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Updated: May 4, 2026

Ultrasound Assessment of Endothelial-Dependent Flow-Mediated Vasodilation of the Brachial Artery in Clinical Research
Published on: October 22, 2014
Effect of fluoroquinolone on the enhanced nitric oxide-induced peripheral vasodilation seen in cirrhosis
J P Chin-Dusting1, B Rasaratnam, G L Jennings
1Alfred and Baker Medical Unit, Baker Medical Research Institute, Victoria, Australia.
Background:
In patients with cirrhosis, portosystemic shunts allow intestinal bacteria and endotoxin to enter the systemic circulation. Endotoxemia may induce increased synthesis of nitric oxide, thereby contributing to arterial vasodilation.
Objective:
To test the hypothesis that the antibiotic norfloxacin blocks the effects of nitric oxide.
Design:
Placebo-controlled, double-blind, crossover study.
Setting:
Alfred Hospital, Melbourne, Australia.
Patients:
9 patients with alcohol-related cirrhosis and 10 healthy controls.
Intervention:
Norfloxacin, 400 mg twice daily, for 4 weeks.
Measurements:
Peripheral blood flow was measured by using forearm venous occlusion plethysmography.
Results:
Basal forearm blood flow was higher in patients with cirrhosis than in controls (3.69 +/- 0.27 mL/100 mL per minute and 2.47 +/- 0.40 mL/100 mL per minute; P = 0.014) but returned toward normal after norfloxacin was given (2.64 +/- 0.31 mL/100 mL of tissue per minute in patients with cirrhosis). Responses to NG-monomethyl-L-arginine were greater in patients with cirrhosis but returned to normal after norfloxacin was given.
Conclusion:
Bacterial endotoxemia in patients with cirrhosis induces increased synthesis of nitric oxide that can be corrected with norfloxacin.
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