Clinical evaluation of antimicrobial agents in urinary tract infections (urinary tract infections in paraplegics. 2)

摘要

Our clinical evaluation on the effectiveness of nalidix i c acid in treating chronic urinary infections was poor and so different from the general opinions that it seemed to require considerations from various angles. Nalidixic acid was no t so active to Gram-negative organisms, although it had been called to be very sensitive in many papers. To understand such opinions, two reasons had to be considered. The first was the difference between the standards based on blood or urinary concentration to decide the sensitivity of urinary bacteria. The former was the better standard than the latter. The second was the rapid development of resistance to nalidixic acid. This characteristic was fatal clinically. Data on the concentr a tions of nalidixic acid in blood and urine by bioassay and chemical assay suggested its difficult absorption and high inactivation in vivo. Considering above facts, clinical evaluation of nalidixic ac i d on urinary infections would be expected to be poor. Many papers, however, have reported as excellent drug uniformly. What is the reason why such contradiction does occur ? It may depend on little attention to the characteristics of urinary infections. That is, acute urinary infection uncomplicated by structural abnormalities of the urinary tract so often subsides spontaneously that the efficacy of an antibacterial drug can be evaluated only by carefully conducted controls. Double blind method was recommended as one of the concrete methods.