Evaluation of effectiveness, hyperkalaemia, and hepatotoxicity of trimethoprim-sulphamethoxazole prophylaxis for Pneumocystis jirovecii pneumonia in paediatric patients: A single-centre retrospective study

BACKGROUND

American guidelines recommend trimethoprim-sulphamethoxazole (TMP-SMX) for preventing Pneumocystis jirovecii pneumonia (PJP) in paediatric patients at doses of 5-10 mg/kg/d of the TMP component, administered either daily, three times weekly, or twice weekly. However, limited studies describe the effectiveness and safety of these prophylactic regimens. Our study aimed to assess the clinical effectiveness and incidence of adverse events associated with each TMP-SMX regimen in paediatric patients, and to identify risk factors for adverse events.

METHODS

We collected data regarding the onset of PJP, hyperkalaemia, and hepatotoxicity in patients aged 0-18 years who underwent prophylaxis with TMP-SMX from July 2018 to June 2023.

RESULTS

A total of 215 paediatric patients met the inclusion criteria. No patients developed PJP. Hyperkalaemia occurred in 14.7%, patients receiving TMP-SMX daily, 15.4% receiving it three times weekly, and 15.5% receiving it twice weekly. Hepatotoxicity was most frequent in patients receiving TMP-SMX twice weekly (19%), followed by those receiving it three times weekly (7.7%), and daily (5.9%). Younger patients were significantly more prone to developing hyperkalaemia or hepatotoxicity. Patients aged <1 year had the highest incidences of hyperkalaemia (56.5%), and those aged 1-2 years had the highest incidence of hepatotoxicity (25%).

CONCLUSIONS

No patient developed PJP under various dosage prophylactic regimens of TMP-SMX. However, our findings suggest the need to monitor potassium levels and hepatic function in patients undergoing any of the three TMP-SMX regimens. In particular, patients aged <1 year old and 1-2 years old face a higher risk of hyperkalaemia and hepatotoxicity, respectively.

Nocardia farcinica Brain Abscess: Report of 3 Cases

BACKGROUND

Central nervous system nocardial infection is a rarely reported disease that usually affects patients with predisposing and debilitating conditions but also the immunocompetent population. The most common variant affecting the brain is Nocardia farcinica. Management of brain nocardiosis is troublesome and requires consideration of the severity of the underlying systemic disease, the difficulties in identifying the bacterium, and the frequent delay in initiating adequate therapy.

CASE DESCRIPTION

We present 3 cases of N. farcinica brain abscess (single, multiloculated, and multifocal) diagnosed in 3 patients with predisposing factors that could be successfully cured. The patients underwent craniotomy, evacuation of the purulent collection, and partial resection of the abscesses' walls. Confirmation of N. farcinica species was achieved using specific polymerase chain reaction sequencing of the 16S ribosome RNA gene. Antibiotic therapy was selected on susceptibility tests and was maintained for 10 months (1 case) and 12 months (2 cases).

CONCLUSIONS

Brain nocardiosis needs to be suspected primarily (though not exclusively) in immunocompromised patients presenting with neurologic deficit and harboring intracerebral lesions resembling brain tumors. Early identification of the specific species is paramount in order to initiate long-term antibiotic therapy, acknowledging the inherent resistance of N. farcinica to third-generation cefalosporins and its susceptibility to trimethoprim-sulphamethoxazole. According to the literature, surgical excision or aspiration of the brain abscess seems to provide good chances of eradication of the disease. In our experience, successful outcome was achieved with subtotal resection and prolonged and adequate antibiotic therapy.

Stenotrophomonas maltophilia: An Emerging Pathogen in Paediatric Population

INTRODUCTION

Stenotrophomonas maltophilia (formerly Pseudomonas maltophilia/Xanthomonas maltophilia), a Gram- negative, non-fermenting bacillus, is being increasingly recognized as a threatening nosocomial pathogen, associated with significant mortality.

AIM

To determine the prevalence of infection, antimicrobial susceptibility pattern and clinical outcome of S. maltophilia in a paediatric population.

MATERIALS AND METHODS

This was a retrospective study conducted over a period of eight months, i.e., October 2015 to May 2016. All clinical samples received in the microbiology laboratory during the study period were processed using standard microbiological procedures. S. maltophilia isolates were selected. Antibiotic susceptibility was performed for levofloxacin and trimethoprim-sulphamethoxazole by Vitek 2C system (Biomerieux, France). Average length of stay and mortality caused by S. maltophilia infection was compared with age and sex matched controls without S. maltophilia infection.

RESULTS

A total of 16,234 clinical specimens were received in the microbiology laboratory in the study period, with 2,734 pathogenic bacteria isolated. A total of 1,339 (1.7% of total isolates) Gram-negative bacteria were isolated, out of which 414 were non-fermenters. Among the non-fermenters, 23 (5.5%) were S. maltophilia. Out of the 23 isolates, 15 (65.2%) were isolated from blood, 4 (17.3%) were isolated from urine and tracheal aspirate each. A total of 91.3% of strains were susceptible and 8.6% were resistant to trimethoprim-sulphamethoxazole. Total 80% of strains were sensitive and 20% had intermediate susceptibility for levofloxacin. None of the strains were resistant to levofloxacin. Average length of stay of patients with S. maltophilia infection was found out to be 23.3 days as compared to 44.8 days in controls. The average mortality of patients with S. maltophilia infection was found to be same as that of controls (35.2%).

CONCLUSION

S. maltophilia is becoming an important nosocomial pathogen and its isolation rate is reported to be increasing. Trimethoprim-sulphamethoxazole still remains the drug of choice but resistance has been reported for this drug as well. As its isolation is increasing, it is important to study the epidemiology, antimicrobial susceptibility profile and clinical outcomes of these isolates.