Florastor (Saccharomyces boulardii) Dosing with Dexlansoprazole 60 mg
Take Florastor (Saccharomyces boulardii) 1 gram daily (two 500 mg capsules or one 1-gram packet) divided into two doses while on dexlansoprazole 60 mg, continuing for the duration of PPI therapy plus 7 days after stopping. 1, 2
Rationale for This Dosing
The 1 gram daily dose (500 mg twice daily) is the evidence-based regimen used in the landmark randomized controlled trial that demonstrated efficacy for preventing C. difficile recurrence when combined with standard antibiotics. 2
This same dose was effective in reducing recurrence rates from 64.7% to 34.6% in patients with recurrent CDI, which matches your clinical scenario of prior CDI. 2
PPIs like dexlansoprazole increase CDI risk by raising gastric pH and disrupting the gut microbiome, making prophylactic probiotics particularly relevant in your case with prior CDI history. 1
Timing and Duration
Start S. boulardii immediately while on the PPI and continue for 7 days after discontinuing dexlansoprazole. 1
Take one dose in the morning and one in the evening, ideally with meals to improve tolerability, though timing relative to the PPI dose is not critical since S. boulardii is a yeast and not affected by gastric acid. 2
Safety Considerations
S. boulardii is contraindicated if you are immunocompromised (including HIV with low CD4 count, active chemotherapy, or high-dose immunosuppressants) due to rare but serious risk of fungemia. 1
The probiotic has an excellent safety profile in immunocompetent patients, with no serious adverse events reported in clinical trials. 2
Do not use S. boulardii if you have a central venous catheter, as this increases fungemia risk even in non-immunocompromised patients. 1
Evidence Strength and Nuances
The recommendation is based on two randomized controlled trials showing benefit specifically for recurrent CDI prevention when combined with antibiotics (vancomycin or metronidazole). 1, 2
One negative trial in elderly hospitalized patients found no benefit for preventing antibiotic-associated diarrhea, but this study did not specifically target patients with prior CDI history like yours. 3
The World Society of Emergency Surgery guidelines support prophylactic probiotics during high-risk periods in non-immunocompromised patients, though they note the evidence quality is moderate (Grade 2B-2C). 1
Critical Pitfalls to Avoid
Do not reduce the dose below 1 gram daily; lower doses were not studied and may be ineffective. 2
Do not stop the probiotic abruptly when finishing the PPI—continue for 7 additional days to allow gut microbiota stabilization. 1
If you develop new diarrhea while on this regimen, do not assume it is simply antibiotic-associated diarrhea; test for C. difficile toxin immediately, as S. boulardii does not treat active CDI and you will need vancomycin or fidaxomicin. 4