by (micrograms per milliliter): LY127935, 0.5; T-1551, 64; cefoxitin or cefuroxime, 8; cefsulodin or cefotaxime, 32; and cefaclor, 128. All Clostridia were inhibited in Wilkins-Chalgren by (micrograms per milliliter): LY127935, 4; T-1551, 2; cefoxitin, 6; cefuroxime, 0.12; cefsulodin, 0.5; cefaclor, 1; and cefotaxime, 8. All Peptococccaceae were inhibited by T-1551, cefsulodin or cefotaxime at 4 microgram/ml and by cefoxitin or cefuroxime at 1 to 2 microgram/ml. With cefaclor at 8 microgram/ml, 92% of strains were inhibited, and LY127935 at 16 microgram/ml only inhibited 64% of strains. LY127935 was the most active of the antibiotics tested against Bacteroides, showing good activity against Clostridia and poor activity on Peptococcaceae, whereas T-1551 was more active against Peptococccaceae and had similar activity against Clostridia and poor activity on Bacteroides. There are no significant differences between minimal inhibitory concentrations obtained in Brucella Agar and those obtained in Wilkins-Chalgren.