Objective: To evaluate the safety and efficacy of domestic intravenous doxycycline in the treatment of urinary tract infections.Methods:A multicenter

double-blind

randomized controlled clinical trial of intravenous doxycycline and azithromycin on patients with urinary tract infections were conducted.The dosage of doxycycline was 0.2g

once daily

for 5~12d and that of azithromycin was 0.5g

once daily

for 5~12d.Both drugs were given intravenously.Results: In this trial

62 patients were enrolled in doxycycline group

and 60 were enrolled in azithromycin group.The overall efficacy rates and cure rate in trial and control group were 100%

90.32% and 73.33%

95% respectively.There was statistical significant difference in the cure rates between the two groups.The bacterial clearance rates in two groups were 92.5% and 88.9% respectively.The adverse drug reaction rates were7.9% and6.7% respectively.There were no statistical significant differences in the above results between the two groups.The activity of doxycycline against gram-positive organisms was generally higher than that of the other 5 antibacterial agents.Antibacterial activity of doxycycline against gram-negtive bacterium was similar to or stronger than the other antibacterial agents.Conclusion: The results suggest that domestic doxycycline injection with powerful antibacterial activity and wide spectrum is highly effective in treating urinary tract infections.