Loperamide plus azithromycin more effectively treats travelers' diarrhea in Mexico than azithromycin alone.
BACKGROUND
Because the combination of loperamide and some antimicrobials has proven to be more efficacious than the antimicrobial agent alone in the treatment of travelers' diarrhea, we set out to prove loperamide plus azithromycin was more efficacious than azithromycin alone.


METHODS
During the summers of 2002 to 2003, 176 US adults recently arrived in Guadalajara, Mexico were enrolled in a prospective, double-blinded, randomized trial of the treatment of acute diarrhea. Subjects received single doses (1,000 or 500 mg) of azithromycin or a single 500 mg dose of azithromycin plus loperamide. Subjects gave a pre- and post-treatment stool sample for analysis and maintained daily diaries of symptoms and passage of stools.


RESULTS
The duration of diarrhea was significantly (p=0.0002) shorter following treatment with azithromycin plus loperamide (11 h) than with either dose of azithromycin alone (34 h). In the first 24 hours, the average number of unformed stools passed was 3.4 (azithromycin alone) and 1.2 (combination) for a significant (p<0.0001) difference of 2.2 unformed stools. This difference equated with 20% of azithromycin-treated subjects continuing to pass six or more unformed stools in the first 24 hours post-treatment compared with only 1.7% of combination-treated subjects.


CONCLUSIONS
For the treatment of travelers' diarrhea in an Escherichia coli predominant region of the world, a single 500 mg dose of azithromycin appeared as effective as a 1,000 mg dose. Loperamide plus 500 mg of azithromycin was safe and more effective than either dose of azithromycin. To realize the substantial clinical benefit that accrues to a subset of subjects, we feel loperamide should routinely be used in combination with an antimicrobial agent to treat travelers' diarrhea.
Ericsson
Charles D
CD
Department of Medicine, Division of Infectious Diseases, University of Texas Medical School at Houston, and St Luke's Episcopal Hospital, Houston, TX 77030, USA. charles.d.ericsson@uth.tmc.edu
DuPont
Herbert L
HL
Okhuysen
Pablo C
PC
Jiang
Zhi-Dong
ZD
DuPont
Margaret W
MW
D000208:Acute Disease; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D000930:Antidiarrheals / Q000008:administration & dosage*; D017963:Azithromycin / Q000008:administration & dosage*; D003967:Diarrhea / Q000188:drug therapy*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008139:Loperamide / Q000008:administration & dosage*; D008297:Male; D008800:Mexico; D008875:Middle Aged; D018570:Risk Assessment; D014195:Travel; D016896:Treatment Outcome; D014481:United States
D000900:Anti-Bacterial Agents; D000930:Antidiarrheals; D008139:Loperamide; D017963:Azithromycin