Introduction
Florastor is a probiotic medication containing Saccharomyces boulardii lyo, a non-pathogenic yeast strain with demonstrated efficacy in preventing and treating various gastrointestinal disorders. Unlike bacterial probiotics, Florastor is a yeast-based preparation that remains unaffected by antibiotic therapy, making it particularly useful in antibiotic-associated diarrhea.
Mechanism of Action
Florastor exerts its therapeutic effects through multiple mechanisms:
- Enzyme production: Secretes proteases that degrade bacterial toxins and toxin receptors
- Immunomodulation: Enhances secretory IgA production and modulates inflammatory cytokines
- Pathogen inhibition: Competes with pathogens for epithelial binding sites
- Trophic effects: Stimulates brush border membrane enzymes and nutrient absorption
- Maintenance of barrier function: Helps preserve intestinal mucosal integrity
Indications
FDA-approved indications:- Prevention of antibiotic-associated diarrhea
- Treatment of Clostridium difficile-associated diarrhea (as adjunctive therapy)
- Prevention and treatment of traveler's diarrhea
- Acute infectious diarrhea in children and adults
- Irritable bowel syndrome symptom management
- Inflammatory bowel disease adjunctive therapy
- Helicobacter pylori eradication adjunctive therapy
Dosage and Administration
Adults and children >12 years: 250-500 mg (1-2 capsules) twice daily Children 2-12 years: 250 mg (1 capsule) twice daily Infants and children <2 years: 250 mg (1 capsule) once daily (contents may be mixed with cool liquid or food) Administration guidelines:- Take with or without food
- For antibiotic-associated diarrhea: Continue for several days after antibiotic course completion
- Contents of capsule may be opened and mixed with cool water, formula, or soft food
- Avoid mixing with hot liquids (>98.6°F/37°C)
Pharmacokinetics
Absorption: Not systemically absorbed; acts locally in gastrointestinal tract Distribution: Confined to intestinal lumen Metabolism: Not metabolized by human enzymes Elimination: Excreted unchanged in feces within 2-5 days after discontinuation Half-life: Not applicable (topical gastrointestinal action)Contraindications
- Hypersensitivity to Saccharomyces boulardii or any product components
- Patients with central venous catheters (risk of fungemia)
- Critically ill or immunocompromised patients
- Patients with known yeast allergies
Warnings and Precautions
- Fungemia risk: S. boulardii fungemia has been reported in critically ill, debilitated, or immunocompromised patients
- Central venous catheters: Avoid use in patients with CV catheters due to transmission risk
- ICU patients: Generally contraindicated in intensive care unit settings
- Pregnancy and lactation: Limited safety data; use only if clearly needed
- Pediatric use: Safety established in children >2 months of age
Drug Interactions
- Antifungals: Concurrent use with systemic antifungal agents (fluconazole, amphotericin B) may reduce efficacy
- No interactions with antibiotics, making it ideal for antibiotic-associated diarrhea prevention
- Immunosuppressants: Theoretical increased risk of fungemia in immunocompromised patients
Adverse Effects
Common (≥1%):- Flatulence
- Mild abdominal bloating
- Constipation (usually transient)
- Fungemia (in high-risk populations)
- Allergic reactions including anaphylaxis (very rare)
Monitoring Parameters
- Clinical response: Resolution of diarrhea symptoms
- Adverse effects: Monitor for abdominal discomfort or allergic reactions
- High-risk patients: Watch for signs of systemic infection (fever, chills)
- Duration of therapy: Assess need for continued use beyond acute episode
Patient Education
- Take as directed, typically twice daily with meals
- May take with antibiotics without reduced efficacy
- Store at room temperature (59°-86°F/15°-30°C)
- Keep capsule contents dry before mixing
- Report any signs of allergic reaction (rash, itching, swelling)
- Contact healthcare provider if symptoms worsen or persist beyond 48 hours
- For children: Mix capsule contents with cool liquid or soft food immediately before administration
- Do not use if package is damaged or expired
References
1. McFarland LV. Systematic review and meta-analysis of Saccharomyces boulardii in adult patients. World J Gastroenterol. 2010;16(18):2202-2222. 2. Szajewska H, Kołodziej M. Systematic review with meta-analysis: Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea. Aliment Pharmacol Ther. 2015;42(7):793-801. 3. Kelesidis T, Pothoulakis C. Efficacy and safety of the probiotic Saccharomyces boulardii for the prevention and therapy of gastrointestinal disorders. Therap Adv Gastroenterol. 2012;5(2):111-125. 4. FDA Orphan Drug Designations and Approvals. Accessed January 2023. 5. Product Monograph: Florastor® (Saccharomyces boulardii lyo). Biocodex Inc. 2022. 6. Dinleyici EC, Eren M, Ozen M, et al. Effectiveness and safety of Saccharomyces boulardii for acute infectious diarrhea. Expert Opin Biol Ther. 2012;12(4):395-410.