Background: Although it is an established surgical technique, transurethral
resection (TUR) is associated with a certain incidence of postoperative ba
cteriuria. Assessment was made whether the urothelial mucosal concentration
of an antibiotic administered before TUR was high enough to decrease the i
ncidence of urinary tract infection (UTI). Also investigated were factors p
redicting the organ concentration.
Methods: Forty-nine patients (45 men and four women aged 51-79 years with a
median age of 70 years) who underwent TUR between August 1996 and Septembe
r 1997 were enrolled in the study. Each patient received 200 mg of levoflox
acin (LVFX) about two hours before surgery. Blood and bladder urine were co
llected and urothelial mucosa was harvested at the time of TUR. Then the LV
FX concentration in these samples was measured using high-performance liqui
d chromatography. The association between drug levels, or the ratio to the
serum concentration, and factors likely to affect the vascular system that
delivers the drug (age, bodyweight, blood pressure, pulse rate, total chole
sterol and diabetes mellitus) were investigated.
Results: The mean serum drug level was 2.4 mug/mL, and it was 206.4 mug/mL
in the urine and 5.7 mug/mL in the urothelial mucosa. The mean ratio of the
mucosal to serum concentrations was 2.6. The urinary drug concentration sh
owed no association with any of the factors assessed, while the serum conce
ntration decreased with increasing bodyweight (P = 0.03). As the diastolic
blood pressure increased, both the mucosal drug concentration and the mucos
a/serum ratio decreased (P < 0.01). When the relationship between the serum
and mucosal concentrations was investigated, no correlation was found. How
ever, the mucosa/serum ratio (indicating the transfer of LVFX from the bloo
d) was positively correlated with the mucosal concentration.
Conclusion: Preoperative administration of LVFX was demonstrated to have po
tential value for the prophylaxis of UTI after TUR. Both the mucosal concen
tration and the mucosa/serum ratio were correlated with the diastolic blood
pressure. As the diastolic blood pressure seems to be an indicator of the
tissue concentration of LVFX, it may be possible to set the optimum dose ba
sed on the diastolic pressure.