We conducted a prospective controlled study on 150 patients with steri
le urine undergoing ESWL treatment for renal and ureteric stones to ev
aluate the value of a single dose of antibiotic prophylaxis. The patie
nts were placed randomly in three groups with 50 patients in each grou
p. A single dose of i.v. 1.2 g co-amoxiclav was given to patients in G
roup A, 80 mg gentamicin to Group B and isotonic saline was given to G
roup C as a control, at the beginning of ESWL treatment. Urine culture
s after ESWL were obtained at 24 h and 1 week, five patients in group
A (10%); six patients in Group B (12%) and five patients (10%) in the
control group had positive urine cultures after ESWL. The methodology,
results and conclusions drawn from this study are presented.