September 23, 2005
A single oral dose of the antibiotic azithromycin is just as effective as penicillin injections in treating syphilis, according to a Tanzania-based study in Thursday's New England Journal of Medicine.
An injection of penicillin has long been the recommended treatment for syphilis. But in poor countries where there is often a shortage of sterile needles and trained physicians to administer the injections, azithromycin might be a viable alternative, Dr. Gabriele Riedner of the London School of Hygiene and Tropical Medicine and colleagues reported.
In Mbeya, Tanzania, 328 syphilis patients received either an azithromycin pill or a shot of penicillin and were followed up every three months for up to nine months. In both groups, the cure rate was similar: 98 percent in the azithromycin group compared to 95 percent in the penicillin group.
Penicillin is likely to remain the treatment standard in the United States because of its effectiveness. Last year, researchers detected a syphilis strain resistant to azithromycin. Riedner noted that there is no evidence that an antibiotic-resistant strain is widespread in Tanzania.
Azithromycin treatment is also being studied in four US cities and in Madagascar.
The full study, "Single-Dose Azithromycin Versus Penicillin G Benzathine for the Treatment of Early Syphilis," and an accompanying editorial, "Azithromycin Versus Penicillin G Benzathine for Early Syphilis," were published in the New England Journal of Medicine (2005;353(12):1236-1244 and 1291-1293, respectively).