Gastrointestinal side effects of clindamycin and ampicillin therapy

Economic Viability of Penicillin Allergy Testing to Avoid Improper Clindamycin Surgical Prophylaxis

OBJECTIVE

Patients mislabeled with a penicillin allergy are often unnecessarily given prophylactic clindamycin. Thus, otolaryngologists may cause harm due to clindamycin's associated risk of Clostridioides difficile infections (CDI) and surgical site infections (SSI). The objective of this study was to determine the economic feasibility of penicillin allergy testing in preventing unnecessary clindamycin use among patients with an unconfirmed penicillin allergy prior to otolaryngologic surgery.

METHODS

A break-even analysis was performed using the average cost of penicillin allergy testing and a CDI/SSI to calculate the absolute risk reduction (ARR) in baseline CDI/SSI rate due to clindamycin required for penicillin testing to be economically sustainable. The binomial distribution was used to calculate the probability that current penicillin testing can achieve this study's ARR.

RESULTS

Preoperative penicillin testing was found to be economically sustainable if it could decrease the baseline CDI rate by an ARR of 1.06% or decrease the baseline SSI rate by an ARR of 1.34%. The probability of penicillin testing achieving these ARRs depended on the baseline CDI and SSI rates. When the CDI rate was at least 5% or the SSI rate was at least 7%, penicillin allergy testing was guaranteed to achieve economic sustainability.

CONCLUSION

In patients mislabeled with a penicillin allergy, preoperative penicillin allergy testing may be an economically sustainable option to prevent the unnecessary use of prophylactic clindamycin during otolaryngologic surgery. Current practice guidelines should be modified to recommend penicillin allergy testing in patients with an unconfirmed allergy prior to surgery.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2022.

Oral antibiotic prescribing by NHS dentists in England 2010-2017

Introduction Dentists prescribe a significant proportion of all antibiotics, while antimicrobial stewardship aims to minimise antibiotic-prescribing to reduce the risk of developing antibiotic-resistance and adverse drug reactions.Aims To evaluate NHS antibiotic-prescribing practices of dentists in England between 2010-2017.Methods NHS Digital 2010-2017 data for England were analysed to quantify dental and general primary-care oral antibiotic prescribing.Results Dental prescribing accounted for 10.8% of all oral antibiotic prescribing, 18.4% of amoxicillin and 57.0% of metronidazole prescribing in primary care. Amoxicillin accounted for 64.8% of all oral antibiotic prescribing by dentists, followed by metronidazole (28.0%), erythromycin (4.4%), phenoxymethylpenicillin (0.9%), clindamycin (0.6%), co-amoxiclav (0.5%), cephalosporins (0.4%) and tetracyclines (0.3%). Prescriptions by dentists declined during the study period for all antibiotics except for co-amoxiclav. This increase is of concern given the need to restrict co-amoxiclav use to infections where there is no alternative. Dental prescribing of clindamycin, which accounted for 43.9% of primary care prescribing in 2010, accounted for only 14.6% in 2017. Overall oral antibiotic prescribing by dentists fell 24.4% as compared to 14.8% in all of primary care.Conclusions These data suggest dentists have reduced antibiotic prescribing, possibly more than in other areas of primary-care. Nonetheless, opportunities remain for further reduction.

Commensal-derived metabolites govern Vibrio cholerae pathogenesis in host intestine

BACKGROUND

Recent evidence suggests that the commensal microbes act as a barrier against invading pathogens and enteric infections are the consequences of multi-layered interactions among commensals, pathogens, and the host intestinal tissue. However, it remains unclear how perturbations of the gut microbiota compromise host infection resistance, especially through changes at species and metabolite levels.

RESULTS

Here, we illustrate how Bacteroides vulgatus, a dominant species of the Bacteroidetes phylum in mouse intestine, suppresses infection by Vibrio cholerae, an important human pathogen. Clindamycin (CL) is an antibiotic that selectively kills anaerobic bacteria, and accordingly Bacteroidetes are completely eradicated from CL-treated mouse intestines. The Bacteroidetes-depleted adult mice developed severe cholera-like symptoms, when infected with V. cholerae. Germ-free mice mono-associated with B. vulgatus became resistant to V. cholerae infection. Levels of V. cholerae growth-inhibitory metabolites including short-chain fatty acids plummeted upon CL treatment, while levels of compounds that enhance V. cholerae proliferation were elevated. Furthermore, the intestinal colonization process of V. cholerae was well-simulated in CL-treated adult mice.

CONCLUSIONS

Overall, we provide insights into how a symbiotic microbe and a pathogenic intruder interact inside host intestine. We identified B. vulgatus as an indigenous microbial species that can suppress intestinal infection. Our results also demonstrate that commensal-derived metabolites are a critical determinant for host resistance against V. cholerae infection, and that CL pretreatment of adult mice generates a simple yet useful model of cholera infection.

Evaluation of treatment options for methicillin-resistant Staphylococcus aureus infections in the obese patient

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major cause of infection in both the hospital and community setting. Obesity is a risk factor for infection, and the prevalence of this disease has reached epidemic proportions worldwide. Treatment of infections in this special population is a challenge given the lack of data on the optimal antibiotic choice and dosing strategies, particularly for treatment of MRSA infections. Obesity is associated with various physiological changes that may lead to altered pharmacokinetic parameters. These changes include altered drug biodistribution, elimination, and absorption. This review provides clinicians with a summary of the literature pertaining to the pharmacokinetic and pharmacodynamic considerations when selecting antibiotic therapy for the treatment of MRSA infections in obese patients.

Incidence and nature of adverse reactions to antibiotics used as endocarditis prophylaxis

OBJECTIVES

Antibiotic prophylaxis (AP) administration prior to invasive dental procedures has been a leading focus of infective endocarditis prevention. However, there have been long-standing concerns about the risk of adverse drug reactions as a result of this practice. The objective of this study was to identify the incidence and nature of adverse reactions to amoxicillin and clindamycin prophylaxis to prevent infective endocarditis.

METHODS

We obtained AP prescribing data for England from January 2004 to March 2014 from the NHS Business Services Authority, and adverse drug reaction data from the Medicines and Healthcare Products Regulatory Agency's Yellow Card reporting scheme for prescriptions of the standard AP protocol of a single 3 g oral dose of amoxicillin or a single 600 mg oral dose of clindamycin for those allergic to penicillin.

RESULTS

The reported adverse drug reaction rate for amoxicillin AP was 0 fatal reactions/million prescriptions (in fact 0 fatal reactions for nearly 3 million prescriptions) and 22.62 non-fatal reactions/million prescriptions. For clindamycin, it was 13 fatal and 149 non-fatal reactions/million prescriptions. Most clindamycin adverse drug reactions were Clostridium difficile infections.

CONCLUSIONS

AP adverse drug reaction reporting rates in England were low, particularly for amoxicillin, and lower than previous estimates. This suggests that amoxicillin AP is comparatively safe for patients without a history of amoxicillin allergy. The use of clindamycin AP was, however, associated with significant rates of fatal and non-fatal adverse drug reactions associated with C. difficile infections. These were higher than expected and similar to those for other doses, durations and routes of clindamycin administration.

Cefoperazone-treated mice as an experimental platform to assess differential virulence of Clostridium difficile strains

The toxin-producing bacterium C. difficile is the leading cause of antibiotic-associated colitis, with an estimated 500,000 cases C. difficile infection (CDI) each year in the US with a cost approaching 3 billion dollars. Despite the significance of CDI, the pathogenesis of this infection is still being defined. The recent development of tractable murine models of CDI will help define the determinants of C. difficile pathogenesis in vivo. To determine if cefoperazone-treated mice could be utilized to reveal differential pathogenicity of C. difficile strains, 5-8 week old C57BL/6 mice were pretreated with a 10 d course of cefoperazone administered in the drinking water. Following a 2-d recovery period without antibiotics, the animals were orally challenged with C. difficile strains chosen to represent the potential range of virulence of this organism from rapidly fatal to nonpathogenic. Animals were monitored for loss of weight and clinical signs of colitis. At the time of harvest, C. difficile strains were isolated from cecal contents and the severity of colitis was determined by histopathologic examination of the cecum and colon. Cefoperazone treated mice challenged with C. difficile strains VPI 10463 and BI1 exhibited signs of severe colitis while infection with 630 and F200 was subclinical. This increased clinical severity was correlated with more severe histopathology with significantly more edema, inflammation and epithelial damage encountered in the colons of animals infected with VPI 10463 and BI1. Disease severity also correlated with levels of C. difficile cytotoxic activity in intestinal tissues and elevated blood neutrophil counts. Cefoperazone treated mice represent a useful model of C. difficile infection that will help us better understand the pathogenesis and virulence of this re-emerging pathogen.

The management of Clostridium difficile infection

INTRODUCTION/BACKGROUND

Clostridium difficile is the commonest cause of nosocomial diarrhoea. The epidemiology and clinical phenotype of the disease has dramatically changed with the global emergence of a virulent strain of C. difficile.

SOURCE

This review was compiled using data from individual studies and review articles identified from PubMed. The retrieved articles were also examined for additional references.

AREAS OF AGREEMENT

Appropriate and timely infection control measures are required to control C. difficile infection (CDI) in the hospital environment, and either oral metronidazole or vancomycin remains the mainstay of treatment depending on the severity of infection.

AREAS OF CONTROVERSY

The optimal method for diagnosing CDI remains unclear, as does the best therapeutic strategy for the management of multiple relapses. GROWING POINTS/AREAS TIMELY FOR DEVELOPING RESEARCH: Studies of new antimicrobial agents with activity against C. difficile are required to improve the management of multiply relapsing disease. The use of novel therapeutic approaches that do not require antimicrobials requires urgent research, including the use of immunological or vaccine-based regimen, bacteriotherapy or C. difficile-specific bacteriophages.

Historical perspectives on studies of Clostridium difficile and C. difficile infection

The initial period of studies on Clostridium difficile (published during 1978-1980) appeared to provide a nearly complete portfolio of criteria for diagnosing and treating C. difficile infection (CDI). The putative pathogenic role of C. difficile was established using Koch's postulates, risk factors were well-defined, use of a cell cytotoxicity assay as the diagnostic test provided accurate results, and treatment with oral vancomycin was highly effective and rapidly incorporated into practice. During the next 10 years, enzyme immunoassays (EIAs) were introduced as diagnostic tests and became the standard for most laboratories. This was not because EIAs were as good as the cell cytotoxicity assay; rather, EIAs were inexpensive and yielded results quickly. Similarly, metronidazole became the favored treatment because it was less expensive and quelled fears of colonization with vancomycin-resistant organisms, not because it was better than vancomycin therapy. Cephalosporins replaced clindamycin as the major inducers of CDI because they were so extensively used, rather than because they incurred the same risk. Some serious issues remained unresolved during this period: the major challenges were to determine ways to treat seriously ill patients for whom it was not possible to get vancomycin into the colon and to find methods that stop persistent relapses. These concerns persist today.

Decision-Making Analysis for Selection of Antibiotic Treatment in Intra-Abdominal Infection Using Preference Measurements

BACKGROUND

Antimicrobial therapy of abdominal infections is important to the prognosis of affected patients. The choice of antimicrobial therapy must consider effectiveness, safety, cost, and antibiotic resistance, among numerous factors. However, in reality, decisions are made assuming bioequivalence between regimens, without considering the specific attributes of any particular regimen. The objective was to determine the best antibiotic regimen for patients with community-acquired abdominal infection on the basis of a decision analysis that included effectiveness as well as safety, measured as adverse effects.

METHODS

A decision tree was built using information from a systematic review of the literature on the effectiveness of antimicrobial regimens tested in randomized clinical trials (RCTs) and the frequency and severity of adverse effects. The quality of the articles was assessed with the Oxford criteria for RCTs. The main outcome was preferences reported by surgeons, measured on a numeric scale. Preferences were obtained using a standard survey that reported each adverse effect with its respective intensity, reversibility, sequelae, duration of symptoms, and necessity for change of antibiotic. Each of the surgeons had to assign a value blindly from 0 to 10, where 10 was the most severe. A sensitivity analysis was conducted varying the frequency of adverse effects.

RESULTS

The regimens analyzed were amikacin-metronidazole, amikacin-clindamycin, ciprofloxacin-metronidazole, ampicillin-sulbactam, ceftriaxone-metronidazole, piperacillin-tazobactam, and ertapenem. The perceived severity of adverse effects reported were: Acute neuromuscular blockade (8.0), severe allergic reaction (7.5), ototoxicity (7.4), nephrotoxicity (7.1), antibiotic-associated colitis (7.0), peripheral neuropathy (5.3), general neurological symptoms (4.9), gastrointestinal symptoms (3.1), and other general symptoms (2.6). Favored regimens were ceftriaxone-metronidazole (1.15), ampicillin-sulbactam (1.24), piperacillin-tazobactam (1.27) and ertapenem (1.28). These strategies dominated the other therapeutic schemes. Sensitivity analysis showed no changes in the dominance reported when the frequency of adverse effects was maintained in the known clinical range.

CONCLUSIONS

Antibiotic regimens that contain aminoglycosides are not bioequivalent to those without aminoglycosides when effectiveness and adverse effects are considered simultaneously. Antibiotic regimens that do not use aminoglycosides must be the first line of treatment for abdominal sepsis acquired in the community.

Clindamycin and dentistry

Clindamycin is an antimicrobial agent that dentists use in the UK for infective endocarditis prophylaxis but rarely for other clinical situations that require antimicrobial intervention. This has been largely due to its association with acute pseudomembranous colitis. Up to date information on the efficacy and safety of this antimicrobial agent should be known before prescription.

Clostridium difficile: clinical disease and diagnosis

Clostridium difficile is an opportunistic pathogen that causes a spectrum of disease ranging from antibiotic-associated diarrhea to pseudomembranous colitis. Although the disease was first described in 1893, the etiologic agent was not isolated and identified until 1978. Since clinical and pathological features of C. difficile-associated disease are not easily distinguished from those of other gastrointestinal diseases, including ulcerative colitis, chronic inflammatory bowel disease, and Crohn's disease, diagnostic methods have relied on either isolation and identification of the microorganism or direct detection of bacterial antigens or toxins in stool specimens. The current review focuses on the sensitivity, specificity, and practical use of several diagnostic tests, including methods for culture of the etiologic agent, cellular cytotoxicity assays, latex agglutination tests, enzyme immunoassay systems, counterimmunoelectrophoresis, fluorescent-antibody assays, and polymerase chain reactions.

Pharmacokinetic and tolerance studies of cefpodoxime after single- and multiple-dose oral administration of cefpodoxime proxetil

Cefpodoxime proxetil, a third generation, broad-spectrum, oral cephalosporin, was administered in single doses of 100, 200, 400, 600, and 800 mg (dose expressed as cefpodoxime equivalents) and multiple doses of 100, 200, and 400 mg twice daily to healthy volunteers. The pharmacokinetics of the active metabolite, cefpodoxime, and tolerance of cefpodoxime proxetil were determined. Results from the single-dose study indicate that cefpodoxime exhibits nonlinear pharmacokinetics over the dose range of 100 to 800 mg. This nonlinearity is primarily due to differences in dose-normalized AUC and Cmax, urinary recovery, and half-life between one or more of the higher-dose treatment groups and the 100-mg dosing group. After multiple-dose (twice daily) administration for 15 days, steady state is achieved on the second day of dosing, and there is no drug accumulation. Cefpodoxime pharmacokinetics are linear with dose over the clinically relevant dosing range of 100 to 400 mg. Microbiologic and HPLC plasma assay results are highly correlated, with close agreement between HPLC- and microbiologic-determined pharmacokinetic parameter estimates. Cefpodoxime proxetil was well tolerated in both studies. The most frequent medical events were related to gastrointestinal problems and consisted of transient loose stools in three subjects in the single-dose study and antibiotic-associated diarrhea in one subject in the multiple-dose study.

Antibiotic use among children in an urban Brazilian slum: a risk factor for diarrhea?

Among a cohort of children in a poor urban setting in Brazil, the relative risk for the occurrence of a new episode of diarrhea in the two weeks following antibiotic use vs all other weeks was 1.44 (95% confidence interval (CI) = 1.33, 2.45). Among children ever [corrected] exposed to antibiotics, the odds ratio was 1.34 (95% CI = 0.84, 2.16) after stratifying by individual child and controlling for previous diarrhea. Further research is needed to confirm whether antibiotics are a risk factor for diarrhea in such settings.

Adverse reactions to furazolidone and other drugs. A comparative review

Furazolidone is a synthetic nitrofuran with a broad spectrum of antimicrobial action and has been widely used in the treatment of gastrointestinal infections. This article reviews the adverse reactions to furazolidone reported in the world literature. Of 10,443 adults and children who were treated with the drug, approximately 8.3% (864) experienced such reactions. Because some of these patients had more than 1 adverse reaction, 1178 reactions were reported in these studies. Nausea with vomiting, the commonest adverse reaction, was reported by 51% of the 864 patients who experienced adverse reactions. The authors compare the adverse reactions to furazolidone with those reported for other antimicrobial and antiprotozoal drugs that are frequently used to treat gastrointestinal infections.

Diarrhoea and constipation

Drug-induced constipation is mostly caused by changes in gut motility, whilst diarrhoea is more frequently caused by an increase in intestinal fluid secretion. In both instances the drug has to reach the enteric nervous system or the enterocyte, either via the blood or from the lumen, in sufficient concentrations to affect the mediators that regulate motility and fluid transport. Diarrhoea and constipation are frequently mentioned as side-effects of drugs, and therapeutic agents for almost all organ systems have been implicated. However, both these side-effects are usually mild or moderate, and rarely necessitate interruption of drug treatment. An exception to this rule is the antibiotic-associated colitis seen in patients treated with antibiotics such as lincomycin or clindamycin; in principle almost all antibiotics may cause this severe and potentially life-threatening complication. Other rare forms of severe, drug-induced colitis and diarrhoea result from toxic or anaphylactic reactions against gold preparations, cytostatic agents and sulphonamides. Ischaemic colitis due to vascular complications has been described in some women taking oral contraceptives, and in patients treated with vasopressin or digitalis.

Impaired colonic fermentation of carbohydrate after ampicillin

The aim of this study was to investigate the effect of ampicillin on the ability of the human colon to ferment carbohydrate. The effect of ingesting a drink containing 20 g of lactulose on stool output and breath hydrogen production was measured in 13 normal volunteers before and during administration of ampicillin (2 g/day). Small bowel and whole gut transit times were also measured to exclude any direct effect of ampicillin on motor activity. Ingestion of lactulose did not increase stool weight or frequency under control conditions, but during administration of ampicillin, lactulose caused increases in stool weight (p less than 0.02) and frequency (p less than 0.01), in the percentage of unformed stools (p less than 0.001), and in the excretion of galactose and fructose in stool samples collected from 2 volunteers. Administration of ampicillin also significantly reduced the area under the breath hydrogen profile (p less than 0.03). Mouth-to-cecum transit of the lactulose drink was prolonged during ampicillin ingestion (p less than 0.01) but there was no significant change in the whole gut transit time. These results suggest that ampicillin impairs colonic fermentation of carbohydrate and a diet high in unabsorbable carbohydrate increases the risk of antibiotic-associated diarrhea.

Electron microscopy of the intestine and rectum in acquired immunodeficiency syndrome

To provide a better understanding of the morphologic changes that take place in the intestine and colon in acquired immunodeficiency syndrome (AIDS), electron microscopy was performed on intestinal or colonic biopsy specimens obtained from 6 patients with AIDS and from 2 patients with AIDS-related lymphadenopathy syndrome. Cryptosporidia were attached to the plasma membrane of epithelial cells in 2 patients and were noninvasive. An invasive protozoan organism identified as Microsporidia was found in 1 patient. Evidence for epithelial cell injury was limited. Unusually prominent secretory granules in colonic epithelial cells (a morphologic counterpart of secretion) was found in 2 patients. Tubuloreticular structures were observed in 7 patients. The structures were found in endothelial cells, lymphocytes, monocytes, intraepithelial lymphocytes, and free in the capillary lumen. Tube- and ring-shaped forms were observed in 2 patients, prominent intraepithelial mast cells in 4 patients, rectal spirochetosis in 1 patient, and pseudomembranous colitis in 1 patient with intestinal and systemic shigellosis. Vesicular rosettes, retroviruses, other viruses, and Mycobacterium avium-intracellulare were not observed. These observations expand our knowledge of morphologic changes in the colonic and intestinal mucosa in patients with AIDS. Tubuloreticular structures are so prominent, in contrast to our previous electron-microscopic observations in other disease and normal states of the intestine and colon, that their finding (though clearly nonspecific) may be a clue to the diagnosis of AIDS in an otherwise equivocal situation.

Medical management of antimicrobial-associated diarrhea and colitis

Gastrointestinal complications, including diarrhea, may occur with virtually all antimicrobial agents. Such diarrhea may represent either a common, nonspecific adverse effect, or it may be one of the manifestations of antimicrobial-associated colitis (AAC), a potentially fatal complication. Clostridium difficile and a cytotoxin neutralized by Clostridium sordellii antitoxin has been isolated from the stools of nearly all patients with antibiotic-associated pseudomembranous colitis, many patients with AAC, and approximately 20% of those with antimicrobial-induced diarrhea. Demonstration that C. difficile is responsible for cytotoxin production has allowed for specific therapy for these disorders. General treatment measures include discontinuation of the causative antimicrobial agent(s), bowel rest, and supportive care with fluids, electrolytes and colloids, if necessary. Antiperistaltic agents and corticosteroids are not recommended. Various antimicrobials demonstrate potential efficacy in treating AAC in humans. Oral vancomycin is the most widely tested and is currently the treatment of choice. It achieves high concentrations in the feces and is very active against C. difficile in doses of 125-500 mg by mouth every six hours. Other potentially useful but inadequately tested antimicrobials include metronidazole (500 mg by mouth every eight hours) and bacitracin (25,000 units by mouth every six hours). Tetracycline has been employed with some success in nonspecific antibiotic-associated diarrhea, although it is as yet untested in humans with AAC and may induce diarrhea itself. Both miconazole and rifampin are highly effective against C. difficile in vitro but have not been evaluated in AAC. Anion-exchange resins bind the cytotoxin found in stools of patients with AAC. Cholestyramine has been used with variable response in oral doses of 4 g every six to eight hours. Since these resins may also bind vancomycin, resulting in lowered vancomycin concentrations in the stool, combination therapy should be used cautiously. With specific therapy directed against the toxin and aggressive supportive therapy, surgical intervention is rarely necessary. More recently, investigations have been directed at using bacterial preparations to suppress C. difficile by restoring the normal flora. The development of immunological agents (i.e., vaccines, toxoids, antitoxins) for the prevention or treatment of AAC would be a significant advance in therapy.

Treatment of Clostridium difficile colitis and diarrhea with vancomycin

Toxigenic Clostridium difficle is the major cause of antibiotic-associated colitis and is susceptible to vancomycin at fecal concentrations achieved with oral therapy. The effect of oral vancomycin was studied in 16 patients with C. difficile-related diarrhea or colitis, 12 of whom had colitis documented by endoscopy, biopsy, and/or barium enema. Four patients had antibiotic-associated diarrhea and possibly antibiotic-associated colitis, because sigmoidoscopy either showed normal results (two patients) or was not performed (two patients). Nineteen episodes of diarrhea were treated with oral vancomycin in two dosage regimens for three to 14 days. Twelve patients received 2 g daily, and four patients initially received 1 g or less per day. Within 48 hours of the start of vancomycin therapy, 14 of 16 patients (87 percent) showed a decrease in temperature, abdominal pain and diarrhea. Diarrhea ceased completely within two days of the start of vancomycin in nine episodes, within three to seven days in six episodes, and within eight to 14 days in the remaining four episodes, and within eight to 14 days in the remaining four episodes. Diarrhea recurred in two of these patients (12 percent) when the drug inciting the initial episode of colitis was given again 42 days or more after vancomycin therapy was stopped; both patients responded again to retreatment with vancomycin. Oral vancomycin is an effective treatment of C. difficile-related colitis and diarrhea.

Epidemiology of antibiotic-associated colitis; isolation of Clostridium difficile from the hospital environment

Clostridium difficile is the most important cause of antibiotic-associated colitis. Using selective media, it was found that contamination with this organism was common in the environment of patients in the hospital with the disease. It was often found on floors, hoppers, toilets, bedding, mops, scales and furniture. This organism was also present on these items, but less often, in areas in which patients known to carry this hardy spore-forming organism had not been detected. Air, food and walls were negative. The organism was isolated from the hands and stools of asymptomatic hospital personnel. It was also found on surfaces in a patient's home. The importance of the various sources of the organism in its spread in the hospital is not known, and further studies are needed. It is suggested that enteric isolation precautions, and careful handwashing and cleansing of potentially contaminated surfaces and objects may be worthwhile when cases of antibiotic-associated colitis are identified.

Common adverse effects of antibacterial agents on major organ systems

Antibiotics contribute significantly to the management of the surgical patient. However, their potential for adverse effects, both toxic and allergic, must always be kept in mind. We have reviewed the major adverse reactions to antibiotics, so that side effects may be promptly recognized and treated. Armed with this information, the surgeon can more effectively utilize this valuable class of drugs for the benefit of the patient.

Acute right-sided hemorrhagic colitis associated with oral administration of ampicillin

Among 56 cases who presented to Kanto-Teishin Hospital complaining of bloody diarrhea or considerable hematochezia of acute onset, 8 cases (14.3%) were considered due to colitis associated with oral ampicillin therapy. The bloody diarrhea, often with abdominal cramps, began 2-7 days after starting the treatment. The dosage of ampicillin taken ranged from 2.0 to 4.5 g. Early total colonoscopy and biopsy revealed marked mucosal hemorrhage with minimal or no inflammatory changes mainly in the right colon. Rectum and sigmoid colon are completely normal except in one case. Symptoms rapidly resolved after the endoscopy. At follow-up colonoscopy, performed 4-12 days later, the mucosal changes had cleared completely. There was no evidence to support a hypersensitivity reaction of the colonic mucosa to ampicillin. We believe that right-sided hemorrhagic colitis is one of the common forms of colitis associated with ampicillin. Its differentiation from other kinds of acute colitis and the importance of early total colonoscopy are discussed.

Necrotizing colitis in patients with cancer

Necrotizing lesions of the colon occur in patients with malignancy. We identified 26 patients with cancer (23 with acute leukemia and three with solid tumors) who died from necrotizing colitis. Autopsies revealed three pathologic categories: pseudomembranous colitis in 69 per cent, agranulocytic colitis in 19 per cent and ischemic colitis in 12 per cent. Most died from sepsis. A comparison of characteristics was made with a control population matched for diagnosis, age, cause of death and duration of neoplasia. Nearly all patients in both groups had fever and were granulocytopenic secondary to chemotherapy. Most received antineoplastic and antimicrobial regimens during the month prior to their terminal illness. Abdominal pain and distention, stomatitis and necrotizing pharyngitis were frequently associated with colitis. Hyperbilirubinemia was a frequent late complication in those with colitis and the control group. Single and multiorganism septicemia were found more frequently in patients with colitis. As antemortem diagnosis was unusual, aggressive attempts at diagnosis are necessary to assess the true incidence of this disorder and the best therapy.

Antibiotic-associated pseudomembranous colitis in children

Antibiotic-associated colitis is a rare complication of antimicrobial therapy in children. Ampicillin, penicillin, and clindamycin are the drugs most frequently reported to cause pseudomembranous colitis in pediatric patients. This diagnosis should be suspected in any child with significant diarrhea during or after a course of antimicrobial therapy, especially if the diarrhea persists after the drug has been discontinued. The diagnosis is established by proctoscopic findings of typical plaques of pseudomembranes. Most cases resolve promptly when the implicated antibiotic is stopped; however, the disease can be fulminant, progressing to toxic megacolon, peritonitis, and shock. Therapy of patients who have persistent diarrhea after the offending antibiotic has been discontinued should include oral vancomycin. Close fluid management is crucial for survival.

Pseudomembranous colitis associated with ampicillin and erythromycin therapy: report of a case

Pseudomembranous colitis has been observed increasingly often after therapy with several antibiotics. This report describes the case of a patient in whom pseudomembranous colitis developed in association with ampicillin, an extremely rare complication of this drug, and erythromycin, a drug that has not been previously reported to cause the disease. Clinical and pathologic features, pathogenesis, and management are discussed. Early diagnosis and treatment are extremely important to reduce the significant morbidity and mortality associated with this disorder.

Pseudomembranous colitis associated with antibiotic therapy in a child: report of a case and review of the literature

A case of pseudomembranous colitis is presented in a child with multiple medical problems who received intraoperative antibiotics. Despite aggressive medical management and operative intervention, the patient died. All patients who develop diarrhea after receiving antibiotics should be suspected of having pseudomembranous colitis. Sigmoidoscopy and hyaque enema should be performed to confirm the diagnosis and all antibiotics should be discontinued. Aggressive medical management consisting of intravenous fluids, albumin, lactinex granules, fecal enemas, and cholestyramine should be instituted. Surgery should be considered only in the face of perforation, toxic megacolon, peritonitis, and failure of medical management with disease limited to the colon.

Toxic and allergic manifestations of antimicrobials

All antimicrobial drugs may produce toxic and allergic reactions. Penicillins and cephalosporins cause the greatest number of allergic reactions and should not be used for treatment of minor infections in patients with a history of an adverse reaction. If no alternative antibiotic will suffice for treatment of a serious infection, skin testing is necessary. Two commonly used antimicrobials, clindamycin and isoniazid, can have potentially fatal toxic effects.

Antibiotic-induced colitis implication of a toxin neutralised by Clostridium sordellii antitoxin

A toxin(s) has been demonstrated in the stools of two patients with antibiotic-associated colitis. This toxin(s) was heat-labile, was rapidly lethal for hamsters, increased vascular permeability in rabbit skin, and was cytotoxic for cells in tissue-culture. It was neutralised by Clostridium sordellii antitoxin but not by antitoxins prepared against other clostridia; Escherichia coli, and Vibrio cholerae toxins. These characteristics were identical to those of a toxin implicated in the aetiology of antibiotic-induced colitis in the hamster. One patient improved rapidly after treatment with oral vancomycin, and at the same time the toxin disappeared from the stool.