Neutropenia induced by high-dose intravenous benzylpenicillin in treating neurosyphilis: Does it really matter?

Ceftazidime/avibactam-induced severe neutropenia: A case report

Ceftazidime/avibactam is an important option for the treatment of infections caused by multidrug-resistant gram-negative bacteria. Haematological abnormalities are rare adverse events. We describe a case of a 63-year-old male who developed severe neutropenia following exposure to ceftazidime/avibactam in the intensive care unit for the treatment of abdominal infections. Six days after ceftazidime/avibactam was prescribed, the patient experienced a sheer drop in absolute neutrophil count, down to a minimum of 0.13 × 109 /L. A bone marrow examination showed neutrophilic maturation arrest. After careful screening of all drugs used by the patient and other potential causes of severe neutropenia, ceftazidime/avibactam was suspected to be the most likely culprit and was therefore replaced by cefoperazone/sulbactam, while a dose of colony-stimulating factor was given. The next day, neutrophils rose to 3.64 × 109 /L. To the best of our knowledge, this is the first case report of severe neutropenia associated with ceftazidime/avibactam. When neutropenia occurs during treatment, the clinician should keep this possibility in mind. Regular monitoring of neutrophil counts for timely recognition, immediate discontinuation of the drug and substitution of antibiotics are key steps in management.

Ceftriaxone-induced neutropenia successfully overcome by a switch to penicillin G in Cardiobacterium hominis endocarditis

Leukopenia, including agranulocytosis, is a severe complication of treatment with all β-lactam antibiotics. Its incidence increases with age. Cardiobacterium hominis endocarditis after implantation of an aortic valve bio-prosthesis in a 77-year-old woman was treated with ceftriaxone 2 g/day plus gentamicin 160 mg/day intravenously. On Day 25 of treatment, blood leukocytes had decreased to 1800/μl (neutrophils 370/μl). Antibiotic therapy was switched to penicillin G 20 million international units (IU)/day. Thereafter, blood leukocytes including neutrophils normalized suggesting that penicillin G was less bone marrow-toxic than ceftriaxone. High-dose ciprofloxacin, the alternative to penicillin G, was avoided because of the risk of cognitive and behavioral side effects. The present case suggests that with close laboratory monitoring a β-lactam with differing side chains should not be considered contraindicated after β-lactam antibiotic-induced neutropenia.

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.

Post-treatment serological changes in some patients with early syphilis exhibit a parabolic trend

Early syphilis accounts for a large proportion of patients with syphilis. Non- Treponema pallidum tests are commonly used to assess treatment effectiveness by analyzing the serological titer before treatment and six months after treatment. However, serological changes during the first three months after completion of treatment have not been completely understood. This prompted us to investigate whether serum titers of patients exhibit a continuous decrease post-treatment and to assess the trend of change in serological titer during this period. One hundred and seventy-three eligible patients with early syphilis were included in the analysis. Pre-treatment serological titers and those at three and six months post-treatment were compared and analyzed. Serological recovery was defined as a 4-fold or greater decrease in titer from pre-treatment level. Forty patients (23.1%) were found to have an increased serum titer at three months after treatment. Among the 40 patients, 13 patients had primary syphilis, 5 patients had secondary syphilis, and 22 patients had early latent syphilis. The proportion of patients with primary syphilis was higher, and their initial titers were significantly lower. No significant differences were observed with respect to age, gender, or initial treatment. The assessment results of 17 patients (9.8% of the total patients) change. Serological changes in some patients exhibit a parabolic pattern that may affect the clinician’s assessment of patient recovery. Therefore, more frequent assessment of serological titer might be required within the first six months post-treatment.

Beta-lactam-induced severe neutropaenia: a descriptive study

The objectives of this study were to describe the characteristics and natural history of beta-lactam-induced severe neutropaenia and to evaluate the risk of recurrences after another beta-lactam readministration. Reports of pure agranulocytosis associated with a beta-lactam exposure within the 10 days preceding the neutropaenia were extracted from the French Pharmacovigilance Database over the year 2010. Cases with another evident cause or more likely attributable to another drug were excluded. Data were analyzed for demographics, clinical and biological features, prognosis factors, granulocyte colony stimulating factors administration and outcome. Sixty-two cases were included (median age: 65 years). The median duration of treatment before neutropaenia was 16 days. In 47% of cases, the diagnosis was made on a systematic blood cell count. The median neutrophil count at nadir was 0.125 × 10⁹ /L, and bone marrow examination evidenced features of neutrophilic maturation arrest or aplasia in 21 patients, hyperplasia of granulopoietic cells in three and normal findings in five. Three patients developed severe sepsis. All but one recovered a normal blood cell count within 2-56 days after beta-lactam discontinuation. The last patient died from recurrent severe septic shock. No significant effect of granulocyte colony stimulating factor on the mean duration of haematological recovery was found. Among the 21 patients who later received another beta-lactam, two experienced recurrence of the neutropaenia after receiving a beta-lactam from another subfamily. Beta-lactam-induced agranulocytosis was usually observed after prolonged treatment, and severe complications are uncommon. In most patients, a subsequent treatment with another beta-lactam was well tolerated.

Hematopoiesis and the bacterial microbiome

Recent studies have revealed that the intestinal bacterial microbiome plays an important role in the regulation of hematopoiesis. A correlation between adverse hematologic effects and imbalance of the intestinal microbiome, or dysbiosis, is evident in several human conditions, such as inflammatory bowel disease, obesity, and, critically, in the setting of antibiotic exposure. Here we review the effects of gut dysbiosis on the hematological compartment and our current understanding of the mechanisms through which changes in the bacterial microbiome affect hematopoiesis.