Amoxicillin and clavulanate potassium in treating children with suppurative tonsillitis

To evaluate clinical effects of amoxicillin and clavulanate potassium in the treatment of children with suppurative tonsillitis, 146 children with suppurative tonsillitis were randomly divided into a ceftezole sodium group and an amoxicillin and clavulanate potassium group. The two groups were given anti-infection treatment using different drugs. Symptomatic treatment was carried out once symptoms such as fever appeared. Five to seven days were taken as one treatment course. Blood routine examination and the detection of C-reactive protein (CRP) were performed three days after treatment. Indexes such as the time to the relief of symptoms, the count of white blood cells, the proportion of neutrophil and CRP levels and the incidence of adverse reactions were compared between groups to evaluate the curative effect. The overall response rate of the amoxicillin and clavulanate potassium group was 94.52%, while that of the ceftezole sodium group was 78.08%; the difference was statistically significant (P<0.05). The improvement of white blood cells and CRP levels of the amoxicillin and clavulanate potassium group was more obvious than that of the ceftezole sodium group (P<0.05). The difference of the time to the improvement of symptoms between the two groups had statistical significance; the amoxicillin and clavulanate potassium group was superior to the ceftezole sodium group (P<0.05). No severe drug-related adverse reactions were observed. Amoxicillin and clavulanate potassium dispersible tablet is effective in treating children with suppurative tonsillitis as it can rapidly relieve the clinical symptoms without increasing incidence of adverse reactions.

[Approach to the crystalline characteristics of ceftezole sodium]

AIM

To study the crystalline characteristics of ceftezole sodium.

METHODS

Ceftezole sodium crystals were obtained from different solvents. X-ray diffraction, DSC, TGA, etc were used to analyze the crytals.

RESULTS

Ceftezole sodium crystal was easily obtained in isopropanol-water mixture. It consists of ceftizole sodium monohydrate, which consists of type I and type II two different crystal forms. Powder X-ray diffraction patterns showed differences between type I and the type II crystal forms. Peaks at 8 degrees and 18 degrees in diffractograms of the type I, but at 9 degrees and 18.6 degrees in the type II could be observed. Water molecules in different crystal forms had different combining condition. They lost during 35-117 degrees C in the type I form, but lost during 110-160 degrees C in the type II form.

CONCLUSION

Structure of ceftizole sodium monohydrate crystal obtained in different circumstance could be some vary, which influence upon the thermal stability of the compound. The type I crystal form is more stable than the type II.

Antibiotic prophylaxis for permanent pacemaker implantation: a meta-analysis

BACKGROUND

Infection remains a serious complication after permanent pacemaker implantation. Antibiotic prophylaxis is frequently prescribed at the time of insertion to reduce its incidence, although results of well-designed, controlled studies are lacking.

METHODS AND RESULTS

We performed a meta-analysis of all available randomized trials to evaluate the effectiveness of antibiotic prophylaxis to reduce infection rates after permanent pacemaker implantation. Reports of trials were identified through a Medline, Embase, Current Contents, and an extensive bibliography search. Trials that met the following criteria were included: (1) prospective, randomized, controlled, open or blind trials; (2) patients assigned to a systemic antibiotic group or a control group; (3) end point events related to any infection after pacemaker implantation: wound infection, septicemia, pocket abscess, purulent secretion, right infective endocarditis, inflammatory signs, a positive culture, septic pulmonary embolism, or repeat operation for an infective complication. Seven trials met the inclusion criteria. They included 2023 patients with established permanent pacemaker implantation (new implants or replacements). The incidence of end point events in control groups ranged from 0% to 12%. The meta-analysis suggested a consistent protective effect of antibiotic pretreatment (P=.0046; common odds ratio: 0.256, 95% confidence interval: 0.10 to 0.656).

CONCLUSIONS

Results of the present meta-analysis suggest that systemic antibiotic prophylaxis significantly reduces the incidence of potentially serious infective complications after permanent pacemaker implantation. They support the use of prophylactic antibiotics at the time of pacemaker insertion to prevent short-term pocket infection, skin erosion or septicemia.

[Stability of various cephalosporins in solutions. Cefazolin, cefazedone, cefaclor]

The kinetics of splitting out the substitute at C3 in the molecule of beta-lactam antibiotics such as cefazolin, cefaclor, cefazedone and others as well as that of splitting out the chlorine atom in the side radical of the cefazedone molecule was studied within wide ranges of pH and temperature. The destruction processes for all the investigated compounds were shown to be described by the 1st order equations. The values of the activation energy, pre-exponential factors and reaction order by the hydrogen ions were measured. This provided the mathematical description of the destruction processes within wide ranges of pH and temperature. An unusual mechanism of synchronous splitting out the substitute at C3 and one of the chlorine atoms in the side radical of the cefazedone molecule was observed.

[Sequestered bone infection after Kirschner wire osteosynthesis of humeral head fracture]

Percutaneous stabilization of fractures of the humeral head by K-wires is a proved therapy. This proceeding provides enough stability for early moving of the joint and has a low incidence for complications. In the case described here the special is the cause for local infection: local osteonecrosis induced by drilling-holes too close together.

Immunotoxicity of cephalosporins in mice

This study was performed in female B6C3F1 mice to confirm previously observed effects of selected cephalosporin antibiotics on nonspecific immunity, and to determine possible effects on specific acquired immunity and host resistance. Mice were treated intravenously with DQ-2556, ceftizoxime or ceftezole at 800 mg/kg/day for 3, 5, or 7 consecutive days. All three compounds increased total serum IgM levels from day 3, but had no effects on total serum IgG levels and the thymus weight. All three cephalosporin antibiotics caused a slight increase in spleen weight and splenic germinal centers were enlarged after 5- or 7-day treatments. Antibody responses to type III pneumococcal polysaccharide (S3), a T-cell-independent immunogen, and sheep red blood cells (SRBC), a T-cell-dependent immunogen, were slightly decreased after 5-day dosings with each compound, and reached significance in DQ-2556 (response to S3) and ceftizoxime (response to S3 and SRBC). None of the tested cephalosporin antibiotics altered delayed-type hypersensitivity to oxazolone or host resistance to Plasmodium yoelii, indicating that the antibiotic-treated mice retained the capacity to mount a multicomponent and sustained protective immune response. These data suggest that although cephalosporins may cause polyclonal expansion of B cells with associated increases in total serum IgM, they do not affect the tested measures of cell-mediated immunity or host resistance. The decreased IgM antibody responses to S3 and SRBC are associated with but not known to be causally related to the concurrent IgM hypergammaglobulinemia.

Antibacterial activity of cefcanel

The minimum inhibitory concentration of cefcanel, a new oral cephalosporin, has been determined for 182 clinical isolates, of which 84 were from the family Enterobacteriaceae, 45 were from the genus Streptococcus, 18 were nonfermentative rods, 25 were Haemophilus influenzae and 10 were Branhamella catarrhalis. In general, cefcanel was more active than the other cephalosporins against the species Escherichia coli, Klebsiella aerogenes and Proteus mirabilis. Among the genus Streptococcus only the enterococci were resistant to cefcanel. H. influenzae and B. catarrhalis showed also a reasonable susceptibility towards cefcanel. Oxidative rods were highly resistant to cefcanel.

Determination of cefcanel in plasma and urine by high-performance liquid chromatography using coupled columns, after administration of the new cephalosporin prodrug cefcanel daloxate hydrochloride

A rapid and sensitive high-performance liquid chromatographic method has been developed for the determination in plasma and urine of the new cephalosporin cefcanel. The method involves a simple deproteinizing step followed by separation on a coupled-column chromatographic system with ultraviolet detection. Limits of quantification were 0.2 microM for plasma samples and 2 microM for urine samples. The method has been used for the determination of cefcanel in various clinical studies.

In vitro activity of cefcanel versus other oral cephalosporins

Cefcanel is a new orally absorbed cephalosporin. Its activity was compared with that of cefuroxime, cefaclor, cephalexin, and cefixime against gram-positive and negative aerobic and anaerobic bacteria. Cefcanel had excellent activity against methicillin-susceptible Staphylococcus aureus and Staphylococcus epidermidis, MIC90 1 micrograms/ml, superior to the other oral cephalosporins. However, methicillin-resistant staphylococci were resistant, MIC greater than or equal to 16 micrograms/ml. Streptococcus pyogenes and Streptococcus pneumoniae were inhibited by 0.015-1 micrograms/ml, concentrations comparable to other cephalosporins. Clostridium spp. were inhibited by 0.25 micrograms/ml, 8- to 128-fold lower concentrations than were found for other agents, but the MICs were greater than 64 micrograms/ml for Bacteroides spp. The MIC90 for Moraxella catarrhalis was 1 micrograms/ml, similar to cefuroxime but 16-fold greater than the MICs of cefixime. Escherichia coli and Klebsiella pneumonia which were high beta-lactamase producers were resistant, MICs greater than 64 micrograms/ml, and 50% of Enterobacter cloacae and Citrobacter freundii were resistant. Cefcanel was hydrolyzed by TEM-1, TEM-3 and Moraxella Bro-1 beta-lactamases. Escherichia coli containing TEM-1, 2, 3, 5, 7, and 9 had cefcanel MICs of greater than or equal to 16 micrograms/ml. Although cefcanel inhibited gram-positive species as well as or at lower concentrations than other cephalosporins, it lacked activity against gram-negative species that produced common plasmid beta-lactamase although it inhibited Haemophilus influenzae carrying TEM-1.

Efficacy of cefcanel on staphylocci

The minimum inhibitory concentration (MIC) of cefcanel, a new oral cephalosporin, has been tested against 153 staphylococci subdivided into the species Staphylococcus aureus. S. epidermidis sensu lato and S. saprophyticus, with and without beta-lactamase production. The concentration inhibiting 50% of the strains was 0.5 mg/l for all three species while the corresponding values for 90% of the strains were 1, 2 and 1 mg/l, respectively. These values apply to all the strains. The MICs of the non-beta-lactamase-producing strains were identical to the MICs of the beta-lactamase-producing strains for S. aureus, three twofold steps lower for S. epidermidis and one step higher for S. saprophyticus. Consequently, beta-lactamase production had no consistent consequences for the activity of cefcanel against S. aureus and S. saprophyticus. In contrast, the beta-lactamase production of S. epidermidis did influence the activity of cefcanel. Among the tested cephalosporins, cefcanel had the highest antistaphylococcal activity, and no strain was resistant to this new cephalosporin.

Synthesis and mechanisms of decomposition of some cephalosporin prodrugs

The delta-3 and delta-2 methyl esters of cefazolin were synthesized. The kinetics and mechanisms of degradation of the methyl esters and the delta-3 and delta-2 isomers of pivaloyloxymethyl prodrug esters of the new cephalosporin ceftetrame (Ro 19-5247) were investigated in buffer systems and in human plasma in vitro. The major hydrolytic products of all the delta-3 and delta-2 esters were the inactive delta-2 cephalosporin free acids. The following reaction scheme describes the in vitro hydrolysis of these compounds: [formula: see text]. In addition, there was evidence of opening of the beta-lactam ring to form cephalosporoic acid when the methyl ester of cefazolin was studied in human plasma and in the presence of penicillinase. For the methyl esters, the processes represented by k12, k21, and k20 were operative in buffers; in human plasma, the processes represented by k12, k21, and k20 were operative in addition to cephalosporoic acid formation. For the isomers of the cephalosporin prodrug ester Ro 19-5248 only k12 and k20 were operative in buffers; in human plasma all pathways were operative and there was no evidence of cephalosporoic acid formation. In all cases, the processes represented by k12, k21, and k20 were subject to general and/or specific base catalysis.

Influences of cephem antibiotics on the immune response in mice

The effects of six cephem antibiotics, including ceftezole, cefmetazole, cefoxitin, cefotiam, cefoperazone, and cefotaxime, on murine humoral immunity were examined. In female BDF1 mice each cephem antibiotic was administered at a dose of 800 mg/kg/day i.v. for 7 consecutive days. Among the antibiotics tested, only ceftezole and cefoperazone induced a significant increase in serum total IgM, but not in serum total IgG. Especially in case of ceftezole, the mice developed splenomegaly due to the proliferation of IgM-producing cells in the germinal centers. The proliferation of splenic IgM-producing cells was also observed in female thymus-deficient Balb/c-nu/nu mice receiving intravenous ceftezole. Thus, the drug was indicated to enhance the polyclonal IgM production in mice by acting as a B cell mitogen. This is consistent with the in vitro finding that ceftezole exhibited a mitogenic effect on whole spleen cells from BDF1 mice, but not on B cell depleted spleen cells.

In vitro activities of cefcanel and some other cephalosporins against Pasteurella multocida

Thirty-five strains of Pasteurella multocida from humans and animals were tested for susceptibility to five cephalosporins by a broth dilution method. Cefcanel showed high activity against all isolates (MIC and MBC, less than or equal to 0.64 micrograms/ml). The corresponding figure for cefaclor and cefuroxime was 2.56 micrograms/ml. Cefadroxil and cephalexin were the least active compounds tested.

[Drug-protein binding in elderly subjects]

It is important to know the magnitude of serum-protein binding of drug dynamics in vivo. The authors investigated the effects of a variety of serum free fatty acids in elderly subjects. Serum albumin levels and ceftezole (CTZ)-protein binding in elderly subjects were lower than in younger subjects. No significant difference was noted between the two groups in regard to total free fatty acid (T-FFA) level. However, compared with younger subjects, palmitolic and oleic acid were higher and myristic and linoleic acid were lower in elderly subjects, suggesting that free fatty acid (FFA) undergoes qualitative changes due to ageing. In elderly subjects CTZ-binding correlated negatively with T-FFA, oleic acid and linoleic acid, but positively with stearic acid. Oleic acid decreased CTZ-protein binding. This decrease was higher than that due to decreased albumin levels in elderly subjects with albumin levels less than 4.0 g/dl. These findings indicated that reduced protein binding in elderly subjects is due to decreased serum albumin and changes in FFA constitution with ageing. Therefore it was suggested that drug-albumin binding may change due to the competitive action of albumin sites, and albumin-drug binding capacity. Since drug-protein binding capacity seriously affect metabolism, excretion, efficacy and side effects due to the presence of free drugs, these aspects require further investigation in elderly subjects.

Antibiotic single-dose prophylaxis of shunt infections

Shunt infections after implantation or revision of a shunt for CSF drainage in hydrocephalic patients are serious complications. In view of their frequency, this study investigated the efficacy of prophylactic administration of a single dose of the antibiotic cefazedone in reducing in the post-operative infection rate. Fifty children of up to 14 years of age suffering from hydrocephalus of various etiologies were treated prophylactically and compared with a similar untreated group. The diagnosis of infection was based mainly on microbiological and clinical observations and investigations. Classical infection parameters were also recorded and evaluated, but played only a secondary role in establishing the diagnosis as they can change post-operatively without an infection being present. The infection rates observed were 6% in the group of patients who received antibiotic treatment prophylactically and 14% in the untreated control group.

Comparative antibacterial activity of the new cephalosporin cefcanel against anaerobic bacteria

The activity of cefcanel against anaerobic cocci, Clostridium perfringens, Bacteroides fragilis, Bacteroides spp. and fusobacteria was determined by the agar dilution method and compared with the activity of cefaclor, cephalexin, cefadroxil, phenoxymethylpenicillin and ampicillin. Cefcanel showed good activity against Clostridium perfringens, Bacteroides spp. and fusobacteria (MIC90 = 1-4 mg/l). Against anaerobic cocci its MIC90 value was 16 mg/l, and against Bacteroides fragilis, 32 mg/l. Cefcanel has an antibacterial activity that warrants investigation in clinical trials.

Cephalosporin-induced changes in the ultrastructure of canine bone marrow

Fourteen healthy dogs were given 540 to 840 mg/kg of cefazedone (Refosporen) intravenously for up to 4 months or until peripheral blood cell count were depressed. Within 6 to 10 weeks treated dogs developed pancytopenia (5/14), thrombocytopenia (11/14), moderate to severe neutropenia (8/14), and/or normocytic anemia with erythroblastemia (8/14). Ultrastructural changes in bone marrow of severely cytopenic dogs included mitochondrial damage in hematopoietic and nonhematopoietic cells, thickening of endosteal bone lining layers, increased adventitial coverage of vascular sinuses, and an increased number of active macrophages. Swollen, ruptured mitochondria were in erythroid, granulocytic, and megakaryocytic cells, and, to a lesser extent, in macrophages, reticular endothelial, and bone lining cells. Maturation arrest was evident in both erythroid and granulocytic cell lines. There was also evidence of ineffective erythropoiesis and granulopoiesis. None of these changes were observed in bone marrow of controls, treated dogs that did not develop cytopenia, or dogs allowed to recover after cessation of dosing.

The hematopathology of cefonicid- and cefazedone-induced blood dyscrasias in the dog

Cephalosporin treatment in man has been associated with blood dyscrasias that include a time- and dose-related anemia, neutropenia, and thrombocytopenia, the hematopathology of which remains poorly characterized. A similar hematologic syndrome can be produced in dogs following daily intravenous injections of 540-840 mg/kg cefazedone or 400-500 mg/kg cefonicid for 1-3 months. Using this animal model, histologic and cytologic changes in blood, bone marrow, spleen, and liver were studied over the course of the cephalosporin-induced cytopenias. Peripheral blood cytologic observations included an absence, generally, of erythroid regenerative changes, increased numbers of macroplatelets, spherocytosis, erythroblastemia, and toxic neutrophil morphology. Interim and postmortem cytologic and histologic observations of bone marrow included hypoplastic and toxic changes, primarily in cytopenic dogs receiving high doses of cefonicid, and regenerative changes in hematopoietic tissue of affected cefazedone-treated animals. The latter included variable erythroid hyperplasia, increased megakaryocytes, and decreased marrow fat and was accompanied by evidence of extra-medullary hematopoiesis and increased hemosiderin and hemophagocytosis in liver and splenic tissue. The incidence and severity of these changes were dose-dependent, corresponded with the cytopenias observed peripherally, and, like the cytopenias, were fully reversible. These observations suggest that the hematologic syndrome associated with cephalosporin treatment in the dog has multiple toxicologic mechanisms, which include peripheral cytotoxic effects and bone marrow damage with depressed or ineffective hematopoiesis.

The hematologic effects of cefonicid and cefazedone in the dog: a potential model of cephalosporin hematotoxicity in man

Cephalosporin antibiotics cause a variety of hematologic disturbances in man, the pathogeneses and hematopathology of which remain poorly characterized. There is a need for a well-defined animal model in which these blood dyscrasias can be studied. In four subacute toxicity studies, the intravenous administration of cefonicid or cefazedone to beagle dogs caused a dose-dependent incidence of anemia, neutropenia, and thrombocytopenia after 1-3 months of treatment. A nonregenerative anemia was the most compromising of the cytopenias and occurred in approximately 50% of dogs receiving 400-500 mg/kg cefonicid or 540-840 mg/kg cefazedone. All three cytopenias were completely reversible following cessation of treatment; the time required for recovery of the erythron (approximately 1 month) was considerably longer than that of the granulocytes and platelets (hours to a few days). Upon rechallenge with either cephalosporin, the hematologic syndrome was reproduced in most dogs tested; cefonicid (but not cefazedone)-treated dogs showed a substantially reduced induction period (15 +/- 5 days) compared to that of the first exposure to the drug (61 +/- 24 days). This observation, along with the rapid rate of decline in red cell mass parameters of affected dogs, suggests that a hemolytic component complicated the red cell production problem and that multiple toxicologic mechanisms contributed to the cytopenia. We conclude that the administration of high doses of cefonicid or cefazedone to dogs can induce hematotoxicity similar to the cephalosporin-induced blood dyscrasias described in man and thus provides a useful model for studying the mechanisms of these disorders.

Pharmacokinetic studies on ceftezole

The adult volunteers were given 1 g of ceftezole as a single intramuscular dose to investigate the pharmacokinetic profile of this new cephalosporin. The peak average serum concentration, reached 2 h after injection, was 22.5 micrograms/ml, and the t1/2 beta was 1.5 h; urinary recovery was over 80% within 24 h, the majority of injected ceftezole being excreted within 3 hours.

In vitro activity of temocillin, moxalactam and cefotaxime against gram negative bacteria sensitive or resistant to ureidopenicillins and/or cefacedone

Minimal inhibitory concentrations (MIC's) of temocillin, cefotaxime and moxalactam were determined by agar dilution technique for 225 strains belonging to various species of Enterobacteriaceae and for 58 strains of H. influenzae and H. parainfluenzae. For Enterobacteriaceae, the MIC's of temocillin are distinctly higher than that of cefotaxime and moxalactam. But temocillin activity was not affected by resistance against ureidopenicillins and/or cefacedone. No resistant strains were encountered among E. coli, K. pneumoniae, Proteus spp. except one strain of P. vulgaris. In E. cloacae- strains with resistance against cefotaxime, temocillin was more active than moxalactam. S. marcescens- strains with a high MIC of temocillin were sensitive to cefotaxime and moxalactam. Temocillin is of the same order of activity as ampicillin against ampicillin-sensitive strains of H. influenzae and H. parainfluenzae. Its MIC is not influenced by beta-lactamases of these species.

[Clinical study on ceftezole in oral surgery. Clinical effect of ceftezole used jointly with gamma-globulin (Gamma-Venin) (author's transl)]

Ceftezole, an antibiotic of cephalosporin C derivative was applied to treatment in 39 patients with odontogenic inflammation or postoperative infections. The drug was administered intravenously (1-5 g/day) for the period of 5-10 days. Twenty of them were administered jointly with gamma-globulin (Gamma-Venin). Therefore, we compared clinically between the group of ceftezole with Gamma-Venin and the other group without it. But no difference was noticed statistically between these groups. No side effect was observed with throughout all the cases.

[Treatment of infection in the patients wih hematopoietic malignancy with ceftezole (Falomesin) (author's transl)]

Ceftezole (CTZ) was administered to 20 patients with hematopoietic malignancy complicated with infections. These patients consisted of 7 cases of AML, 2 ALL, 2 AMMoL, 1 APL, 1 blast crisis of CML, 2 HD, and 5 NHL. In 13 cases, sites of infection were determined and causative organisms were identified. In other 7 cases, sites of infection or causative organisms were unknown. In the former 13 cases, pneumonia was demonstrated in 6 patients, tonsillitis in 4 patients, pyelonephritis in 2 patients and sepsis in 1 patient. Klebsiella was separated from 5 patients as the causative organisms, E. coli from 2 patients, E. coli and Pseudomonas aeruginosa from 1 patient, Pseudomonas cepacia from 1 patient, Streptococcus viridans from 2 patients, Proteus from 1 patient and Torulopsis from 1 patient. Gram-negative rods were separated from 10 of the 13 cases (77%) as the causative organisms. CTZ was administered intravenously in dose from 4 g to 16 g per day combined with other antibiotics (AMK, GM, DKB, TOB, SBPC, CBPC, LC, ST). The response rate in 12 cases of acute leukemia and in 7 cases of malignant lymphoma was 58% and 43%, respectively. Infections occurred in 4 patients with less than 100 neutrophil per mm3 did never favorably responded even with CTZ.

[Cefazedone-results of a multicentre clinical test (author's transl)]

Cefazedone (Refosporin) was tested for efficacy and tolerance in 1161 patients. The trial was interrupted or unsuitable for evaluation in 54 cases. Diagnostical characteristics of the remaining 1107 patients tested for tolerance were: therapeutical and prophylactic use in surgery (37,5%) infections of the bronchial tract (30.8%), infections of the urogenital tract (17.9%), infections of the abdominocystic tract (6.2%), other infections (7,6%). Of the 1085 patients tested for efficacy--in 22 cases the trial was interrupted because of undesired side effects (exanthema, nausea, local intolerance)--87% concerned exclusively antibiotic therapy with cefazedone. Cefazedone was administered only twice daily i. v. Combined medication with other antibiotics--mainly amino glycosides--was highly efficient.

[Clinical studies of effectiveness of ceftezole (Falomesin 'Chugai') on the infectious disease in infancy and childhood (author's transl)]

Clinical studies of the effectiveness of ceftezole (Falomesin 'Chugai') were performed on 50 cases of infants and children with infectious disease during November 1978 and February 1979. Effective results were obtained in 86% of subjects with remarkable effect especially in the group of acute upper respiratory disease. No side effect was detected in our study while elevated mean value of platelet count was observed after medication.

Pharmacokinetics of ceftezole in patients with normal and impaired renal function

The pharmacokinetics of ceftezole, a new cephalosporin antibiotic, was studied in 15 patients with normal and impaired renal function after administering the drug in a 2-hour intravenous drip infusion of 2 g. 81% of the infused dose was excreted in the first 6 h urine of the patients with normal renal function. The pharmacokinetic parameters of ceftezole were obtained by analyzing the serum level data of the drug using a one-compartment open model. The mean serum half-life of ceftezole was 0.64 h in patients with normal renal function and was prolonged to 10.7 h in patients with severely impaired renal function (creatinine clearance: 0-2.6 ml/min.). There was a significant linear correlation between the elimination rate of the drug and creatinine clearance.

Degradation kinetics of a new cephalosporin derivative in aqueous solution

The degradation kinetics of a new cephalosporin derivative (1) in aqueous solution were investigated at 60 degrees, mu = 0.05, at pH 2.0-10.0. The observed degradation rates followed pseudo-first-order kinetics and were influenced significantly by H2O and OH- catalysis. No primary salt effect was observed in the acid region, but a positive salt effect was observed at pH 9.4. A general base catalytic effect by a phosphate buffer species was observed at pH 7-8. The pH-rate profile for I exhibited a degradation minimum at pH 6.05. The Arrhenius activation energies determined at pH 4.0 and 9.4 were 27.2 and 24.5 kcal/mole, respectively. Excellent agreement between the theoretical pH-rate profile and the experimental data supported the hypothesized degradation process. A comparison of I and cefazolin revealed close structural and stability analogies.

[Clinical experience with ceftezole (author's transl)]

Ten patients with acute urinary tract infection or acute epididymitis were treated with ceftezole (CTZ) twice daily at a dose of 1 approximately 3 by intravenous injection. The effective ratio obtained was nearly 90%. As a side effect, exanthem was observed in one patient.

The in vitro activity of ceftezol (demethylcefazolin) against dense populations of Escherichia coli

The activity of ceftezol was examined by continuous turbidimetric monitoring of dense populations of Escherichia coli exposed to the drug. Although ceftezol was found to be very active against strains of E. coli, its activity was consistently less than that of the closely related antibiotics, cefazolin. This difference was also found when strains of E. coli were examined in a dynamic system which simulates some of the conditions in which bacteria and drug interact in the treatment of bacterial cystitis. Evidence is presented that the difference in activity between the two cephalosporins resides in a differential ability to induce certain morphological changes in E. coli and in a differential rate of destruction by escherichial beta-lactamases.