Agranulocytosis associated with semisynthetic penicillins and cephalosporins. Report of 7 cases

Intestinal microbiota modulation and improved growth in pigs with post-weaning antibiotic and ZnO supplementation but only subtle microbiota effects with Bacillus altitudinis

The objective was to evaluate the effect of dietary Bacillus altitudinis spore supplementation during day (D)0–28 post-weaning (PW) and/or D29–56 PW compared with antibiotic and zinc oxide (AB + ZnO) supplementation on pig growth and gut microbiota. Eighty piglets were selected at weaning and randomly assigned to one of five dietary treatments: (1) negative control (Con/Con); (2) probiotic spores from D29–56 PW (Con/Pro); (3) probiotic spores from D0–28 PW (Pro/Con); (4) probiotic spores from D0–56 PW (Pro/Pro) and (5) AB + ZnO from D0–28 PW. Overall, compared with the AB + ZnO group, the Pro/Con group had lower body weight, average daily gain and feed intake and the Pro/Pro group tended to have lower daily gain and feed intake. However, none of these parameters differed between any of the probiotic-treated groups and the Con/Con group. Overall, AB + ZnO-supplemented pigs had higher Bacteroidaceae and Prevotellaceae and lower Lactobacillaceae and Spirochaetaceae abundance compared to the Con/Con group, which may help to explain improvements in growth between D15–28 PW. The butyrate-producing genera Agathobacter, Faecalibacterium and Roseburia were more abundant in the Pro/Con group compared with the Con/Con group on D35 PW. Thus, whilst supplementation with B. altitudinis did not enhance pig growth performance, it did have a subtle, albeit potentially beneficial, impact on the intestinal microbiota.

A Review of β-Lactam-Associated Neutropenia and Implications for Cross-reactivity

OBJECTIVE

To review the incidence, management, and current understanding of the pathophysiology of β-lactam-induced neutropenia and to critically evaluate the practicality and safety of direct substitution to an alternative β-lactam in the setting of this reaction.

DATA SOURCES

A literature analysis using the PubMed and Ovid search engines (July 1968 to October 2020) was performed using the search terms neutropenia, leukopenia, β-lactam, nonchemotherapy, agranulocytosis, and G-CSF (granulocyte colony-stimulating factor).

STUDY SELECTION AND DATA EXTRACTION

The included English-language studies evaluated the incidence, mechanism, and/or management of β-lactam-induced neutropenia in pediatric or adult patients.

DATA SYNTHESIS

Drug-induced neutropenia is a well-documented adverse reaction of β-lactam antibiotics, with an incidence of approximately 10% following at least 2 weeks of intravenous therapy. However, multiple gaps in knowledge remain in the mechanism of pathophysiology and optimal management of this reaction. Both direct toxic and immune-mediated mechanisms have been implicated. Although the cornerstone of management includes cessation of the offending agent, controversy exists on the appropriateness of direct substitution or future use of an alternative β-lactam.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Given the frequency of use and superiority of β-lactams over alternative therapy for several infectious disease states, practical recommendations are needed on the management and safe use of β-lactams following β-lactam-induced neutropenia.

CONCLUSION

Future use of β-lactams with differing R1 side chains, particularly those from a separate class, should not be deemed contraindicated following β-lactam-induced neutropenia and may be considered when indicated, with close laboratory monitoring.

Neutropenia secundaria a betalactámicos. Una vieja compañera olvidada

Beta-lactam-induced neutropenia has been a well-recognized problem since the initiation of penicillin use. It generally develops following high-dose beta-lactam treatment lasting longer than 10 days, and its frequency rises with increases in the cumulative antibiotic dose. Beta-lactam-induced neutropenia is frequently preceded by fever or rash, which can be considered alarm signs. Unlike neutropenia induced by other nonchemotherapy drugs, beta-lactam-induced neutropenia usually lasts less than 10 days and infrequently causes infectious complications or death. Although any beta-lactam agent can cause neutropenia, recent studies have focused on cases of piperacillin-tazobactam- or cefepime-induced neutropenia; a high incidence of neutropenia has been demonstrated during prolonged treatment with these antibiotics. The apparent contradiction with the results of clinical trials that did not detect this complication is due to the fact that they involved treatments shorter than two weeks. The potential for the development of neutropenia during lengthy intravenous treatment should be borne in mind in the development of new beta-lactams.

Transient pancytopenia. A report from the International Agranulocytosis and Aplastic Study

From a population-based study on the incidence of potentially drug-associated blood dyscrasias 28 cases were identified with pancytopenia. Who recovered within 90 days after diagnosis. Early recovery occurred more frequently in patients showing normal or increased cellularity of the bone marrow than in patients with bone marrow hypoplasia. Median recovery times of leukocytes were 14 and 10 days and of platelets 21 and 9 days in patients with and without bone marrow hypoplasia, respectively. Age and sex distribution were similar in both groups. Of 28 patients, 11 reported a period of fever before onset of pancytopenia. Sixteen patients in whom information on drug use was available had taken a median of 4 drugs before the onset of symptoms that were related to pancytopenia. From these results we present the hypothesis that transient pancytopenia with or without marrow hypoplasia can be the expression of the same type of bone marrow injury and that drugs or viral infections should be considered as etiological factors.

Drug-induced agranulocytosis

Agranulocytosis is a rare but potentially serious adverse side effect of many drugs. Although it was recognised as an idiosyncratic type of drug reaction more than 50 years ago, its pathogenesis is still not fully understood. Drug-related antibodies are responsible for the neutropenia in the so-called 'immune' or 'aminopyrine' type of agranulocytosis. In contrast to former assumptions, the disappearance of leucocytes is not only due to rapid destruction of circulation cells, but it can result also from failure of the production of granulopoetic cells. In some other groups of drugs there is no evidence of immune-mediated disease, but direct toxicity to bone marrow cells has been observed using biochemical methods or inhibition of the growth of granulopoetic colonies in semisolid culture media. Until now it has not been possible to define the enzymatic abnormality which could explain this metabolic type of idiosyncrasy. The quantification of the incidence of potentially drug-induced agranulocytosis in general, and in particular its association with single drugs, requires studies on large populations and the use of strict epidemiological methodology to prevent reporting of grossly biased results. Data from recent case control studies show definitely lower risks for some relevant groups of drugs than formerly appreciated. As expected, agranulocytosis has been observed in association with some recently introduced drugs. This underlines the necessity for continued postmarketing monitoring of potential haematological side effects and for further case control studies to furnish data to aid prescribing physicians and health authorities in decision-making.

Cephalosporin-induced immune cytopenia in the dog: demonstration of erythrocyte-, neutrophil-, and platelet-associated IgG following treatment with cefazedone

Cephalosporin treatment in man has been associated with a low incidence of hemolytic anemia, thrombocytopenia, and neutropenia; some cases have been shown to be immune-mediated. This triad of blood dyscrasias was also demonstrated in our laboratory in a series of toxicity studies in dogs of two cephalosporin compounds, cefonicid and cefazedone; these studies provided evidence for drug-associated immune hemolytic anemia, based on conventional laboratory tests. To further investigate possible immune mechanisms of the cephalosporin-induced cytopenias, we measured erythrocyte-associated, platelet-associated (PAIgG), and serum antineutrophil IgG over the course of cephalosporin treatment, using highly sensitive 125I-staphylococcal protein A (SPA) assays, as well as the direct antiglobulin test; we compared these findings with the hematologic changes. Intravenous treatment with high doses of cefazedone (540 mg/kg/day, increased to a maximum of 840 mg/kg/day for 4 months or until hematologic effects were evident) resulted in a high incidence of anemia (7/14), thrombocytopenia (11/14), and neutropenia (7/14). Of the affected dogs examined, 6/7 with anemia, 9/9 with thrombocytopenia, and 7/7 with neutropenia showed increased levels of the respective cell-associated antibody, compared with untreated controls. Unaffected dosed animals generally did not show these changes. In 3/3 dogs examined following remission of thrombocytopenia, PAIgG returned to levels comparable with controls; as one of these dogs suffered a relapse, increased PAIgG was again observed. Animals sacrificed during cytopenic episodes showed cytologic and histologic evidence of increased hemophagocytosis. We conclude that antibody-mediated blood cell destruction contributes to all three cephalosporin-induced cytopenias in the dog.

Cephalosporin-induced changes in the ultrastructure of canine bone marrow

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

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

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

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

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

Adverse reactions and interactions with newer cephalosporin and cephamycin antibiotics

In this review, adverse reactions and interactions associated with the use of the newer cephalosporins and cephamycins are surveyed; special emphasis is placed on those reactions specific for some of these newer agents, namely disulfiram-like reactions with alcohol, effects on prothrombin synthesis, and lower gastrointestinal tract reactions. It is apparent that cephalosporins with a 3-methylthiotetrazole side-chain in the cephem nucleus cause clinically significant side effects more frequently than those without such a moiety. While still having a high degree of safety, cephalosporins with this chemical structure clearly have a higher degree of toxicity than those without this side-chain.