In Silico Prediction of the Absorption and Disposition of Cefadroxil in Humans using an Intestinal Permeability Method Scaled from Humanized PepT1 Mice

It is difficult to predict the pharmacokinetics and plasma concentration-time profiles of new chemical entities in humans based on animal data. Some pharmacokinetic parameters, such as clearance and volume of distribution, can be scaled allometrically from rodents, mammals, and nonhuman primates with good success. However, it is far more challenging to predict the oral pharmacokinetics of experimental drug candidates. In the present study, we used in situ estimates of intestinal permeability, obtained in silico and from rat, wild-type (WT), and humanized PepT1 (huPepT1) mice, to predict the systemic exposure of cefadroxil, an orally administered model compound, under a variety of conditions. Using the GastroPlus simulation software program (Simulations Plus, Lancaster, CA), we found that the C max and area under the plasma concentration-time curve from time zero to the last measurable concentration of cefadroxil were better predicted using intestinal permeability estimates (both segmental and jejunal) from huPepT1 than from WT mice, and that intestinal permeabilities based on in silico and rat estimates gave worse predictions. We also observed that accurate predictions were possible for cefadroxil during oral dose escalation (i.e., 5, 15, and 30 mg/kg cefadroxil), a drug-drug interaction study (i.e., 5 mg/kg oral cefadroxil plus 45 mg/kg oral cephalexin), and an oral multiple dose study [i.e., 500 mg (6.7 mg/kg) cefadroxil every 6 hours]. Finally, the greatest amount of cefadroxil was absorbed in duodenal and jejunal segments of the small intestine after a 5 mg/kg oral dose. Thus, by combining a humanized mouse model and in silico software, the present study offers a novel strategy for better translating preclinical pharmacokinetic data to oral drug exposure during first-in-human studies.

Clinical Outcomes of Failing to Dose-Reduce Cephalosporin Antibiotics in Older Adults with CKD

BACKGROUND AND OBJECTIVES

Current dosing recommendations for cephalosporin antibiotics are on the basis of pharmacokinetic studies and are frequently ignored in practice. This study was undertaken to investigate the clinical outcomes of failing to dose-reduce cephalosporin antibiotics in CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Retrospective cohort study conducted in Ontario, Canada using linked population-based health care databases. Nine thousand three hundred forty-seven outpatients (median age 83; interquartile range, 77-88 years; 57% women) with an eGFR<30 ml/min per 1.73 m2 and no prior history of dialysis were dispensed oral cephalexin, cefuroxime, or cefprozil between April of 2007 and March of 2016. Two thirds of the patients (6253 of 9347) received a higher than recommended daily dose of cephalexin (>1000 mg), cefuroxime (>500 mg), or cefprozil (>500 mg). The primary outcome was a hospital encounter (emergency room visit or hospital admission) with a condition listed as a possible side-effect of cephalosporins. Secondary outcomes were antibiotic treatment failure and all-cause mortality. All measures were assessed in the 30 days after cephalosporin initiation.

RESULTS

Patients who received a higher than recommended dose of a cephalosporin antibiotic were similar in multiple indicators of baseline health to patients who received a reduced dose. Overall, 6% of patients presented to hospital with a possible cephalosporin side-effect, 13% failed antibiotic treatment, and 3% died. Compared with a reduced dose, receiving a higher dose of antibiotic was not associated with a different rate of side-effects (adjusted odds ratio, 1.00; 95% confidence interval, 0.84 to 1.20), treatment failure (1.01; 0.88 to 1.15), or death (0.99; 0.76 to 1.29).

CONCLUSIONS

In this study we failed to demonstrate any association between the dose of cephalosporin antibiotic administered to elderly patients with CKD and the risk of side-effects leading to hospitalization, treatment failure, or mortality.

Pneumatosis coli in a domestic ferret (Mustela putorius furo)

A 4-year-old spayed female ferret was presented with acute diarrhea and partial anorexia. Pneumatosis coli and segmental enteropathy were identified by ultrasonography and radiography. Fecal culture did not identify any pathogenic bacteria. Medical management of concurrent diseases and antibiotic therapy resulted in resolution of clinical signs and pneumatosis coli.

Juvenile cellulitis in a 7-week-old golden retriever dog

A 7-week-old golden retriever puppy was presented with acute onset of marked facial inflammation and pustular dermatitis, markedly enlarged submandibular lymph nodes, and pyrexia. Treatment included high-dose corticosteroids and antibiotics. One week after presentation the puppy showed a significant decrease in inflammation and healing pustules.

Prevention of surgical site infection in lower limb skin lesion excisions with single dose oral antibiotic prophylaxis: a prospective randomised placebo-controlled double-blind trial

OBJECTIVES

To determine the effectiveness of a single perioperative prophylactic 2 g dose of cephalexin in preventing surgical site infection (SSI) following excision of skin lesions from the lower limb.

DESIGN

Prospective double-blinded placebo-controlled trial testing for difference in infection rates.

SETTING

Primary care in regional North Queensland, Australia.

PARTICIPANTS

52 patients undergoing lower limb skin lesion excision.

INTERVENTIONS

2 g dose of cephalexin 30-60 min before excision.

MAIN OUTCOME MEASURES

Incidence of SSI.

RESULTS

Incidence of SSI was 12.5% (95% CI 2.7% to 32.4%) in the cephalexin group compared with 35.7% (95% CI 18.6% to 55.9%) in the placebo group (p=0.064). This represented an absolute reduction of 23.21% (95% CI -0.39% to 46.82%), relative reduction of 65.00% (95% CI -12.70% to 89.13%) and number-needed-to-treat of 4.3.

CONCLUSIONS

Administration of a single 2 g dose of cephalexin 30-60 min before skin lesion excision from the lower limb may produce a reduction in the incidence of infection; however, this study was underpowered to statistically determine this.

TRIAL REGISTRATION NUMBER

ACTRN12611000595910.

The management of acute mastoiditis in children with cochlear implants: saving the device

OBJECTIVE

Early treatment of profound bilateral sensorineural hearing loss with cochlear implantation has become routine, resulting in an increased proportion of children implanted at younger ages. These children are at a relatively high risk for acute otitis media (AOM), and are more likely to develop mastoiditis in the implanted ear. Despite the significant risks associated with mastoiditis, including compromise of the implant, there are no specific guidelines on the management of this population. We propose a treatment algorithm emphasizing early but conservative operative intervention.

METHODS

A retrospective chart review included eight patients, who experienced mastoiditis, in the context of cochlear implantation at our center from August 2005 to November 2012. During this period 806 implant surgeries were completed.

RESULTS

The median age at which mastoiditis occurred was 37 months, and the mean time from implantation to mastoiditis was 9.56 months. All patients underwent drainage of the middle ear in conjunction with intravenous antibiotics, and two additionally underwent post-auricular incision and drainage.

DISCUSSION

Recent mastoidectomy may be a risk factor for the development of a post-auricular abscess in children, who develop AOM following cochlear implantation. A treatment algorithm was developed, which emphasizes early operative drainage in conjunction with aggressive antibiotic therapy. Conclusions A consistent approach to the management of mastoiditis in children with cochlear implants has not been established. Rapid initiation of aggressive antibiotic therapy and a low threshold for conservative operative intervention results in effective resolution of infection while allowing preservation of the implant.

Community-based management and outcome of omphalitis in newborns in Karachi, Pakistan

OBJECTIVES

To describe the clinical profile and outcome in newborns with omphalitis managed with home or clinic-based therapy.

METHODS

The descriptive study was conducted from September 2004 to August 2007 in three low-income communities in Karachi, Pakistan. Newborns with omphalitis detected by community health workers through active surveillance were referred to local clinics. Those with physician-confirmed omphalitis were treated for 7 days with topical gentian violet or oral cephalexin (as monotherapy) or topical gentian violet and oral cephalexin (combination therapy) at physician discretion, or injectable therapy (procaine penicillin and gentamicin) if clinical signs of sepsis were also present and family refused hospital referral. Follow-up was at 48-72 hours and 7 days. SPSS 16 was used for statistical analysis.

RESULTS

Among 1083 newborns with omphalitis, 578 (53.4%) had peri-umbilical cellulitis without purulent discharge; 365 (33.7%) had purulent discharge (with or without cellulitis); and 140 (13%) had omphalitis with sepsis Review of outcome data at one week showed that among 943 newborns without signs of sepsis, 938 (99.5%) had improved; 2 (0.2%) died, and 2 (0.2%) were lost to follow-up. There were 5 (3.6%) therapy failures, among 140 newborns with omphalitis and sepsis managed with parenteral antibiotics at 48 hours, but 139 (99.2%) had improved by one week, while 1 (0.8%) died.

CONCLUSION

In resource-constrained environments, omphalitis can be managed in the community with minimal need for hospital referral. Further research to define optimal therapeutic regimens is needed.

[Cure rates of chronic subclinical Staphylococcus aureus mastitis in lactating dairy cows after antibiotic therapy]

Staphylococcus (S.) aureus is an important mastitis causing pathogen in dairy cows worldwide. The aim of this controlled and randomized study was to analyze the effects of an antibiotic treatment on chronic subclinical S.aureus mastitis during lactation.The study was conducted between July 2011 and December 2011 in Northern Germany including 134 udder quarters (i. e. 103 dairy cows) infected with S. aureus. The animals were randomly divided into two groups (control and treatment group). Quarter foremilk duplicate samples were taken on days 0, 7, 32 and 39 from each infected udder quarter for microbiological analysis and somatic cell count determination. Treatment consisted of cephalexin (200 mg intramammarily 5 times every 12 h) plus marbofloxacine (2 mg/kg BM subcutaneously 3 times every 24 h). "Pathogen elimination" was assessed as the status, when no S. aureus was isolated from the quarter samples of days 32 and 39. "Cure" was defined as the status, when in addition to pathogen elimination the somatic cell count of the quarter in both milk samples was below 100 000/ml. Animals of the treatment group showed a pathogen elimination rate of 35.9% and a cure rate of 21.9%. The rates for the control group were 21.4% and 8.6%, resp. The differences between groups were statistically significant. These results indicate that pathogen elimination and cure rates of chronic subclinical S. aureus mastitis are low after an intramammary cephalexin and subcutaneous marbofloxacine treatment, but still significantly better than without any antibiotic treatment.

GAPO syndrome associated with pyoderma vegetans: an unreported co-existence

GAPO syndrome is a rare autosomal recessive disease and an acronym composed of growth retardation, alopecia, pseudoanodontia, optic atrophy. Approximately 38 cases have been reported in literature until now. Pyoderma vegetans is a chronic inflammatory disease characterized with vesicopustular, exudative and vegetative lesions usually localized on face, scalp, axilla and genitalia. Pyoderma vegetans is attributed to a bacterial infection frequently occurring in individuals with an underlying immunosuppressive condition. A 30-year-old female patient was admitted to our clinic with complaint of a hemorrhagic, crusted, exudative vegetative two plaques on the scalp. On her physical examination, she had a prematurely aged face, predominant lower lips, total tooth loss, frontal bossing, enlarged anterior fontanelle, marked scalp veins, micrognatia, depressed nasal bridge, short stature, growth retardation. She was diagnosed as GAPO syndrome as the result of her physical examination. Result of the biopsy taken from scalp was evaluated as pyoderma vegetans. And the diagnosis of pyoderma vegetans was established based on the correlate of both clinical and histopathologic findings. Pyoderma vegetans coexisting with GAPO syndrome has not been reported previously. Thus we wished to report it.

Pharmacokinetics, protein binding, and tissue distribution of orally administered cefpodoxime proxetil and cephalexin in dogs

OBJECTIVE

To determine the effect of protein binding on the pharmacokinetics and distribution from plasma to interstitial fluid (ISF) of cephalexin and cefpodoxime proxetil in dogs.

ANIMALS

6 healthy dogs.

PROCEDURES

In a crossover study design, 25 mg of cephalexin/kg or 9.6 mg of cefpodoxime/kg was administered orally. Blood samples were collected before (time 0) and 0.33, 0.66, 1, 2, 3, 4, 6, 8, 10, 12, 16, and 24 hours after treatment. An ultrafiltration device was used in vivo to collect ISF at 0, 2, 4, 6, 8, 10, 12, 16, and 24 hours. Plasma and ISF concentrations were analyzed with high-pressure liquid chromatography. Plasma protein binding was measured by use of a microcentrifugation technique.

RESULTS

Mean plasma protein binding for cefpodoxime and cephalexin was 82.6% and 20.8%, respectively. Mean ± SD values for cephalexin in plasma were determined for peak plasma concentration (Cmax, 31.5±11.5 μg/mL), area under the time-concentration curve (AUC, 155.6±29.5 μg•h/mL), and terminal half-life (T½, 4.7±1.2 hours); corresponding values in ISF were 16.3±5.8 μg/mL, 878±21.0 μg•h/mL, and 3.2±0.6 hours, respectively. Mean±SD values for cefpodoxime in plasma were 33.0±6.9 μg/mL (Cmax), 282.8±44.0 μg•h/mL (AUC), and 5.7±0.9 hours (T1/2); corresponding values in ISF were 4.3±2.0 μg/mL, 575±174 μg•h/mL, and 10.4±3.3 hours, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Tissue concentration of protein-unbound cefpodoxime was similar to that of the protein-unbound plasma concentration. Cefpodoxime remained in tissues longer than did cephalexin.

A noninferiority clinical trial comparing fluconazole and ketoconazole in combination with cephalexin for the treatment of dogs with Malassezia dermatitis

This double-blinded noninferiority clinical trial evaluated the use of oral fluconazole for the treatment of Malassezia dermatitis in dogs by comparing it with use of an accepted therapeutic agent, ketoconazole. Dogs presenting with Malassezia dermatitis were treated with either fluconazole or ketoconazole in addition to cephalexin for concurrent bacterial dermatitis. Statistically significant improvements in cytologic yeast count, clinical signs associated with Malassezia dermatitis, and pruritus were seen with both antifungal treatments. There was no statistical difference between the treatments with regard to the magnitude of reduction in these parameters. These results suggest that fluconazole is at least as effective as ketoconazole for the treatment of dogs with Malassezia dermatitis.

Chronopharmacological Study of Cephalexin in Dogs

Recent studies have identified a 24 h rhythm in the expression and function of PEPT1 in rats, with significantly higher levels during the nighttime than daytime. Similarly, temporal variations have been described in glomerular filtration rate and renal blood flow, both being maximal during the activity phase and minimal during the rest phase in laboratory rodents. The aim of this study was to assess the hypothesis that the absorption of the first-generation cephalosporin antibiotic cephalexin by dogs would be less and the elimination would be slower after evening (rest span) compared to morning (activity span) administration, and whether such administration-time changes could impair the medication's predicted clinical efficacy. Six (3 male, 3 female; age 4.83+/-3.12 years) healthy beagle dogs were studied. Each dog received a single dose of 25 mg/kg of cephalexin monohydrate per os at 10:00 and 22:00 h, with a two-week interval of time between the two clock-time experiments. Plasma cephalexin concentrations were determined by microbiological assay. Cephalexin peak plasma concentration was significantly reduced to almost 77% of its value after the evening compared to morning (14.52+/-2.7 vs. 18.77+/-2.8 microg/mL) administration. The elimination half-life was prolonged 1.5-fold after the 22:00 h compared to the 10:00 h administration (2.69+/-0.9 vs. 1.79+/-0.2 h). The area under the curve and time to reach peak plasma concentration did not show significant administration-time differences. The duration of time that cephalexin concentrations remained above the minimal inhibitory concentrations (MIC) for staphylococci susceptiblity (MIC=0.5 microg/mL) was>70% of each of the 12 h dosing intervals (i.e., 10:00 and 22:00 h). It can be concluded that cephalexin pharmacokinetics vary with time of day administration. The findings of this acute single-dose study require confirmation by future steady-state, multiple-dose studies. If such studies are confirmatory, no administration-time dose adjustment is required to ensure drug efficacy in dogs receiving an oral suspension of cephalexin in a dosage of 25 mg/kg at 12 h intervals.

A retrospective review of ampicillin-sulbactam and amoxicillin + clavulanate vs cefazolin/cephalexin and erythromycin in the setting of preterm premature rupture of membranes: maternal and neonatal outcomes

OBJECTIVE

The purpose of this study was to compare the efficacy and outcomes of 2 different antibiotic regimens that are used to prolong latency in preterm premature rupture of membranes. The primary objective was to determine whether the use of ampicillin-sulbactam/amoxicillin + clavulanate was associated with an increased risk of necrotizing enterocolitis.

STUDY DESIGN

A retrospective review of pregnancies that were complicated by preterm premature rupture of membranes from 1999-2006 at 2 institutions was performed. Outcomes were compared between subjects who received parenteral ampicillin-sulbactam followed by oral amoxicillin + clavulanate (protocol A) and subjects who received parenteral cefazolin and erythromycin followed by oral cephalexin and erythromycin (protocol B).

RESULTS

There were 147 women who were evaluated; 88 women received protocol A, and 59 women received protocol B. There were no differences in latency period, gestational age at delivery, or route of delivery. The incidence of necrotizing enterocolitis was 8.0% and 10.2% for protocol A and protocol B, respectively (P = .64).

CONCLUSION

Ampicillin-sulbactam/amoxicillin + clavulanate was not associated with an increase in neonatal necrotizing enterocolitis. Erythromycin in combination with cefazolin and cephalexin is an effective latency antibiotic regimen.

Clinical, histopathological and therapeutic considerations in a flock of sheep with facial staphylococcal-associated dermatitis

In a flock of 290 sheep, a total of 20 ewes (6.9%) with an age range of 1.5-4 years, developed a nonpruritic dermatitis characterized by alopecia/hypotrichosis, erythema, hyperpigmentation, crusting, superficial ulcers, exudation and thickening of the skin that was localized mainly to the peri-ocular area. Frequent and massive feeding of swarming sucking flies on the lesional sites was witnessed. In every instance (n = 6), Staphylococcus aureus was cultured from the exudate and the aseptically obtained skin biopsy samples from both recurrent and new cases. The main predisposing factor was the presence of small troughs, which forced the sheep to compete for food. Intramuscular administration of cefalexin for 7 days resulted in the resolution of lesions over a 2-week period. No further cases or recurrences were seen over the 16-month follow-up period. The main histopathological feature of this skin disease was a superficial and deep, perivascular to interstitial eosinophilic and mononuclear dermatitis.

Metoclopramide modifies oral cephalexin pharmacokinetics in dogs

The purpose of this study was to investigate whether previous administration of metoclopramide affects cephalexin pharmacokinetics after its oral administration in dogs as well as whether these changes impair its predicted clinical efficacy. Six healthy beagle dogs were included in this study. Oral 25 mg/kg cephalexin monohydrate and intravenous 0.5 mg/kg metoclopramide HCl single doses were administered. Each dog received cephalexin or cephalexin following metoclopramide, with a 2-week washout period. Plasma concentrations of cephalexin were determined by microbiological assay. Cephalexin peak plasma concentration and area under the curve from 0 to infinity significantly increased from 18.77+/-2.8 microg/mL and 82.65+/-10.4 microg.h/mL to 21.88+/-0.8 microg/mL and 113.10+/-20.9 microg.h/mL, respectively, after pretreatment with metoclopramide. No differences between treatments were found for other pharmacokinetic parameters. Pharmacokinetic/pharmacodynamic indices calculated for highly susceptible staphylococci were similar for both experiences. Metoclopramide pretreatment may have increased cephalexin absorption by affecting its delivery to the intestine, and/or enhancing intestinal transporter PEPT1 function. Neither difference in the efficacy of cephalexin nor an increase in toxicity is expected as a result of this modification. Consequently, no dose adjustment is required in cephalexin-treated patients pretreated with metoclopramide.

Cephalexin inhibits N-formylated peptide transport and intestinal hyperpermeability in Caco2 cells

PURPOSE

Intestinal barrier integrity is diminished in critical illness and inflammatory bowel disease. Bacterial-derived N-formylated peptides, absorbed by the intestinal oligopeptide transporter, hPEPT1, are involved in the pathogenesis of disease-induced intestinal barrier dysfunction, via stimulation of polymorphonuclear leukocyte (PMN) migration. The purpose of this study was to determine if the hPEPT1 substrate, cephalexin, inhibits the absorption of the N-formylated peptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine ("fMLP"), thereby preventing hyperpermeability in Caco2 cells.

METHODS

Caco2 monolayers were grown on permeable supports. fMLP (0.1 microM) was added to apical chambers with and without cephalexin (5 and 10 mM), and fMLP effective permeability was calculated. To determine the ability of cephalexin to attenuate intestinal dysfunction, Caco2 cells were co-cultured with human PMN's in the presence of fMLP, cephalexin, and inflammatory cytokines. Monolayer integrity was assessed by measuring mannitol permeability.

RESULTS

Cephalexin 10 mM significantly reduced fMLP permeability (p=0.007). Monolayer integrity (as indicated mannitol permeability) was decreased in cultures treated with inflammatory cytokines and fMLP, an effect that was attenuated by cephalexin (p<0.01).

CONCLUSION

Cephalexin inhibits fMLP transport across cultured intestinal monolayers, and partially attenuates PMN-induced intestinal hyperpermeability. The use of pharmacologic hPEPT1 substrates may represent a novel means of preserving intestinal barrier integrity.

Success of short-course parenteral antibiotic therapy for acute osteomyelitis of childhood

The outcome of acute osteomyelitis treated with sequential therapy consisting of a short course of parenteral antibiotics, followed by oral antibiotics, was studied. To be considered acute osteomyelitis, related symptoms must have been present for less than 2 weeks before diagnosis. Short-course parenteral antibiotics (therapy for 7 days or less) and then oral antibiotics were used to treat 29 patients (median age, 6.3 years). Pathogens were identified from blood cultures and bone aspirates. Staphylococcus aureus was isolated in 59%. Median duration of parenteral antibiotics and oral antibiotics was 4 days (range, 0-7 days) and 28 days (range, 14-42 days), respectively. Median duration of combined (parenteral and oral) therapy was 32 days (range, 20-49 days). No failures or complications were noted at the 6-month follow-up, which was available for 27 patients. Short-course parenteral antibiotic therapy followed by oral therapy appears to be effective for treatment of acute, uncomplicated osteomyelitis.

Pyoderma caused by Pseudomonas aeruginosa infection in dogs: 20 cases

In this report we describe the historical, clinical, histopathological and microbiological features, as well as treatments and clinical outcome, of pyoderma where Pseudomonas aeruginosa alone was isolated on bacterial culture from lesional skin. Twenty dogs were included in this retrospective study. Seven dogs without prior history of systemic or skin disease presented with acute deep pseudomonal pyoderma characterized by a sudden onset of dorsal truncal pain. Skin lesions in these dogs consisted of erythematous papules, haemorrhagic bullae, ulcers and haemorrhagic crusts confined to the dorsum. An excellent clinical response was achieved with 3-4 weeks of treatment with oral fluoroquinolones. Thirteen dogs with a more gradual onset of skin lesions associated with pseudomonal pyoderma had a history of prior skin, ear or systemic disease and had previously been treated with antibiotics and/or immunomodulatory drugs. Skin lesions in these dogs were variable and similar to those described for superficial and deep staphylococcal pyoderma. In this group, one dog was euthanized prior to commencement of treatment, two dogs were lost to follow up, and 9 had resolution of lesions following treatment with topical silver sulfadiazine (one dog), fluoroquinolones (six dogs) or cephalexin (two dogs) administered orally for 3 to 12 weeks. Rod-shaped bacteria were not always detected on cytology. Histopathology of dogs with deep pseudomonal pyoderma was characterized by severe perforating suppurative folliculitis and furunculosis.

Retapamulin ointment twice daily for 5 days vs oral cephalexin twice daily for 10 days for empiric treatment of secondarily infected traumatic lesions of the skin

INTRODUCTION

Retapamulin is a novel, topical antibacterial of the pleuromutilin class in development for the treatment of secondarily infected traumatic lesions of the skin.

METHODS

The efficacy, safety, and tolerability of topical retapamulin ointment, 1% for 5 days twice daily was evaluated in 2 identical, randomized, double-blind, double-dummy, multicenter studies vs oral cephalexin, 500 mg twice daily for 10 days, in 1904 patients with secondarily infected traumatic lesions.

RESULTS

Clinical success rates were 89.5% in protocol-adherent patients receiving retapamulin compared with 91.9% for cephalexin (treatment difference, -2.5% [95% confidence interval, -5.4% to 0.5%]). In patients with Staphylococcus aureus or Streptococcus pyogenes at baseline, clinical success was 89.2% (365/409) for retapamulin and 92.6% (63/68) for cephalexin. Safety and tolerability were similar between treatments. Noncompliance (defined as using or taking <80% of doses) was recorded in 8.0% (51/636) of patients taking cephalexin compared with 0.39% (5/1268) of patients receiving retapamulin.

CONCLUSIONS

Retapamulin offers a novel, effective, and convenient topical treatment for secondarily infected traumatic lesions.

Successful treatment of recalcitrant necrotizing eosinophilic folliculitis using indomethacin and cephalexin

A 56-year-old man presented with a 4-month history of a painful and pruritic eruption consisting of crusted plaques and blisters on his face, scalp and chest. The patient suffered from headaches and malaise but was afebrile. Two skin biopsies revealed an epidermis which was eroded and covered by locules of serum and neutrophils. In the underlying dermis, there was a marked mixed inflammatory reaction including lymphocytes, neutrophils and numerous eosinophils. There was exocytosis of eosinophils into several follicles with areas of follicular mucinosis. A diagnosis of necrotizing eosinophilic folliculitis was made based upon the clinical and histopathological findings. The diagnosis was supported by the rapid response to a combination of indomethacin and cephalexin. The patient has taken continuous indomethacin (with rabeprazole and misoprostol cover) and cephalexin for 2 years. If treatment is withdrawn he experiences a flare of his disease within 2 weeks. This case highlights the potentially chronic nature of this disease.

Urinary Bactericidal Activity of Oral Antibiotics against Common Urinary Tract Pathogens in an ex vivo Model

BACKGROUND

In this investigation, the urine samples obtained in a single oral-dose pharmacokinetic study were examined for their bactericidal activity against a range of relevant urinary tract pathogens.

METHODS

Six healthy volunteers received a single oral dose of ten oral antibiotics available in Croatia. Urine samples were taken every 2 h during the whole dosing interval of the particular antibiotic. The urinary bactericidal activity was tested by determination of urinary bactericidal titers.

RESULTS

All antibiotics showed a significant urinary bactericidal activity against non-extended spectrum beta-lactamase Escherichia coli and Proteus mirabilis. Fluoroquinolones displayed high and persisting levels of urinary bactericidal activity against all gram-negative bacteria and Staphylococcus saprophyticus.

CONCLUSIONS

Average urinary bactericidal activity can be predicted from in vitro susceptibility testing, but we expect that there will be patients with a low level of urinary bactericidal activity.

Topical retapamulin ointment (1%, wt/wt) twice daily for 5 days versus oral cephalexin twice daily for 10 days in the treatment of secondarily infected dermatitis: results of a randomized controlled trial

BACKGROUND

New antibacterial agents with activity against pathogenic strains resistant to established antibiotics are needed to treat patients with secondarily infected dermatitis (SID).

OBJECTIVE

We sought to determine the clinical safety and efficacy of topical retapamulin ointment 1% versus oral cephalexin for the treatment of SID.

METHODS

Patients with SID were randomly assigned to retapamulin ointment 1% (twice daily [bid]) for 5 days, or oral cephalexin (500 mg bid) for 10 days. The primary efficacy end point was clinical response at follow-up. Secondary outcomes included microbiologic response at follow-up, safety, and compliance.

RESULTS

Retapamulin was as effective as cephalexin (clinical success rates at follow-up: 85.9% and 89.7%, respectively). Microbiologic success rates at follow-up were 87.2% for retapamulin and 91.8% for cephalexin. Retapamulin was well tolerated and the topical formulation was preferred over the oral drug.

LIMITATIONS

An imbalance existed in the number of patients with the clinical outcome "unable to determine" (15 retapamulin, 2 cephalexin), mainly because of their failure to attend the study visit. If those who failed to attend visits (who did not withdraw as a result of drug-related events) are removed from the analysis, the clinical success rates are 89.9% for retapamulin and 89.7% for cephalexin.

CONCLUSIONS

Retapamulin ointment 1% (bid) for 5 days was as effective as oral cephalexin (bid) for 10 days in treatment of patients with SID, and was well tolerated.

An outpatient medical treatment protocol for peritonsillar abscess

Several surgical methods are used to treat peritonsillar abscess, but no protocol for outpatient medical treatment has yet been published. Between February 2002 and February 2005, we treated 98 peritonsillar abscess patients with an outpatient medical regimen that involved hydration, antibiotics, steroids, and good pain control. All patients were Native Americans, who are known to have a particularly high incidence of peritonsillar abscess. The medical regimen was generally successful, as only 4 patients (4.1%) subsequently required post-treatment needle aspiration or incision and drainage. We conclude that the medical protocol described herein provides practitioners with a viable noninvasive alternative for treating peritonsillar abscess.

Controlled release of cephalexin through gellan gum beads: Effect of formulation parameters on entrapment efficiency, size, and drug release

Gellan gum beads containing cephalexin were prepared by extruding the dispersion of cephalexin and gellan gum into a solution containing a mixture of calcium and zinc ions (counterions). Beads were prepared by changing experimental variables such as pH of the counterion solution and amount of cephalexin loading in order to optimize process variables on the final % drug entrapment efficiency, release rates, size, and morphology of the beads. Absence of chemical interactions between drug, anionic polymer, and counterions after production of beads was confirmed by Fourier transform infrared spectroscopy. Differential scanning calorimetry was used to understand the crystalline nature of the drug after its successful entrapment. These data indicated the amorphous dispersion of cephalexin in the polymer matrix. Beads were spherical in shape, with the average bead size ranging from 925 to 1183 microm as measured by the laser light scattering technique. Cephalexin entrapment of up to 69.24% was achieved. In vitro release studies were performed in 0.1 N HCl or pH 7.4 phosphate buffer and the release of cephalexin was achieved up to 6 h. Dynamic swelling studies were performed in 0.1 N HCl or pH 7.4 phosphate buffer. Diffusion coefficients were calculated for spherical geometry. The release data have been fitted to an empirical relation to estimate the transport parameters. Mathematical modeling studies were performed for spherical geometry by solving Fick's equation to compute concentration profiles. These results were correlated with the release profiles.

Transfer of Probenecid and Cephalexin into Breast Milk

Objective:

To report a case of the transfer of probenecid and cephalexin into human milk.

Case Summary:

A breast-fed infant of a 30-year-old woman being treated with oral probenecid and cephalexin for a breast infection developed severe diarrhea and associated symptoms. To investigate whether the maternal drug treatment was causative, milk was collected over a dose interval at steady-state, and concentrations of probenecid and cephalexin were measured by HPLC. The average concentrations of probenecid and cephalexin in milk were 964 and 745 μg/L, respectively, corresponding to absolute and relative infant doses of 145 μg/kg/day and 0.7% for probenecid and 112 μg/kg/day and 0.5% for cephalexin. The infant's adverse effects were rated as possible for probenecid and probable for cephalexin based on the Naranjo probability scale.

Discussion:

On the basis of the calculated relative infant doses for both probenecid and cephalexin in milk and the notional 10% level of concern for infant exposure, neither drug would be expected to cause significant systemic effects. However, local adverse effects, notably diarrhea, were observed. The Naranjo probability scale rating suggested that cephalexin was more likely than probenecid to be the cause of the infant's diarrhea.

Conclusions:

When using cephalexin/probenecid to treat breast infections in lactating women, clinicians should anticipate the possibility of adverse gastrointestinal effects in the breast-fed infant.

Effects of doxycycline, amoxicillin, cephalexin, and enrofloxacin on hemostasis in healthy dogs

OBJECTIVE

To determine the effects of enteral administration of doxycycline, amoxicillin, cephalexin, and enrofloxacin at therapeutic dosages for a typical duration on hemostatic variables in healthy dogs.

ANIMALS

14 Beagles.

PROCEDURE

Doxycycline (10 mg/kg, PO, q 12 h), amoxicillin (30 mg/kg, PO, q 12 h), cephalexin (30 mg/kg, PO, q 12 h), and enrofloxacin (20 mg/kg, PO, q 24 h) were administered in random order to 10 healthy dogs at standard therapeutic dosages for 7 days, with a 7-day washout period between subsequent antimicrobials. In addition, 4 Beagles served as control dogs. Variables were evaluated before and after antimicrobial administration; they included platelet count, Hct, 1-stage prothrombin time (PT), activated partial thromboplastin time (PTT), fibrinogen concentration, and platelet function. Platelet function was assessed via buccal mucosal bleeding time, aggregation, and a platelet-function analyzer.

RESULTS

Administration of all antimicrobials caused a slight prolongation of 1-stage PT and activated PTT and slight decrease in fibrinogen concentration. Cephalexin caused a significant increase in 1-stage PT and activated PTT, amoxicillin caused a significant increase in activated PTT, and enrofloxacin caused a significant decrease in fibrinogen concentration. Platelet count or function did not differ significantly after administration of any antimicrobial.

CONCLUSIONS AND CLINICAL RELEVANCE

Oral administration of commonly used antimicrobials in healthy dogs resulted in minor secondary hemostatic abnormalities, with no change in platelet count or function. Although these changes were clinically irrelevant in healthy dogs, additional studies of the effects of antimicrobial administration on hemostasis in animals with underlying disease processes are warranted.

Community-acquired methicillin-resistant Staphylococcus aureus skin infection presenting as a periumbilical folliculitis

Community-acquired methicillin-resistant Staphylococcus aureus (CAMRSA) infection is a clinical problem of increasing global incidence. CAMRSA most commonly presents as abscess and cellulitis of the skin and soft tissue. However, the lesions of cutaneous CAMRSA infection are pleomorphic and may appear as erythematous pustules of superficial folliculitis. This report presents the cases of 2 patients with CAMRSA skin infection that presented as a superficial folliculitis. The distribution of CAMRSA-related, erythematous, folliculocentric pustules was periumbilical, in contrast to the lesional location of methicillin-susceptible S. aureus (MSSA)-associated folliculitis, which typically appears on the axillae, bearded area, buttocks, and extremities. CAMRSA should be considered in the diagnosis of periumbilical folliculitis or superficial folliculitis arising in areas not typically affected by MSSA-related folliculitis, such as the chest, flanks, and scrotum.

Pharmacokinetics and tissue fluid distribution of cephalexin in the horse after oral and i.v. administration

The purpose of this study was to determine the pharmacokinetics and tissue fluid distribution of cephalexin in the adult horse following oral and i.v. administration. Cephalexin hydrate (10 mg/kg) was administered to horses i.v. and plasma samples were collected. Following a washout period, cephalexin (30 mg/kg) was administered intragastrically. Plasma, interstitial fluid (ISF) aqueous humor, and urine samples were collected. All samples were analyzed by high-pressure liquid chromatography (HPLC). Following i.v. administration, cephalexin had a plasma half-life (t(1/2)) of 2.02 h and volume of distribution [V(d(ss))] of 0.25 L/kg. Following oral administration, the average maximum plasma concentration (C(max)) was 3.47 mug/mL and an apparent half-life (t(1/2)) of 1.64 h. Bioavailability was approximately 5.0%. The AUC(ISF):AUC(plasma) ratio was 80.55% which corresponded to the percentage protein-unbound drug in the plasma (77.07%). The t(1/2) in the ISF was 2.49 h. Cephalexin was not detected in the aqueous humor. The octanol:water partition coefficient was 0.076 +/- 0.025. Cephalexin was concentrated in the urine with an average concentration of 47.59 microg/mL. No adverse events were noted during this study. This study showed that cephalexin at a dose of 30 mg/kg administered orally at 8 h dosage intervals in horses can produce plasma and interstitial fluid drug concentrations that are in a range recommended to treat susceptible gram-positive bacteria (MIC < or = 0.5 microg/mL). Because of the low oral bioavailability of cephalexin in the horse, the effect of chronic dosing on the normal intestinal bacterial flora requires further investigation.

Pharmacokinetics of two once-daily parenteral cephalexin formulations in dogs

The aims of this study were to describe and compare the pharmacokinetic profiles and T(>MIC90) of two commercially available once-daily recommended cephalexin formulations in healthy adult dogs administered by the intramuscular (i.m.) route. Six beagle dogs received a 10 mg/kg dose of an 18% parenteral suspension of cephalexin of laboratory A (formulation A) and laboratory B (formulation B) 3 weeks apart. Blood samples were collected in predetermined times after drug administration. The main pharmacokinetic parameters were (mean +/- SD): AUC((0-infinity)), 72.44 +/- 15.9 and 60.83 +/- 13.2 microg.h/mL; C(max), 10.11 +/- 1.5 and 8.50 +/- 1.9 microg/mL; terminal half-life, 3.56 +/- 1.5 and 2.57 +/- 0.72 h and MRT((0-infinity)), 5.86 +/- 1.5 and 5.36 +/- 1.2 h for formulations A and B, respectively. T(>MIC90) was 63.1 +/- 14.7 and 62.1 +/- 14.7% of the dosing interval for formulations A and B, respectively. Median (range) for t(max) was 2.0 (2.0-3.0) h and 3.0 (2.0-4.0) for formulations A and B, respectively. Geometric mean ratios of natural log-transformed AUC((0-infinity)) and C(max) and their 90% confidence intervals (CI) were 0.84 (0.72-0.98) and 0.83 (0.64-1.07), respectively. The plasma profiles of cephalexin following the administration of both formulations were similar. No statistical differences between pharmacokinetic parameters or T(>MIC90) were observed, however, bioequivalence between both formulations could not be demonstrated, as lower 90% CI failed to fell within the selected range of 80-125% for bioequivalence.

Routine use of antimicrobials by pregnant Indian women does not improve birth outcome: a randomized controlled trial

Low birth-weight is a leading health problem in developing countries. In a randomized controlled trial, the effect of antimicrobials in pregnant women on improving birth-weight and duration of gestation was evaluated. Two hundred twenty-four pregnant women in their second trimester were randomized to receive metronidazole (200 mg 3 times daily for 7 days) and cephalexin (500 mg twice daily for 5 days) orally by one group. The mean (+/-SD) birth-weights were 2,545 g (+/-374) and 2584 g (+/-358, p=0.51), the low birth-weight rates (<2.5 kg) were 40% and 36% (p = 0.28), and the prematurity rates were 8% and 11% (p = 0.6) in the treated group and the control group respectively. Due to small sample size, it is cautiously concluded that routine antimicrobials for genital and urinary tract infections of pregnant women do not improve birth-weight or duration of gestation. Rather an unexpected observation was the proportion requiring caesarian section or forceps, which was five-fold higher in the treated group (p = 0.001), and given no plausible explanations, this finding needs confirmation. Stunted mothers (<25th centile or 146.4 cm) had two-fold higher risk for low birth-weight (p = 0.04) and assisted delivery (p = 0.1). Low maternal body mass index (<25th centile or 18) had six-fold higher risk for stillbirth or abortion (p = 0.007), and high body mass index (>75th centile or 21.2) had three-fold higher risk for assisted delivery (p = 0.003).

A Prospective Study of Antibiotic Efficacy in Preventing Infection in Reduction Mammaplasty

BACKGROUND

The role of prophylactic antibiotics in reduction mammaplasty remains controversial. However, most surgeons choose to use antibiotics. In addition to cost and potential allergic reactions, unnecessary administration of antibiotics can suppress host natural flora and produce resistant organisms.

METHODS

Fifty patients were sequentially assigned to one of three study limbs: (1) no antibiotics, (2) preoperative antibiotics only, or (3) preoperative and postoperative antibiotics. The study was designed to include approximately 17 patients in each group. Cephalosporin antibiotics were used unless there was any question of allergy, in which case an alternative antibiotic regimen was used. Preoperative data collected on patients included age, body mass index, history of diabetes mellitus, peripheral vascular disease, previous breast surgery, steroid therapy, and tobacco use. Operative data included specimen weight, operative time, estimated blood loss, prolonged intraoperative hypotension, adjunctive axillary and breast tail liposuction, and intraoperative breast tissue culture.

RESULTS

The patient population in the three limbs of the study was similar. Thus, there was no significant difference among the groups insofar as the preoperative data were concerned (p > 0.20): age, body mass index, diabetes mellitus, peripheral vascular disease, previous breast surgery, and steroid or tobacco use. Furthermore, no significant difference (p > 0.12) was noted among intraoperative data in the three groups: specimen weight, operative time, estimated blood loss, prolonged hypotension, adjunctive breast liposuction, and positive bacterial culture from intraoperative breast tissue samples. Ninety percent of positive intraoperative breast tissue cultures revealed Staphylococcus epidermidis. Using strict criteria, the infection rate ranged from 19 to 20 percent. There was no significant difference (p > 0.91) in rate of infection among the three study limbs. There was, however, a significant reduction (p = 0.002) in delayed wound healing in the group that received preoperative antibiotics only. Among the studied risk factors for infection, only positive intraoperative culture of breast tissue was significant (p = 0.008) for development of infection. There was a significant association between delayed wound healing and infection (p = 0.003).

CONCLUSIONS

This prospective study did not find that prophylactic antibiotics in reduction mammaplasty have an effect on infection; however, a single preoperative dose significantly improved wound healing.

Comparison of the clinical efficacy of oral terbinafine and ketoconazole combined with cephalexin in the treatment of Malassezia dermatitis in dogs - a pilot study

The purpose of this randomized, single blinded clinical trial was to evaluate cytologically and clinically the efficacy of oral cephalexin alone and its combination with terbinafine or ketoconazole for the treatment of Malassezia dermatitis in dogs. Twenty-two client-owned dogs with Malassezia dermatitis completed the 3-week study. All received cephalexin (generic, 250 mg or 500 mg) at 22-30 mg kg(-1) twice daily. Eight dogs received terbinafine at 30 mg kg(-1) once daily and seven dogs received ketoconazole (generic, 200 mg) at 5-10 mg kg(-1) twice daily. The remaining seven dogs received cephalexin alone. At week 0 (visit 1) and week 3 (visit 2), mean yeast counts were determined from three affected areas using tape-strip cytology, a clinical index score (CIS) was assigned to the affected areas, and owners evaluated pruritus using a visual analogue scale. All groups showed reduction in mean yeast counts, CIS and pruritus. There was an 86.8%, 80.2% and 28.8% reduction in mean yeast counts from visit 1 to visit 2 for the terbinafine, ketoconazole and cephalexin-only groups, respectively. However, within treatment group comparisons a significant reduction in mean yeast count was only evident for the terbinafine (P < 0.002) and ketoconazole (P < 0.01) groups. Pruritus reduction was only significant for the terbinafine group. These preliminary results suggest that terbinafine should be further assessed for the treatment of canine Malassezia dermatitis.

A randomized crossover study investigating the influence of ranitidine or omeprazole on the pharmacokinetics of cephalexin monohydrate

Limited data characterize pharmacokinetic interactions between cephalexin and ranitidine, and no data exist for an interaction with proton pump inhibitors. The purpose of this study was to investigate the effects of ranitidine or omeprazole administration on the pharmacokinetics and pharmacodynamics of cephalexin. A randomized single- and multiple-dose crossover study was conducted in healthy subjects ingesting cephalexin before and after steady-state administration of ranitidine or omeprazole. Time-concentration profiles were determined and pharmacokinetic parameters were characterized using noncompartmental methods. Pharmacokinetic data were analyzed in accordance with the two 1-sided test for bioequivalence. The percentage of time that serum concentrations remain above the MIC(90) during the dosing interval (T > MIC(90)) for Streptococcus pyogenes and Staphylococcus aureus associated with the pharmacokinetic profiles was calculated. The coadministration of cephalexin with ranitidine or omeprazole resulted in relatively minor changes in C(max), AUC(infinity), t(1/2), or CL/F. t(max) was significantly prolonged when cephalexin was administered with ranitidine or omeprazole. Suboptimal T > MIC(90) was observed for cephalexin irrespective of acid suppression. Delay in absorption of cephalexin resulted in a decrease in the percentage of T > MIC(90) for certain acid-suppressive regimens and pathogen combinations. With the exception of an increase in t(max), there were no significant pharmacokinetic interactions between cephalexin and ranitidine or omeprazole. Delayed t(max) associated with acid suppression may result in a diminished T > MIC(90).

Dissolution of infection-induced struvite bladder stones by using a noncalculolytic diet and antibiotic therapy

An 8-year-old, female spayed miniature schnauzer was presented for pollakiuria and gross hematuria. Infection-induced struvite urolithiasis with concurrent bacterial urinary tract infection was diagnosed. The treatment is described, followed by a brief discussion of struvite stones and their medical management.

[Means of purification of cephalexin with a view to therapeutic use]

Cephalexin (CEX) is the generic word of chemical compound 7-(D-alpha-aminophenylacetamido)-3-methyl-3-cephem-4-carboxylic acid, which is part of first generation oral cephalosporins group. It is use as cephalexin monohydrochloride monohydrate (CEX.HCl.H2O) syrup or tablets for oral administration. For obtaining a compound with great solubility and osmotic pressure, which is ideal for pharmaceutical forms with controlled dosage, it is necessary to achieve the crystalline form of Cephalexin monohydrochloride monohydrate. The therapeutic use Cephalexin has an output over 95 %, so it is necessary to purify CEX depending on it's isoelectric pH (pKa), which is 4.2. A good purification took place at greater or less values of pH, then the isoelectric pH value of CEX. The purification of CEX at greater values of pH then isoelectric point, took place with a greater output (75-76%), and the obtaining Cephalexin is much pure (97-98%).

[Immunomodulating, antioxidant and hepatoprotective effects of immobilized dosage forms of rifampicin and cephalexin]

The aim of the study was to lower the immunosuppressory, prooxidant and hepatotoxic effects of rifampicin and cephalexin by their immobilization in erythrocyte vehicles. The experiments were performed on Wistar rats with the use of rifampicin, cephalexin and lysozyme (ZAO Ferane) and hemodes (6% aqueous saline solution of low molecular polyvinylpyrrolidone, mol. wt. 12600+/-2700). Rifampicin- and cephalexin-entrapped erythrocytes were prepared. Spectrophotometric procedures for quantitative assay of the immobilized antibiotics were developed. The impact of the solution concentration and incubation time on the level of the antibiotic entrapping was studied. The erythrocyte vehicles were shown to be able to entrap the antibiotics for 9 days and to preserve their stability for 24 hours. It was observed that the increase of the immunosuppressory, prooxidant and hepatotoxic effects of the antibiotics administered without the vehicles to the laboratory animals infected by staphylococci was dose-dependent. The use of the antibiotics entrapped in the erythrocyte vehicles stimulated the immune reactivity of the animals and normalized the indices of lipid peroxidation, the antioxidant system, cytolysis and cholestasis.

Intra- and interindividual variabilities of valacyclovir oral bioavailability and effect of coadministration of an hPEPT1 inhibitor

Variability in valacyclovir bioavailability and the potential for cephalexin-valacyclovir interaction were evaluated. The intraindividual acyclovir area under the concentration-time curve (AUC) varied minimally, whereas interindividual differences were substantial. Coadministration of the human peptide transporter 1 (hPEPT1) substrates valacyclovir and cephalexin minimally reduced the acyclovir AUC. These results suggest a stable valacyclovir absorption phenotype, significant interindividual variability, and minimal interaction between these hPEPT1 substrates.

Combination effects of cephalexin and gentamicin on Edwardsiella tarda and Streptococcus iniae

The objective of this study was to determine the in vitro activity of cephalexin-gentamicin combination by a microbroth chequerboard technique against clinical isolates of Edwardsiella tarda and Streptococcus iniae. Gentamicin was shown more susceptible than cephalexin against both bacteria. The effect of cephalexin-gentamicin combination against both bacteria represented additive interaction. The combination even showed synergic interaction (22%) against E. tarda, with a FIC index of <0.5 as a borderline. No antagonism for cephalexin-gentamicin combination was observed for any bacterial strain.

Efficacy of cephalexin two vs. three times daily vs. cefadroxil once daily for streptococcal tonsillopharyngitis

The purpose of this study was to compare the bacteriologic and clinical efficacy of oral cephalexin twice vs. three times daily vs. cefadroxil once daily as therapy for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis. A prospective open-label, observational cohort study was conducted over 18 months (January 2000-June 2001). Children enrolled had an acute onset of symptoms and signs of a tonsillopharyngeal illness and a laboratory-documented GABHS infection. Follow-up examination and laboratory testing occurred 21 +/- 4 days following enrollment. Two hundred seventy-one patients were enrolled (intent to treat group): 63 received cephalexin twice daily, 124 received cephalexin three times daily, and 84 received cefadroxil once daily. Fifty-three children did not return for the follow-up visit, leaving 218 patients in the per-protocol group: 54 cephalexin twice-daily treated, 94 cephalexin 3-times daily treated, and 70 cefadroxil once-daily treated. In the per-protocol group, bacteriologic cure for those treated with cephalexin twice daily was 87%, for cephalexin 3 times daily, it was 81% and for cefadroxil once daily it was 81% (p = 0.61). The clinical cure rate for cephalexin twice-daily treatment was 91%; for three-times daily, it was 86%; and for cefadroxil once daily, it was 84% (p = 0.56). Because treatment allocation was not randomized, logistic regression analysis was used to adjust for treatment group differences. Younger age of patient was significantly associated with bacteriologic (p = 0.04) and clinical (p = 0.01) failure independent of treatment group but in the adjusted logistic model no differences were found among the 3 treatment regimens. Cephalexin dosed twice daily or three times daily and cefadroxil dosed once daily appear equivalent in bacteriologic and clinical cure of GABHS tonsillopharyngitis.

Effects of an ethyl lactate shampoo in conjunction with a systemic antibiotic in the treatment of canine superficial bacterial pyoderma in an open-label, nonplacebo-controlled study

An open-label, nonplacebo-controlled study was designed to compare systemic cephalexin therapy versus systemic cephalexin and ethyl lactate shampoo therapy in the treatment of canine superficial bacterial pyoderma. Twenty client-owned dogs diagnosed with generalized superficial bacterial pyoderma (SP) were alternately assigned to oral treatment with cephalexin (25 to 30 mg/kg every 12 hours) or treatment with cephalexin (as for Group 1) and twice-weekly shampooing with a 10% ethyl lactate shampoo, which was left in contact with the dog's skin for 10 minutes. On Days 14 and 28, skin lesion severity scores, assessed by the investigators, were significantly (P <.01) lower for the group treated with cephalexin and shampoo than for the group treated with cephalexin only. On Day 14, dog owners gave better scores to dogs treated with cephalexin and shampoo for haircoat appearance and body odor than for dogs treated only with cephalexin. Clinical and cytologic resolution of SP occurred significantly (P <.02) sooner in the cephalexin/shampoo group (29.4 days) than in the cephalexin only group (37.8 days).

Residue persistence in sheep milk following antibiotic therapy

Drug residues in milk supplies may have public health implications and can interfere in the manufacture of dairy products, such as cheese. In Spain, most ewe milk production is destined for cheese making, often using raw milk. This study analyses the main factors influencing antibiotic depletion time in lactating dairy sheep. 42, Manchega ewes were distributed into three groups, each receiving a different treatment (cephalexin intramammary infusion, penicillin G intramuscular, and oxytetracycline intravenous injections). During and after the recommended withdrawal period, milk samples were taken at each milking. A microbiological inhibition test (Brilliant Black Reduction, BRT) was used to screen all samples and antibiotic withholding times were established using a logistic regression model. The response to the BRT method in milk from individual ewes treated showed that the effect of the milking order was significant (P<0.001) with the three antibiotics. However the only influence on milk yield was with the intramammary treatment (P<0.005). The BRT method was found to be very sensitive, particularly to the two beta-lactamic antibiotics.

Influence of a new prophylactic antibiotic therapy on the incidence of liver abscesses after chemoembolization treatment of liver tumors

Intrahepatic abscess is a complication of transcatheter arterial chemoembolization (TACE) treatment in patients who have a history of biliary reconstructive surgery. This study followed eight patients who underwent chemoembolization after biliary surgery. These patients were divided into two groups. Patients in group one (n = 4) were administered intravenous cephalexin for prophylaxis. Patients in group two (n = 4) were administered bowel preparation and tazobactam/piperacillin. All patients in group one developed hepatic abscesses, which were treated with percutaneous catheter drainage and antibiotics. None of the patients in group two developed abscesses. Aggressive antibiotic prophylaxis with bowel preparation may provide protection against intrahepatic abscesses after chemoembolization in patients who have a history of biliary reconstructive surgery.

Update on prosthetic joints, dental treatment, and antibiotic prophylaxis

At this time, all dentists and physicians should be very familiar with the 1997 ADA/AAOS antibiotic prophylaxis recommendations for joint prosthesis patients who are undergoing dental treatment. The guidelines identify physical conditions that place joint replacement patients at the highest risk for joint sepsis. They also stratify dental procedures into higher-risk and lower-risk categories. Combining these two groupings clarifies the dentist's strategy for antibiotic prophylaxis protocols, which are greatly simplified over previous practices. Of notable importance is the elimination of posttreatment antibiotic dosing, the reduction of the loading dose of antibiotic, and the identification of a large group of joint replacement patients who do not require antibiotic prophylaxis prior to dental treatment. Every dentist must use clinical judgment, knowledge of the patient, and consultation with the attending physician to determine the appropriate treatment plan.

[Pharmacokinetics of cephalexin from two oral formulations in dogs]

Six beagle dogs were treated with cephalexin-monohydrate from 2 oral formulations (Rilexine tablets and Cefaseptin dragees, respectively) in a dosage of 25 mg/kg and plasma concentrations of cephalexin were measured over 8 hours. After solid phase extraction of the samples, cephalexin was determined by high pressure liquid chromatography with UV detection. After administration, Cephalexin was absorbed rapidly and mean maximum plasma concentrations of 30.9 and 27.9 micrograms/ml, respectively, were acquired after approximately 1.6 hours. Minimal inhibitory concentrations of < or = 6.25 micrograms/ml for in vitro sensitive bacteria were maintained for about 5 hours. Cephalexin from the tested preparations reached a mean area under the plasma concentration-time curve of 115.3 and 102.4 micrograms.h/ml, respectively. The plasma concentration decreased rapidly with a mean half life period of 1.4 hours in average. The other calculated pharmacokinetic parameters were also in the area of the data for dogs stated in the literature. There was no clear difference in the pharmacokinetics of both products, especially the bioavailability. Furthermore, both formulations were well tolerated clinically.

Analgesic effect of meloxicam in canine acute dermatitis--a pilot study

A double-blind trial was performed on 12 client-owned dogs suffering from acute and painful dermatitis. Clinically these cases represented pyotraumatic dermatitis and pyotraumatic folliculitis. Six dogs were injected with meloxicam and 6 were given placebo. Signs of pain were recorded on a visual analogue scale before administering the drug. This was repeated over the following 2-3 days. All dogs were treated with cephalexin orally. Six dogs given meloxicam and cephalexin showed an average decrease of pain on day 2 of 28.3%, whereas the 6 dogs given placebo and cephalexin showed an average decrease of pain on day 2 of 8.3%. When compared in the Wilcoxon two-sample test, using change in percent and absolute change, the 2 groups yielded p = 0.026 and p = 0.064 respectively. These findings indicate that meloxicam has an analgesic effect on acute dermatitis in dogs.

A bioassay evaluation of the urinary antibacterial efficacy of low dose prophylactic antibiotics in children with vesicoureteral reflux

PURPOSE

We evaluated by means of a bioassay the efficacy of 4 different antibiotics administered in a prophylactic dose to children with vesicoureteral reflux.

MATERIALS AND METHODS

A total of 159 urine samples from 53 children taking prophylactic antibiotics with proved vesicoureteral reflux were tested. The children were divided into 4 groups according to the antibiotic given, which included nalidixic acid, cephalexin, cotrimoxazole and cefixime. Urine samples were collected in the morning, at noon and in the evening, and each sample was bioassayed for growth inhibition of a standard Escherichia coli. The urine volume used was specifically determined for each antibiotic, and growth inhibition by this specific volume was equivalent to that produced by standard diffusion disks. In addition, the specific gravity, which reflected urinary concentration of each sample, was measured.

RESULTS

Mean patient age plus or minus standard deviation of the 4 groups was 53 +/- 41 for nalidixic acid, 23 +/- 34 for cephalexin, 55 +/- 35 for cotrimoxazole and 47 +/- 35 months for cefixime, respectively. In children less than 2 years old specific gravity was higher in the morning (1.021 +/- 0.0006 versus 1.0008 +/- 0.0004 at 8 a.m. and 2 p. m., respectively, p <0.05). In contrast, in children older than 4 years the specific gravity was higher in the afternoon and evening hours (1.019 +/- 0.003 versus 1.007 +/- 0.003 at 2 p.m. and 8 a.m., respectively, p <0.05). The percentage of patients who demonstrated growth inhibition in all 3 samples of the test day was 7%, 6%, 69% and 44% for nalidixic acid, cephalexin, cotrimoxazole and cefixime, respectively (p <0.001 for cotrimoxazole and cefixime versus nalidixic acid and cephalexin. Divided into morning, noon and evening, the percentage of samples that demonstrated growth inhibition was 85.7%, 21.4% and 7.1% for nalidixic acid, 37.5%, 12. 5% and 6.3% for cephalexin, 100%, 92.3% and 76.9% for cotrimoxazole and 100%, 77.7% and 55.5% for cefixime, respectively. A direct correlation was found between specific gravity and growth inhibition (r = 0.55, p <0.001).

CONCLUSIONS

Urine concentration during the day is dependent on age with older children having more concentrated urine in the latter part of the day. Growth inhibition is enhanced by concentrated urine. Compared to nalidixic acid and cephalexin, cotrimoxazole and cefixime produce a sustained bactericidal effect for about 60% of a 24-hour day due to the longer half-life.