In vitro elution of tobramycin and vancomycin polymethylmethacrylate beads and spacers from Simplex and Palacos.

In vitro studies of antibiotic elution from polymethylmethacrylate cement comparing Simplex (Howmedica, Rutherford, NJ) with Palacos brands (Richards, Memphis, TN) have shown variable results. This study compares the elution of tobramycin and vancomycin from Simplex and Palacos beads and spacers. Six-millimeter beads and spacers were incubated in phosphate-buffered saline, and the solution was sampled and changed daily until the concentration of antibiotic fell below the minimum inhibitory concentration (MIC) for Staphylococcus aureus. In all groups, the Palacos PMMA beads and spacers showed elution at higher levels and remained above the MIC longer than did the Simplex PMMA beads. Tobramycin had superior elution to vancomycin in all groups. This in vitro study shows that Palacos PMMA has superior elution properties to Simplex PMMA in tobramycin and vancomycin beads and spacers.

Relation of surface area to in vitro elution characteristics of vancomycin-impregnated polymethylmethacrylate spacers.

To study the relationship between surface area and antibiotic elution from antibiotic-impregnated polymethylmethacrylate (PMMA) spacers, a standard block spacer made of vancomycin (4 g) and 40 g of PMMA was compared with two unique spacer designs, the "donut" and "fenestrated." The spacers were incubated in phosphate-buffered saline, which was changed daily, and a microbiologic assay was used to measure the antibiotic activity of the eluates. The donut and fenestrated spacers had 12% and 40% more surface area than the standard spacer, respectively. There was no significant difference, however, in daily elution levels of antibiotic between the donut spacer and the standard spacer. The fenestrated spacer displayed significantly better elution than either the standard or donut spacers, with an average of 20% more antibiotic eluted on any given day.

Cefmetazole and cefonicid. Comparative efficacy and safety in preventing postoperative infections after vaginal and abdominal hysterectomy.

A single 1-g dose of cefmetazole was compared with a single 1-g dose of cefonicid for prophylaxis in vaginal and abdominal hysterectomy to determine their efficacy and safety. The antibiotics were administered intramuscularly 15-90 minutes before the incision was made. Cefmetazole and cefonicid had similar activity against most of the aerobic organisms recovered, but cefmetazole was significantly more active against anaerobic gram-negative microorganisms. The patterns of regrowth of vaginal flora were similar in the two treatment groups. Patient demographic characteristics and surgical procedures were similar in both groups. The difference in primary prophylactic failure (e.g., cuff cellulitis) with the two study drugs (1 of 53 [1.9%] with cefmetazole and 2 of 28 [7.1%] with cefonicid) did not reach statistical significance, and the results were similar for the two routes of hysterectomy. Cefmetazole, at a dose of 1 g intramuscularly preoperatively, is a safe and effective agent for prophylaxis during hysterectomy.

A comparison of the efficacy and safety of ceftizoxime with doxycycline versus conventional CDC therapies in the treatment of upper genital tract infection with or without a mass.

It is well known that sexually transmitted infections of the upper genital tract are widespread. A variety of regimens are used to treat these conditions, many of which have not been subjected to randomized, prospective clinical trials (including the 1985 Centers for Disease Control [CDC] Guidelines for the treatment of upper genital tract infections [UGTI]). This investigation was undertaken to compare the 1985 CDC treatment guidelines with different doses of ceftizoxime, a third-generation cephalosporin with an intermediate half-life, plus doxycycline in patients with UGTI. The patients were divided into subgroups, depending on the presence or absence of a pelvic mass. Sixty-seven women participated in the study. They were older than 14 years of age and required hospitalization for the treatment of UGTI. These women had lower abdominal pain and tenderness, cervical motion or adnexal tenderness, and one of the following: temperature greater than 100.4 degrees F orally, leukocytosis greater than 10,500/mm3, or presence of a suspected inflammatory pelvic mass on pelvic examination or by ultrasound. Informed consent was obtained from all patients in a manner approved by the Institutional Review Board. Pelvic examinations and ultrasound evaluations of the pelvic soft tissues were performed on all patients at the time of admission. Those who were found not to have a pelvic mass or who had a pelvic mass less than 4 cm in transverse diameter were randomly allocated to receive either ceftizoxime 2 gm intravenously every 12 hours with doxycycline 100 mg intravenously twice daily (Rx 1, n = 13) or cefoxitin 2 gm intravenously every six hours with doxycycline 100 mg intravenously twice daily (Rx 2, n = 14). Those patients found to have a pelvic mass (greater than 4 cm in transverse diameter) were randomly allocated to receive either ceftizoxime 2 gm intravenously every eight hours with doxycycline 100 mg intravenously twice daily (Rx 3, n = 19) or clindamycin 900 mg intravenously every eight hours with a 2-mg/kg loading dose of gentamicin followed by 1.5 mg/kg intravenously every eight hours, with adjustments as necessary (Rx 4, n = 21). All UGTI patients without a mass treated with either Rx 1 or Rx 2 responded adequately. However, UGTI patients with a mass treated with Rx 4 were more likely than those treated with Rx 3 to require a change in antibiotics or need extirpative surgery in order to obtain a satisfactory clinical response (Fisher's exact test = 0.046, two-sided).(ABSTRACT TRUNCATED AT 400 WORDS)

In vitro evaluation of BL-S640, a new oral cephalosporin antibiotic.

BL-S640, a new oral cephalosporin analogue, was evaluated in vitro against 102 gram-negative and 80 gram-positive bacteria. The antimicrobial spectrum was similar to that of previous cephalosporin analogues. Good antimicrobial activity against strains of Escherichia coli, Klebsiella, staphylococci, and streptococci was demonstrated. Relatively poor activity and/or resistance was noted among most strains of Proteus, Providencia, Pseudomonas, and Serratia. In comparative studies BL-S640 had better activity against strains of Hemophilus influenzae, Staphylococcus aureus, and Enterobacteriaceae than many cephalosporin analogues. Variation of susceptibility results was dependent upon the type of media and inoculum size. Cross-resistance between BL-S640 cephalexin, cephalothin, and cefazolin was demonstrated. Among strains of Klebsiella the more rapid selection of resistance ot other cephalosporins was in contrast to BL-S640. Experience in vitro with BL-S640 has documented its antimicrobial activity,and further studies of pharmacokinetics and therapeutic efficacy are indicated.