A single dose of the antibiotic azithromycin, sold in the US Under the trade name Zithromax, is recommended as the first therapy to be used against traveler’s diarrhea, especially if acquired in Thailand, researchers report in the journal Clinical Infectious Diseases.
According to surveys of US military personnel stationed in Thailand, bacteria belonging to the Campylobacter family account for up to 60 percent of cases of diarrhea, said Dr. David R. Tribble of the Naval Medical Research Center in Silver Spring, Maryland .
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, researchers studied 156 patients with diarrhea who were being treated at military field clinics in Thailand. Patients were randomized to azithromycin given as a single dose or for 3 days, or to levofloxacin given for 3 days.
Campylobacter organisms were isolated in 64 percent of patients and 50 percent of these organisms were resistant to levofloxacin. However, no resistance to azithromycin was observed.
Three days after initiation of treatment, the cure rate was 96 percent in azithromycin single dose patients, 85 percent in patients with azithromycin at three doses, and 71 percent in patients receiving levofloxacin.
Eradication of bacteria up to 100 percent with azithromycin was observed compared to 38 percent with levofloxacin. Although azithromycin eradicated the bacterium much more rapidly, the time to complete recovery was approximately the same for each drug.
Nausea was common with the single dose of azithromycin, but was generally mild and transient.
Researchers recommend a single dose of azithromycin for travelers’ diarrhea acquired in Thailand when the pathogen causing the infection is not known and is a good initial treatment overall.
Dr. Herbert L. DuPont, author of an accompanying editorial, told Reuters Health that “people destined for a developing country should have with them a drug for the self-treatment of common diarrhea that occurs.”
“No drug works for all forms of this disease,” added DuPont of Baylor College of Medicine, Houston, Texas. However, “azithromycin has an advantage during the trip to Asia as it addresses the most invasive causes of diarrhea leading to fever and dysentery.”