Aim:
To evaluate the appropriateness and rationale for pentamidine usage within the cancer care population at an Australian tertiary hospital.
This was assessed by identifying the indication for nebulised pentamidine for each patient and reviewing why other alternative pneumocystis jiroveci pneumonia (PJP) prophylaxis therapies were not utililised.
Methods:
Patients were identified by accessing the current pentamidine orders located within the infectious disease's day therapy unit. Commencing March 2021, data was collected prospectively using an audit tool until 30 patients were reached. Data collected primarily focused on the indication and appropriateness for nebulised pentamidine. Other collected data included: patient type, diagnosis, treatment duration, platelets at time of last dose, adverse drug reactions & severity & current immunosuppressive therapy. Patients receiving pentamidine outside of the cancer care population, trial participants and palliative patients were all excluded from the study. Patient allergy severity to cotrimoxazole was classified into five risk categories: very low, low, moderate, high and severe and actions for de-labelling were assigned using the decision support tool.
Results:
Allergy severities and consequent actions for cotrimoxazole therapy as first-line therapy over nebulised pentamidine were categorized as follows: very low - appropriate for direct de-labelling (n=3), low - appropriate for supervised direct oral challenge (n=1), moderate - may be appropriate for desensitization (n=13), high/severe - not appropriate for desensitisation (n=3), not applicable - not appropriate for retrial due to low platelets (n=7) and other (n=3).
Conclusions:
This study demonstrate that a large proportion of patients are prescribed pentamidine for known or suspected cotrimoxaole allergies. However, for patients with mild to moderate reactions, desensitisation and rechallenging should be utilised due to superiority, ease of access and cost effectiveness if ongoing PJP prophylaxis is required.