Effect of fluoroquinolone on the enhanced nitric oxide-induced peripheral vasodilation seen in cirrhosis

Ann Intern Med. 1997 Dec 1;127(11):985-8. doi: 10.7326/0003-4819-127-11-199712010-00007.


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.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / therapeutic use*
  • Cross-Over Studies
  • Double-Blind Method
  • Endotoxemia / drug therapy*
  • Endotoxemia / metabolism
  • Endotoxemia / physiopathology
  • Forearm / blood supply
  • Humans
  • Liver Cirrhosis, Alcoholic / microbiology*
  • Middle Aged
  • Nitric Oxide / biosynthesis*
  • Nitric Oxide / physiology
  • Norfloxacin / therapeutic use*
  • Regional Blood Flow / drug effects
  • Vasodilation / drug effects*


  • Anti-Infective Agents
  • Nitric Oxide
  • Norfloxacin