The feasibility of rifampicin Re-administration in patients with tuberculosis and Clostridioides difficile infection.

Background: The effects of a rifampicin (RIF) on the evolution of Clostridioides difficile infection (CDI) have not previously been investigated and there is currently no consensus on whether RIF re-administration is feasible.

Methods: This retrospective observational study included consecutive tuberculosis (TB) patients diagnosed with comorbid RIF-associated CDI (RA-CDI) using strict diagnostic criteria. We investigated the association between RA-CDI and clinical outcomes, and also examined the feasibility of re-administering RIF.

Results: Out of the 11,230 patients were admitted to TB ward at our hospital, 156 TB patients (1.4%) were diagnosed with CDI and the overall incidence of CDI was calculated as 2.1 cases per 10,000 patient-days. Of 156 patients with CDI, 86 were diagnosed with RA-CDI, of whom 28 (32.6%) were re-administered with RIF. In the re-administration group, time to initial sputum smear conversion was significantly shorter than for patients who were not re-administered with RIF (42 days [interquartile range, IQR: 35-65] vs. 55 days [IQR: 44-70], p = 0.041). Further, RIF re-administration significantly reduced length of hospital stay (69 days [IQR: 66-82] vs. 81 days [IQR: 72-89], p = 0.014). Ten patients (35.7%) had recurrent CDI after RIF re-administration. On the other hand, 15 patients (53.6%) were able to continue their TB treatment, including the RIF regimen.

Conclusions: The present study strengthens the argument for including RIF in the list of antibiotics that can induce CDI, particularly in elderly men suffering from underlying conditions. Although careful attention must be paid to the possibility of CDI recurrence, a strategy of re-administration of RIF is feasible.