Zithromax effective for traveler's diarrhea

By David Douglas

NEW YORK (Reuters Health) - A single-dose of the antibiotic azithromycin, sold in the U.S. under the trade name Zithromax, is recommended as the first therapy to use against traveler's diarrhea, particularly if it's acquired in Thailand, researchers report in the journal Clinical Infectious Diseases.

According to surveys of U.S. military personnel stationed in Thailand, bacteria belonging to the Campylobacter family are responsible for up to 60 percent of cases of diarrhea, Dr. David R. Tribble of the Naval Medical Research Center, Silver Spring, Maryland and colleagues note.

More than 85 percent of these pathogens are resistant to fluoroquinolone antibiotics, such as Levaquin (levofloxacin) or Cipro (ciprofloxacin), which are frequently prescribed for traveler's diarrhea.

To evaluate alternative treatments, the researchers studied 156 patients with diarrhea being treated at military field clinics in Thailand. The patients were randomly assigned to azithromycin given in a single dose or over 3 days, or to levofloxacin given for 3 days.

Campylobacter organisms were isolated in 64 percent of the patients and 50 percent of these organisms were resistant to levofloxacin. However, no azithromycin resistance was seen.

Three days after treatment was started, the cure rate was 96 percent in the single-dose azithromycin patients, 85 percent for the three-dose azithromycin patients and 71 percent for those given levofloxacin.

Eradication of bacteria up to 100 percent was seen with azithromycin compared with 38 percent with levofloxacin. Although azithromycin eradicated the bacteria much more rapidly, the time to complete recovery was about the same for each drug.

Nausea was common with the single-dose of azithromycin, but it was generally mild and transient.