Background and importance Clostridium difficile (CD) colonises the human intestinal tract after the normal flora has been disrupted (in association with antibiotic therapy). Clinical guidelines use fidaxomicin as first-line treatment in patients at greater risk for recurrence (age >65 years, compromised immunity, severe CD infection) in accordance with 2021 Infectious Diseases Society of America (IDSA).

Aim and objectives Evaluation of the cost increase in the treatment of CD if patients are treated with fidaxomicin instead of vancomycin after the failure of first-line treatment or as first-line treatment according to the age recommendations of the IDSA.

Material and methods Retrospective observational study that included patients diagnosed with pseudomembranous colitis and treated with oral vancomycin for CD from 1 October 2020 to 30 September 2021. Clinical sources used were from FarmaTools and the Electronic Medical Record Selene.

Results 97 patients were analysed; 48.45% men, median age 72 (SD 16) years. 9 were empirically treated. 88 pacients were positive for CD. 5 patients died from another pathology during treatment (3 during the first-line and 2 during the second-line treatment).

73 patients (75.26%) (43.84% men) only needed one line of treatment with vancomycin to achieve a cure. The cost of vancomycin treatment for these patients was €3216.

19 patients (19.59%) (63.16% men) required a second (15 patients) or third line (4 patients) of treatment after the failure of the previous lines. The cost of vancomycin treatment for these patients was €2266. These patients could have been treated with fidaxomicin. The total cost would have been increased to €30 300.

71 patients (73%) at the time of diagnosis were older than 65 years; 83% first line, 9.86% second line and 7.14% third line. The cost of vancomycin treatment for these patients was €5461. Following the IDSA criteria, these patients could have been treated from the beginning with fidaxomicin. The total cost would have been increased to €102 453.

Conclusion and relevance The use of fidaxomicin represents a very high increase in healthcare costs compared to vancomycin. In our study all the patients were cured with the use of vancomycin. It should also be noted that in clinical trials and meta-analyses, fidaxomicin achieves a modest superior efficacy compared to vancomycin.

Conflict of interest No conflict of interest