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.

Effect of Cephalexin Plus Trimethoprim-Sulfamethoxazole vs Cephalexin Alone on Clinical Cure of Uncomplicated Cellulitis: A Randomized Clinical Trial

IMPORTANCE

Emergency department visits for skin infections in the United States have increased with the emergence of methicillin-resistant Staphylococcus aureus (MRSA). For cellulitis without purulent drainage, β-hemolytic streptococci are presumed to be the predominant pathogens. It is unknown if antimicrobial regimens possessing in vitro MRSA activity provide improved outcomes compared with treatments lacking MRSA activity.

OBJECTIVE

To determine whether cephalexin plus trimethoprim-sulfamethoxazole yields a higher clinical cure rate of uncomplicated cellulitis than cephalexin alone.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, double-blind, randomized superiority trial in 5 US emergency departments among outpatients older than 12 years with cellulitis and no wound, purulent drainage, or abscess enrolled from April 2009 through June 2012. All participants had soft tissue ultrasound performed at the time of enrollment to exclude abscess. Final follow-up was August 2012.

INTERVENTIONS

Cephalexin, 500 mg 4 times daily, plus trimethoprim-sulfamethoxazole, 320 mg/1600 mg twice daily, for 7 days (n = 248 participants) or cephalexin plus placebo for 7 days (n = 248 participants).

MAIN OUTCOMES AND MEASURES

The primary outcome determined a priori in the per-protocol group was clinical cure, defined as absence of these clinical failure criteria at follow-up visits: fever; increase in erythema (>25%), swelling, or tenderness (days 3-4); no decrease in erythema, swelling, or tenderness (days 8-10); and more than minimal erythema, swelling, or tenderness (days 14-21). A clinically significant difference was defined as greater than 10%.

RESULTS

Among 500 randomized participants, 496 (99%) were included in the modified intention-to-treat analysis and 411 (82.2%) in the per-protocol analysis (median age, 40 years [range, 15-78 years]; 58.4% male; 10.9% had diabetes). Median length and width of erythema were 13.0 cm and 10.0 cm. In the per-protocol population, clinical cure occurred in 182 (83.5%) of 218 participants in the cephalexin plus trimethoprim-sulfamethoxazole group vs 165 (85.5%) of 193 in the cephalexin group (difference, -2.0%; 95% CI, -9.7% to 5.7%; P = .50). In the modified intention-to-treat population, clinical cure occurred in 189 (76.2%) of 248 participants in the cephalexin plus trimethoprim-sulfamethoxazole group vs 171 (69.0%) of 248 in the cephalexin group (difference, 7.3%; 95% CI, -1.0% to 15.5%; P = .07). Between-group adverse event rates and secondary outcomes through 7 to 9 weeks, including overnight hospitalization, recurrent skin infections, and similar infection in household contacts, did not differ significantly.

CONCLUSIONS AND RELEVANCE

Among patients with uncomplicated cellulitis, the use of cephalexin plus trimethoprim-sulfamethoxazole compared to cephalexin alone did not result in higher rates of clinical resolution of cellulitis in the per-protocol analysis. However, because imprecision around the findings in the modified intention-to-treat analysis included a clinically important difference favoring cephalexin plus trimethoprim-sulfamethoxazole, further research may be needed.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00729937.

Safe use of selected cephalosporins in penicillin-allergic patients: A meta-analysis

Background

Recent analysis of clinical data and a clearer understanding of the role of chemical structure in the development of cross-reactivity indicate that the increased risk of an allergic reaction to a cephalosporin in penicillin-allergic patients is smaller than previously postulated.

Method

Medline and EMBASE databases were searched with the keywords: cephalosporin, penicillin, allergy, and crosssensitivity for the years 1960 through 2005. Among 219 articles retrieved, 9 served as source material for this evidence-based meta-analysis.

Results

A significant increase in allergic reactions to cephalothin (odds ratio [OR] = 2.5; 95% confidence interval [CI] = 1.1 to 5.5), cephaloridine (OR = 8.7; CI = 5.9 to 12.8), and cephalexin (OR = 5.8; CI = 3.6 to 9.2), and all first generation cephalosporins plus cefamandole (OR = 4.8; CI = 3.7 to 6.2) were observed in penicillin allergic patients; no increase was observed with second generation cephalosporins (OR = 1.1; CI, 0.6 to 2.1) or third generation cephalosporins (OR = 0.5; CI = 0.2 to 1.1). Clinical challenges, skin testing, and monoclonal antibody studies point to the paramount importance of similarities in side chain structure to predict cross-allergy between cephalosporins and penicillins.

Conclusion

First-generation cephalosporins have cross-allergy with penicillins, but cross-allergy is negligible with second-and third-generation cephalosporins. Particular emphasis should be placed on the role of chemical structure in determining the risk of cross-reactivity between specific agents. 2007 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Prophylactic antibiotic administration induced bronchospasm as increased airway pressure during general anesthesia

BACKGROUND

Anaphylactic reaction induced bronchospasm as wheezing and severe elevation of airway pressure was observed in a succession of patients during general anesthesia at our institute in November 2007. The aim of this survey was to investigate the suspected causes and risk factors of these anaphylactic reactions and the degree of correlation.

METHODS

All patients who received general anesthesia between November 1 and November 10, 2007 were enrolled. Underlying diseases, substances including intravenous and inhalational anesthetics, antibiotics, and the degree of increase in airway pressure were recorded. Enrolled patients were divided into a significant-airway-pressure-elevation group (Group P) and a no-airway-pressure-elevation group (Group N).

RESULTS

A new brand of cephalexin (Roles) used as a prophylactic antibiotic was identified as the most likely causative substance of this succession of suspected anaphylactic reactions (28 in 185 patients, 15.14%), and rapid administration was a contributor to these anaphylactic reactions.

CONCLUSION

In this study, we found that rapid administration of Roles was the main cause of suspected anaphylactic reaction presenting as bronchospasm with severe elevated airway pressure. Using Roles as the prophylactic antibiotic is not recommended in patients receiving general anesthesia.

Teratogenicity of antibacterial agents

The aim of our study was to study the possible correlation between use of antibacterial drugs in pregnancy and occurrence of congenital malformations. Among 6099 investigated pregnant women, 392 (6.43%) used antibacterial drugs. The most frequently used antibacterials belonged to category B (75.77%), while 14.54% antibiotics belonged to category D and 1.02% to category X. The most often used antibiotics were cephalexin (22.19%), amoxicillin (20.66%) and ampicillin (14.29%). In 14 embryos exposed to effects of beta-lactams in utero, malformations were detected. The results of this study show possible teratogenic potential even with those antibacterials which are considered safe, but as those are usually minor malformations, they often pass undetected. Because of that and because of frequent use of antibacterials during pregnancy, detailed examinations concerning their safety should be made.

Cefdinir vs. cephalexin for mild to moderate uncomplicated skin and skin structure infections in adolescents and adults

OBJECTIVES

To compare the efficacy and safety of cefdinir to that of cephalexin in adolescents and adults with mild to moderate uncomplicated skin and skin structure infections (USSSI).

RESEARCH DESIGN AND METHODS

This was an investigator-blinded, multicenter study in which patients at least 13 years of age with USSSI were randomized to receive 10 days of cefdinir 300 mg twice daily (BID) or cephalexin 250 mg four times daily (QID). Patients were evaluated at baseline, by telephone on Days 3-5, and during office visits on Days 12-14 (end-of-therapy [EOT] visit) and Days 17-24 (test-of-cure [TOC] visit).

MAIN OUTCOME MEASURES

Clinical response was evaluated at the TOC visit. Patient reported outcomes, including a usefulness questionnaire, were also assessed.

RESULTS

Three hundred and ninety-one patients were treated. The treatment groups were well matched with regard to demographic characteristics and types of infection. Abscess(es) (26%), wound infection (24%), and cellulitis (21%) were the most common infections. At the TOC visit, the clinical cure rate for both treatment groups was 89% (151/170 for cefdinir and 154/174 for cephalexin) in clinically evaluable patients (95% CI for difference in cure rates [-6.7 to 7.3]). In the intent-to-treat analysis, cure rates were 83% for cefdinir vs. 82% for cephalexin. Clinical cure rates for infections caused by methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus were 93% (37/40) and 92% (35/38) for cefdinir vs. 91% (29/32) and 90% (37/41) for cephalexin (p > 0.999 comparing treatment groups for MSSA; p > 0.999 for MRSA). The usefulness questionnaire demonstrated that cefdinir was more highly rated in the mean composite score (87.4 vs. 83.6, p = 0.04), with the difference primarily due to the respondents' preference for the convenience of taking the study medication (mean score 93.5 vs. 74.1 for cephalexin, p < 0.001). The study had the following limitations: the requirement for culture at baseline likely skewed the enrollment of patients towards those with abscesses; the results of culture in patients with USSSIs are often nonspecific; in some patients entering the study with a diagnosis of cellulitis, the cellulitis was associated with an abscess; and, incision and drainage (I&D), spontaneous drainage, and needle aspiration are likely to have contributed to clinical response for purulent infections, and in particular MRSA-associated infections. Both study drugs were well tolerated. The most common treatment-related adverse events were diarrhea (10% cefdinir, 4% cephalexin, p = 0.017), nausea (3% and 6%, respectively, p = 0.203), and vaginal mycosis (3% and 6% of females, respectively, p = 0.500).

CONCLUSIONS

This study demonstrated that empiric coverage of USSSIs with cephalosporin therapy remains an appropriate clinical strategy. MRSA infections responded well in both arms of the study, suggesting that the choice of a cephalosporin did not adversely affect patient outcome. However, cephalosporins do not have accepted, clinically relevant in vitro activity against MRSA. Hence, the clinical response rates seen in this study against MRSA infections must be interpreted with caution. Cefdinir was more highly rated than cephalexin in a composite usefulness assessment.

Delirium in an adolescent patient during treatment with cephalexin

Although cephalosporins are generally safe, they have been reported to cause neurotoxic effects in some subjects. We report on a 16-year-old boy with no previous history of psychiatric illness, who developed symptoms of delirium during treatment of paronychia infection with cephalexin. Possible reasons for our patient's particular vulnerability to adverse drug effects in the central nervous system include his young age, a developmental delay, and an earlier head injury.

Fatal cephalosporin-induced acute hypersensitivity myocarditis

A frequently fatal, although rare, side effect of cephalosporin antibiotics is noninfectious myocarditis. We report two cases of hypersensitivity myocarditis secondary to administration of cephalosporin antibiotics. In both cases, acute hypersensitivity myocarditis was not suspected clinically, and the diagnosis was made postmortem. Histology revealed intense eosinophilic infiltration of the endomyocardium with eosinophil degranulation and myocyte damage, Clinically, death in both cases was due to cardiac failure. When suspected early, appropriate management may be lifesaving.

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.

Bullous pemphigoid in a patient with psoriasis and possible drug reaction: a case report

Bullous pemphigoid, first described in 1953 by Lever, is the most common autoimmune blistering skin disease. As such,this disorder may be encountered relatively frequently in the dermatologist's office, though it is a rarity on the inpatient medicine wards. Lesions develop when autoantibodies are directed against glycoproteins BPAG1 and BPAG2, hemidesmosomes that are embedded in the epidermal basement membrane. The immune complex triggers a complement cascade that activates neutrophils and eosinophils, resulting in the release of proteolytic enzymes. As a result, subepidermal bullae develop; the diagnosis is confirmed by histological examination of skin biopsy. The case of bullous pemphigoid described here presented the treating team with some diagnostic challenges because of the patient's concomitant history of psoriasis and apparent dermatologic reaction to cephalexin. Though the patient's skin lesions resolved rapidly with appropriate treatment, the case generated many questions about the diagnosis and most effective management of bullous pemphigoid.

Cephalexin-Induced Acute Tubular Necrosis

A 24-year-old woman with a history of penicillin allergy developed reversible acute renal failure after receiving cephalexin for 4 days. The patient experienced nausea, vomiting, diarrhea, pruritus, cough, and an elevated creatinine level of 2.2 mg/dl. The patient's creatinine level continued to rise, peaking at 5.3 mg/dl on hospital day 3. Nephrotoxic acute tubular necrosis was confirmed by electron microscopy. Within 1 month of discharge from the hospital, the patient's creatinine level decreased to 0.6 mg/dl. Although the renal injury most commonly associated with the cephalosporin class of antibiotics is allergic interstitial nephritis, currently available cephalosporins infrequently can cause direct tubular toxicity.

Thrombotic thrombocytopenic purpura after cephalosporin administration: a possible relationship

BACKGROUND

Acquired thrombotic thrombocytopenic purpura (TTP) is an autoimmune disorder. The pathogenesis is believed to be mediated by an autoantibody directed against the metalloproteinase responsible for the degradation of the very-high-molecular-weight multimers of the vWF. The syndrome can be precipitated by a variety of conditions, and certain medications also have been implicated.

CASE REPORTS

The cases of two patients who took a cephalosporin antibiotic, cephalexin (Keflex, Eli Lilly), and then developed TTP are reported. One patient subsequently received a third-generation cephalosporin, ceftriaxone (Rocephin, Roche), without adverse reaction. Of interest, one patient had taken cefaclor (Ceclor, Eli Lilly) 8 years before and had also developed TTP at that time. The other patient also took cefaclor for approximately 3 weeks before taking cephalexin. In addition, she had had a dose of clarithromycin (Biaxin, Abbott Laboratories) the day before the onset of the TTP symptoms.

CONCLUSIONS

To our knowledge, TTP has not been reported previously after administration of cephalosporin antibiotics. Attention is called to the possibility that this syndrome may occur after exposure to some of these drugs, although the incidence is very rare or, alternatively, underdiagnosed.

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).

Generalized pustules in a healthy woman

A healthy 47-year-old woman developed diffuse pustules and edema of the skin after exposure to diltiazem and cephalexin. Bacterial, fungal and viral cultures were sterile suggesting a noninfectious etiology. A skin biopsy showed spongiosis, subcorneal collections of neutrophils, papillary dermal edema and a superficial perivascular mixed cell infiltrate. The clinical and histopathologic findings were consistent with acute generalized exanthematous pustulosis (AGEP). The patient was treated with supportive care and the pustular dermatitis cleared. AGEP is a rare complication of drug therapy and should be considered in the differential diagnosis of patients presenting with acute onset pustular dermatitis. Drug reactions are an uncommon and unpredictable complication of medical therapy. Cutaneous drug reaction rates occur with a frequency of 1% to 8% and can be higher for certain classes of drugs. They can range from mild morbilliform eruptions to more severe forms such as drug-hypersensitivity syndrome, toxic epidermal necrolysis or anaphylaxis. Acute generalized exanthermatous pustulosis (AGEP) is a rare presentation of a drug reaction and can be difficult to distinguish from other pustular dermatoses. Herein we review a case of AGEP and include a discussion of salient clinical and histological features of AGEP.

A comparison of the efficacy and safety of mupirocin cream and cephalexin in the treatment of secondarily infected eczema

The efficacy and safety of mupirocin calcium cream were compared with those of oral cephalexin in the treatment of secondarily infected eczema. In this multicentre, double-blind, double-dummy study, 159 patients with secondarily infected eczema (suitable for treatment with topical antimicrobials) and a total skin infection rating scale score of 8 or more were randomized to receive either topical mupirocin cream three times daily or oral cephalexin, 250 mg four times daily, for 10 days (intent-to-treat group). Clinical success (per-protocol group), defined in part as a patient with a response of improvement in the skin infection rating scale, was similar in the two groups: 89% for mupirocin (n = 44) and 82% for cephalexin (n = 38) [P = 0.29; 95% confidence interval (-8.4%, 22.5%)]. Bacteriological success (intent-to-treat group), defined as a patient with a response of eradication, improvement or colonization of bacteria at the end of therapy, however, was significantly higher for mupirocin [50% and 28% in the mupirocin (n = 48) and cephalexin (n = 47) groups, respectively; P=0.005]. Mupirocin cream was as well tolerated as cephalexin; 9% and 13% of patients reported adverse events related or possibly related to study medication in the mupirocin and cephalexin groups, respectively. The most common adverse events overall were diarrhoea and nausea. Mupirocin cream applied three times daily is as effective clinically and superior bacteriologically compared with oral cephalexin given four times daily in the treatment of secondarily infected eczema of limited depth and severity. Mupirocin cream is as well tolerated as oral cephalexin, and more patients prefer the topical regimen, which should improve patient compliance.

Equal allergenic potency of beta-lactam antibiotics produced by chemical or enzymatic manufacturing--mouse IgE test

BACKGROUND

Cephalexin and amoxicillin are semisynthetic beta-lactam antibiotics with a broad spectrum of antibacterial activity against gram-positive and gram-negative microorganisms. Both antibiotics are produced by a new 'green' process in which enzyme technology is used to combine the intermediate structure and the side chain in an aqueous medium to yield cephalexin or amoxicillin, thus avoiding the use of several chemical reagents and volatile organic solvents. As a result of the enzyme technology a new residual protein impurity has been identified. To check for the sensitizing capacity of the residual protein, a mouse IgE test was used to detect differences in the production of specific IgE by chemical or enzymatic preparations of the antibiotics.

METHODS

Balb/c female mice were immunized intraperitoneally with alum and conjugates of different amoxicillins or cephalexins with ovalbumin (OVA). After 16 days, the amoxicillin mice were injected with one half the original amount of antigen. After 19-23 days, the sera were tested for specific IgE by the passive cutaneous anaphylaxis assay in Sprague-Dawley rats. The greatest dilution of sera which resulted in a positive response was the titer of specific IgE.

RESULTS

No significant differences were found between the titers of specific IgE caused by the chemically and enzymatically produced beta-lactam antibiotics, indicating that the antibiotics are equal in allergenicity.

CONCLUSIONS

The data show that a residual level of 35 ppm protein did not affect the allergenic potency of these beta-lactam antibiotics as determined by the mouse allergenicity model.

Bullous pemphigoid induced by cephalexin

Two young men developed severe bullous eruptions with a distinctive clinical picture of severe flexural involvement and extensive mucosal ulceration. Biopsies showed subepidermal bullae and associated inflammation consisted of predominantly neutrophils. Both had IgG and C3 staining of the dermal-epidermal junction on direct immunofluorescence. Bullous pemphigoid was diagnosed on the basis of clinical, histopathological and immunofluorescence findings. Both cases occurred after recent ingestion of cephalexin. We believe they represent the first reported cases of bullous pemphigoid induced by cephalexin.

Comparison of pivmecillinam and cephalexin in acute uncomplicated urinary tract infection

The clinical and bacteriological efficacy of a 3-day course of pivmecillinam, 200 mg three times daily, was compared with that of a 7-day course of cephalexin, 250 mg four times daily, in 216 patients with a bacteriologically confirmed, acute, uncomplicated, urinary tract infection. Both treatments were similarly effective. Clinical cure or improvement was obtained in 95.3% of patients given pivmecillinam and in 93.6% of patients given cephalexin. Bacteriological success was achieved in 89.7 and 81.7% patients taking pivmecillinam or cephalexin, respectively. Eradication rates for Escherichia coli were 90.1% for pivmecillinam and 80.6% for cephalexin. Both treatments were well tolerated. This study has confirmed that a 3-day course of pivmecillinam is effective and well tolerated in uncomplicated cystitis.

Cefdinir versus cephalexin for the treatment of skin and skin-structure infections. The Cefdinir Adult Skin Infection Study Group

Because of increasing resistance to older antimicrobial agents, newer drugs need to be evaluated for the treatment of skin and skin-structure infections (SSSIs). This double-masked, randomized, comparative, multicenter study enrolled patients aged 13 years or older with SSSIs to receive either cefdinir 300 mg BID or cephalexin 500 mg QID for 10 days. Nine hundred fifty-two patients (474 in the cefdinir group and 478 in the cephalexin group) took part, primarily white males between 18 and 65 years of age. There were two follow-up visits, with efficacy determined at the test-of-cure visit, 7 to 16 days posttherapy. Many patients were not microbiologically assessable, primarily because of negative cultures at study admission. Patients who required surgical intervention (e.g., incision and drainage) at the site of infection more than 24 hours after the initiation of drug therapy were defined as treatment failures. Significantly more isolated pathogens were resistant to cephalexin than to cefdinir. In the 178 efficacy-assessable cefdinir-treated patients, the rate of pathogen eradication was 93% (200/215), and the rate of successful clinical response was 88% (157/178), compared with 89% (221/247) and 87% (177/204), respectively, in the 204 efficacy-assessable cephalexin-treated patients. Using confidence-interval analysis, the microbiologic and clinical response rates of the cefdinir-treated patients were statistically equivalent to those of the cephalexin-treated patients. At the follow-up visits, patients were questioned about any adverse events occurring since their previous visit. Any untoward symptom occurring during or within 2 days after completion of drug treatment was considered an adverse reaction if the investigator judged it to be definitely, probably, or possibly related to the study drug. One hundred twenty-three (26%) cefdinir-treated patients and 77 (16%) cephalexin-treated patients experienced at least one adverse reaction, a statistically significant difference. Study drug was discontinued for adverse reactions in 20 (4%) cefdinir-treated patients and 13 (3%) cephalexin-treated patients; in the two groups, 10 and 7 patients, respectively, were discontinued for diarrhea. Cefdinir taken BID was as effective as cephalexin taken QID in the treatment of mild-to-moderate SSSIs and was well tolerated by most patients. The increased antibacterial activity of cefdinir must be balanced against the higher rate of diarrhea seen in patients treated with this drug.

Clostridium difficile infection in obstetric and gynecologic patients

We reviewed hospital records of women on the obstetrics and gynecologic services with a diagnosis of antibiotic-associated diarrhea, pseudomembranous colitis, or Clostridium difficile infection to better characterize the incidence and course of women with C difficile infection. Cases were included if there was identification of C difficile by culture or toxin or endoscopic verification of pseudomembranous colitis. Between January 1985 and June 1995, there were 74,120 admissions to the obstetrics and gynecology services at two tertiary level hospitals. Eighteen women were found to have documented C difficile infection (0.02%)--3 from the obstetric services, 10 from the benign gynecologic services, and 5 from the gynecologic/oncology services. Diarrhea developed from 2 days to 30 days after antibiotics had been given (mean, 10 days). Nine patients had fever, six had nausea and vomiting, and five had abdominal pain. Antimicrobial agents given before infection included cephalexin, cefoxitin, imipenem, ciprofloxacin, trimethoprim/sulfamethoxazole, ampicillin, gentamicin, and clindamycin. All patients were treated successfully with inpatient antimicrobial agents-15 with metronidazole and 3 with vancomycin. There was one possible recurrence.

Cephalexin rash in infectious mononucleosis

The ampicillin rash occurring in cases of infectious mononucleosis is well documented. Similar phenomena have also been observed with other antibiotics. The case of a patient with infectious mononucleosis treated with cephalexin who later showed a rash is presented and the previous literature is reviewed. The rash seen in this patient, who was treated with cephalexin, may be similar to the rash seen with ampicillin treatment of patients with infectious mononucleosis. The mechanism by which these eruptions occur is not completely understood, although there are many interesting theories. Perhaps rashes during infectious mononucleosis in association with other antibiotics are actually more common, but just not recognized. A heightened awareness of this possibility may therefore lead to recognition of more cases and further understanding of this entity.

Study of use of cefdinir versus cephalexin for treatment of skin infections in pediatric patients. The Cefdinir Pediatric Skin Infection Study Group

Three hundred ninety-four patients, aged 6 months to 12 years, entered a multicenter, randomized, controlled, investigator-blind study comparing cefdinir, 7 mg/kg of body weight twice a day, with cephalexin, 10 mg/kg four times a day, each given for 10 days. The most common infections treated were impetigo and secondary infection of preexisting dermatitis. The most common pathogens isolated were Staphylococcus aureus and Streptococcus pyogenes. Two hundred thirty-one patients were microbiologically evaluable. Microbiologic eradication rates were 164 of 165 pathogens (99.4%) in the cefdinir group and 152 of 156 pathogens (97.4%) in the cephalexin group (P = 0.14). Clinical cure rates were 116 of 118 patients (98.3%) in the cefdinir group and 106 of 113 patients (93.8%) in the cephalexin group (P = 0.056). Sixteen percent of cefdinir patients and 11% of cephalexin patients experienced adverse events (P = 0.11), the most common being diarrhea, which affected 8% of the cefdinir group and 4% of the cephalexin group. Cefdinir appears to be an effective and well-tolerated agent for the treatment of uncomplicated skin and skin structure infections in pediatric patients.

A large population-based follow-up study of trimethoprim-sulfamethoxazole, trimethoprim, and cephalexin for uncommon serious drug toxicity

We conducted a population-based 45-day follow-up study of 232,390 people who were prescribed trimethoprim-sulfamethoxazole (TMP-SMZ), 266,951 prescribed trimethoprim alone, and 196,397 prescribed cephalexin, to estimate the risk of serious liver, blood, skin, and renal disorders resulting in referral or hospitalization associated with these drugs. The results were based on information recorded on office computers by selected general practitioners in the United Kingdom, together with a review of clinical records. The risk of clinically important idiopathic liver disease was similar for persons prescribed TMP-SMZ (5.2/100,000) and those prescribed trimethoprim alone (3.8/100,000). The risk for those prescribed cephalexin was somewhat lower (2.0/100,000). Only five patients experienced blood disorders, one of whom was exposed to TMP-SMZ; of seven with erythema multiforme and Stevens-Johnson syndrome, four were exposed to TMP-SMZ. The one case of toxic epidermal necrolysis occurred in a patient who took cephalexin. Finally, only five cases of acute parenchymal renal disease occurred, none likely to be caused by a study drug. We conclude that the risk of the serious diseases studied is small for the three agents, and compares reasonably with the risk for many other antibiotics.

Serum sickness-like reactions to cefaclor: role of hepatic metabolism and individual susceptibility

In an effort to explain the increased incidence of serum sickness-like reactions (SSLR) in patients receiving cefaclor, we used an in vitro murine microsomal system as a surrogate for in vivo hepatic drug biotransformation. Lymphocytes from three groups of subjects were exposed to a nonselective mixture of cefaclor metabolites. After an 18-hour incubation of lymphocytes with these metabolites, cells were examined for viability by trypan blue exclusion. The subject groups consisted of patients with a previous history of SSLR after cefaclor therapy (n = 19), patients who experienced adverse reactions to cefaclor suggestive of immediate hypersensitivity (n = 11), and control subjects who had previously tolerated at least two courses of cefaclor therapy without adverse effect (n = 9). Additionally, immediate family members of six subjects with cefaclor-associated SSLR were studied. Lymphocyte killing was 100% greater than baseline (i.e., a non-drug-containing control) in subjects with SSLR compared with those with immediate hypersensitivity reactions (4% cell death above baseline; p < 0.001) and nonaffected control subjects (6% cell death above baseline; p < 0.001). Family studies were consistent with a pattern of maternal inheritance; five of six mothers who had not received cefaclor had a positive (i.e., > or = 35% cell death above baseline) in vitro cytotoxic response. Other studies confirmed the requirement for biotransformation of the parent drug to elicit cell death, demonstrated specificity of the reaction to cefaclor, illustrated a lack of cross-reactivity to cephalexin in subjects with SSLR to cefaclor, and verified the reproducibility of the reaction over time in an affected subject. Our findings indicate that cefaclor associated SSLR may be a unique adverse drug reaction that requires biotransformation of the parent drug and may result from inherited defects in the metabolism of reactive intermediates. Furthermore, this condition can be retrospectively confirmed with an in vitro lymphocyte-based cytotoxicity assay.

Pustular eruption after drug exposure: is it pustular psoriasis or a pustular drug eruption?

Generalized pustular eruptions with fever present a diagnostic challenge. A history of preceding drug exposure, and rapid disappearance of the eruption after the drug is stopped, suggest a drug-induced aetiology rather than pustular psoriasis. We describe and evaluate the clinical and histological features of four patients who developed a generalized pustular eruption following drug administration. The history of preceding drug exposure and the presence of a variable number of eosinophils in the inflammatory infiltrate in the lesions of these cases suggested that the generalized pustular eruptions were drug-induced.

Comparative evaluation of cefadroxil and cephalexin in children and adolescents with pyodermas. Cefadroxil Once Daily Pyoderma Study Group

This randomized, multicenter study compared the safety and efficacy of cefadroxil with that of cephalexin for the treatment of pyodermas in children and adolescents (1-18 years of age). Cefadroxil was given as a single oral daily dose of 30 mg/kg, and cephalexin 30 mg/kg/day was given in two divided doses. The maximum daily dose for both drugs was 1 gm, and treatment was administered for 10 days. Clinical and bacteriologic evaluations were made on days 4 or 5 during therapy and 2 to 4 days after therapy was completed. Of the 462 patients enrolled in the study, 156 patients in the cefadroxil group and 133 patients in the cephalexin group were evaluable. Staphylococcus aureus (56% of isolates) and Streptococcus pyogenes (39% of isolates) were isolated most frequently. The bacteriologic response was statistically greater in the patients treated with cefadroxil than in those treated with cephalexin (96% versus 89%; P = 0.042). A satisfactory clinical response was reported in 147 (94%) cefadroxil-treated patients and 122 (92%) cephalexin-treated patients (P = 0.476). The overall effective response to treatment was significantly higher with cefadroxil than with cephalexin (94% versus 86%; P = 0.024). Compliance with 9 or 10 days of therapy was similar in both treatment groups, although there was a difference between the two treatment groups with respect to completion of medication regimen: 95% of patients taking cefadroxil once daily--versus 65% of patients taking cephalexin twice daily--took 100% of their medication (P < 0.0001). Adverse events were infrequent and mild. The results of this study demonstrate that once-daily cefadroxil offers greater bacteriologic eradication and a better overall effective response than twice-daily cephalexin for the treatment of pyodermas caused by gram-positive pathogens in children and adolescents.

Cephalexin-induced Stevens-Johnson syndrome

OBJECTIVE

To report a case of cephalexin-induced Stevens-Johnson syndrome (SJS), a devastating adverse drug reaction that involves the entire skin surface and mucosal areas of the body.

DATA SOURCES

MEDLINE search (key terms cephalosporins, Stevens-Johnson syndrome, erythema multiforme, and systemic lupus erythematosus) and references identified from bibliographies of pertinent articles.

DATA SYNTHESIS

Clinical presentation and manifestations of SJS include the skin, eyes, gastrointestinal tract, and pulmonary system. Infectious complications are the leading cause of mortality. Early intervention is important to prevent progression of SJS. The case described is consistent with the features of this syndrome. The patient presented with fever, arthralgias, and malaise. Skin lesions included a diffuse violet macular rash with erythema and multiple bullous lesions on her neck and abdomen. The skin biopsy was consistent with SJS. Multiple mucocutaneous ulcers were found in her mouth, but no evidence of lower gastrointestinal tract involvement was documented. She remained relatively free of pulmonary complaints except for the presenting bronchitis.

CONCLUSIONS

Cephalexin should be added to the list of agents to consider as iatrogenic causes of SJS.

Serum sickness-like reactions to cefaclor

In this study, we evaluated whether the high number of reports of serum sickness to cefaclor was present in every country and year, and whether these figures from voluntary reporting facilitated an estimation of the relative risk. A nested case-control study was performed with reports of all suspected adverse reactions (ADR) to cefaclor, amoxicillin and cephalexin in the period 1968-1987, as reported to the WHO Collaborating Center for International Drug Monitoring from the U.S.A., the U.K., Sweden, Canada and Germany. The ADR-reporting odds ratio was defined as the ratio of the odds of the number of ADR-reports of serum sickness to cefaclor and amoxicillin or cephalexin and the odds of similar reports of non-serum sickness to cefaclor and amoxicillin or cephalexin. The ADR-reporting odds ratio adjusted for country, age, gender, origin of the report and year of marketing was 12.4 for cefaclor vs amoxicillin and 18.5 for cefaclor vs cephalexin. In children (< 15 years of age) and in adults (> 15 years of age), the relative risk of developing serum sickness of cefaclor vs amoxicillin was estimated at 13.9 (95% confidence interval (95% CI): 6.0-32.2) and 2.9 (95% CI: 0.9-9.4) respectively in the U.S.A., and at 15.1 (95% CI: 7.2-31.5) and 5.5 (95% CI: 2.0-15.0) respectively in the other four countries together. In this study, the ADR-reporting odds ratio facilitated a valid estimation of the relative risk.

Ofloxacin versus cephalexin for treating skin and soft tissue infections

Patients with acute localized skin or soft tissue infections were randomized to receive either ofloxacin (300 mg orally, b.i.d.) or cephalexin (500 mg orally, b.i.d.). Among 401 enrolled patients, 382 were evaluable for safety and 148 for microbiologic response. Microbiologic cure occurred in 93.4% of ofloxacin-treated patients and in 94.0% of those treated with cephalexin. Clinical cure or improvement, respectively, was found in 85.2% and 11.1% of patients treated with ofloxacin, and 83.6% and 14.9% of patients receiving cephalexin. Adverse effects (primarily associated with the gastrointestinal tract and central nervous system) were considered to be drug-related in 7.9% of those receiving ofloxacin and 4.8% of those receiving cephalexin. Thus, ofloxacin is as effective and well tolerated as cephalexin and a good alternate antibiotic for treating skin and skin structure infections caused by a variety of pathogens.