NEWPORT BEACH, CALIF. – Use of atovaquone or pentamidine for Pneumocystis jiroveci pneumonia (PJP) prophylaxis was associated with an increased incidence of nocardiosis in allogeneic hematopoietic stem call transplant (HSCT) recipients at the University of California, Los Angeles, according to a review of patient records.
Of 10 cases of late-onset nocardiosis identified among patients who received HSCT between Jan. 1, 2000, and Aug. 30, 2017, 9 cases occurred in 411 patients (2.2%) treated between 2012 and 2017 – a period of increased use of atovaquone prophylaxis, compared with only 1 in 575 patients (0.17%) treated in the prior 12 years when trimethoprim-sulfamethoxazole (TMP-SMX) was used for prophylaxis, Alfonso Molina reported in a poster at the Acute Leukemia Forum of Hemedicus.
Nocardiosis is rare among allogeneic HSCT recipients, with a reported incidence of 0.3%-1.7%, and the preferred agent for its treatment – TMP-SMX – can also prevent nocardial infections when it is used for PJP prophylaxis following HSCT, Mr. Molina, a medical student at the University of California, Los Angeles, said in an interview. However, beginning in 2012 at UCLA, atovaquone was increasingly used in place of TMP-SMX for PJP prophylaxis, he explained.None of the 575 patients treated between 2000 and 2012, versus 119 of the 411 treated after 2012, received atovaquone, he reported.
To assess the potential relationship between the use of atovaquone and the increased incidence of nocardiosis, he and his colleagues reviewed patient medical records and UCLA Clinical Microbiology Laboratory culture results.