Spiramycin, a macrolide antibiotic, has been studied in the United States for the treatment of cryptosporidial diarrhea. Some reports suggest that spiramycin is useful in improving the symptoms of cryptosporidial diarrhea in some patients. Results of one study, however, showed no significant difference between spiramycin and placebo (inactive medication). A later study indicated that the absorption of spiramycin is significantly decreased when food is present. Thus, the results of the trial may have been due to poor absorption of spiramycin.