Bacillus Calmette-Guérin (BCG) is a live, attenuated strain of Mycobacterium bovis used primarily as an immunotherapeutic agent for the treatment of non-muscle invasive bladder cancer (NMIBC) and as a vaccine against tuberculosis. The 40mg dose is a standardized preparation for intravesical instillation in bladder cancer therapy. It functions as a potent nonspecific immune stimulant, inducing a robust local inflammatory and cell-mediated immune response within the bladder urothelium.
Adult: One intravesical instillation of 40mg (one vial) in 50 mL of sterile normal saline, retained in the bladder for 1-2 hours. Standard Induction: Once weekly for 6 weeks. Maintenance: Various schedules exist (e.g., 3 weekly instillations at 3, 6, 12, 18, 24, 30, and 36 months - SWOG protocol).
Note: 1. Administer via urethral catheter under aseptic technique. 2. Patient should refrain from excessive fluids 4 hours prior. 3. Instill slowly. 4. Ask patient to retain for 1-2 hours, repositioning every 15-20 minutes. 5. Patient voids in a toilet, and bleach should be poured into the toilet bowl (for 15-30 minutes) to inactivate any live bacteria. 6. Healthcare personnel must use appropriate PPE.
BCG attaches to fibronectin in the bladder wall, is internalized by urothelial cells and resident macrophages, and presents antigens to the immune system. This triggers a robust local Th1-type cell-mediated immune response characterized by infiltration of CD4+ and CD8+ T lymphocytes, natural killer (NK) cells, and macrophages. The release of cytokines (IL-2, IFN-γ, TNF-α, IL-8, IL-12) creates a cytotoxic inflammatory milieu that eradicates residual and microscopic tumor cells. It also induces trained immunity (innate immune memory) and may have direct antiproliferative effects.
Pregnancy: Category C (US FDA). Contraindicated. Live bacterial therapy; risk of fetal harm is unknown but potential for systemic infection exists. Not recommended.
Driving: Generally safe, but patients experiencing flu-like symptoms, malaise, or dizziness post-treatment should avoid driving or operating machinery.
| Immunosuppressants (Cyclosporine, Tacrolimus, Azathioprine, Mycophenolate) | Increased risk of disseminated BCG infection and reduced therapeutic efficacy. | Major |
| Corticosteroids (Systemic) | Suppresses cell-mediated immunity, increasing infection risk and reducing efficacy. | Major |
| Antibiotics (especially Fluoroquinolones, Isoniazid, Rifampicin) | May kill the live BCG bacteria if given concurrently, rendering therapy ineffective. | Major |
| Other Intravesical Therapies (e.g., Mitomycin, Gemcitabine) | Concurrent use not recommended. Sequential use should be spaced appropriately. | Moderate |
| Anticoagulants/Antiplatelets | May increase risk of hematuria post-catheterization. | Moderate |
Same composition (Bacillus Calmette-Guerin strain (40mg)), different brands: