Intravesical administration of bacillus Calmette-Guerin has been shown to be 
highly effective treatment of superficial bladder cancer. Complications from 
bacillus Calmette-Guerin therapy are usually minor but serious and even fatal 
reactions can occur. Five recent cases illustrate the gravity of bacillus 
Calmette-Guerin sepsis. One man with severe debility and the organic brain 
syndrome died acutely with a fever of 40 C. Two men had frank sepsis that 
progressed to multiorgan failure and death. Sepsis progressed despite the use of 
isoniazid, rifampin and streptomycin. Two men who had equally progressive sepsis 
with intravesical bacillus Calmette-Guerin survived with the use of cycloserine 
for the first 72 hours of treatment. Triple antituberculous antibiotics, 
including cycloserine, may be lifesaving. Sepsis resulted from intravenous 
absorption through inflamed or disrupted urothelium. Bacillus Calmette-Guerin 
treatment should not be administered in the presence of severe cystitis or after 
grossly traumatic catheterization.