Norfloxacin therapy for hepatopulmonary syndrome: a pilot randomized controlled trial

The hepatopulmonary syndrome occurs in up to one-third of patients with cirrhosis. Animal models of this disease suggest that endotoxemia might cause nitric oxide-mediated vascular dilatation that can be inhibited by the antibiotic norfloxacin. We sought to test this hypothesis in humans.

We conducted a pilot randomized, controlled crossover trial of norfloxacin 400 mg twice daily for 4 weeks with a 4-week washout period to assess the feasibility of a larger trial. The primary clinical end point was change in alveolar-arterial oxygen gradient (AaDO₂).

Recruitment was challenging, and change in AaDO₂ was highly variable. We recruited 9 adults (1 woman; age, 60 ± 9 years; AaDO₂, 50 ± 22 mm Hg). AaDO₂ decreased by 0.8 ± 4.8 and 3.4 ± 12.4 mm Hg while on norfloxacin and placebo, respectively (P = .59).

Recruitment difficulties and variability of the primary outcome measure suggest the need for a multicenter clinical research network for future therapeutic trials in this disease. There was no major effect of norfloxacin on gas exchange in patients with hepatopulmonary syndrome.