SAN DIEGO — Antibiotic prophylaxis seems to prevent spontaneous bacterial peritonitis in advanced liver disease and also reduces mortality, especially in the short term, according to a report at the annual Digestive Disease Week.
Spontaneous bacterial peritonitis (SBP) develops in 10%–30% of patients with cirrhosis, and the mortality rate is 30%–50%, said Dr. Sammy Saab of the University of California, Los Angeles. The risk of recurrence is as high as 70% in 1 year, he said.
Studies of the effect of antibiotic prophylaxis on prevention and mortality have been inconclusive, Dr. Saab and his colleagues noted. Their aim was to take a broader look at the studies to better assess the effect of prophylaxis.
The researchers conducted a literature search, reviewing the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials, and Medline. They also reviewed citations in the relevant articles and abstracts from 2 decades of national meetings.
They included randomized, controlled clinical trials that compared prophylaxis with placebo or no therapy in patients with cirrhosis and ascites. In all, 65 studies were identified, but only 8 matched the inclusion criteria. The studies included 324 patients who received prophylaxis and 323 patients who were given a placebo or no intervention. In most of the studies, quinolones were used.
Prophylactic therapy reduced the risk of SBP (odds ratio, 0.61). Mortality was also reduced (OR, 0.55).
More specifically, mortality was decreased by 72% during the first 3 months. The mortality rate was 6.2% at 3 months in patients who received treatment, compared with 22% in the placebo arm. At 12 months, mortality was about 20% for those who received treatment, compared with 29% for those receiving placebo.
The overall incidence of infections was also reduced, with a relative risk of 0.32 for treated patients. Only 6.2% of patients in the treated group had infections of any type, compared with 22% of those in the placebo group.
Dr. Saab noted that the study had many limitations. A lack of complete data means that there could be undetected biases. The studies all focused on outpatients, so the authors can't draw any conclusions about inpatients and intravenous antibiotic therapy. Because most of the studies involved quinolones, the preferred antibiotic agent was not revealed. Also, bacterial resistance could be an issue with long-term therapy, but this was not addressed in the studies reviewed.
However, the data do show that oral antibiotics improve outcomes in patients with cirrhosis and ascites, Dr. Saab noted.