Antibiotic Pill Can Treat Early Syphilis

Study: A Single Azithromycin Pill Works as Well as 1 Penicillin Shot

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Sept. 21, 2005 -- The early stages of syphilis can be treated effectively with a single pill instead of a shot, new research shows.

Scientists found that a single, 2-gram pill of the antibiotic azithromycin worked as well as one shot of penicillin at treating early syphilis.

The finding could help treat syphilis in developing countries with limited health care resources, write Gabriele Riedner, MD, PhD, and colleagues in The New England Journal of Medicine.

Riedner works at the London School of Hygiene and Tropical Medicine.

However, an editorial in the journal voices caution about changing syphilis treatment.

About Syphilis

Syphilis is a sexually transmitted disease. Pregnant women can also pass syphilis to their fetus, which can be fatal for the baby.

Syphilis has four stages with these symptoms:

  • Primary stage: Sores (called chancres) appear on the part of the body exposed to the infected partner's ulcer; it may be inside the body and not noticed. It disappears whether or not a person gets treated.
  • Secondary stage: Rash appears, which also will disappear without treatment. Yet the sores contain active bacteria; broken skin of an infected person may spread the infection by sexual or nonsexual contact. Other symptoms may include swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue.
  • Latent stage: Syphilis lies low. Symptoms disappear and the disease isn't contagious in this stage.
  • Late stage: Bacteria damage the body on the inside. Virtually any part of the body may be affected, including the brain, heart, eyes, nerves, joints, and bones. This stage may last for years or even decades and can lead to mental illness, blindness, heart disease, neurological problems, and death.

Syphilis Rare in the U.S.

U.S. syphilis rates in 2000 were the lowest since the government started keeping track in 1941.

However, syphilis rates were up slightly in 2002 and 2003. Those increases were only seen among men, reports the CDC.

In 2003, the CDC got reports of 7,177 cases of primary and secondary syphilis. That's up 4.6% from 2002, according to the CDC.

A government plan to wipe out syphilis was launched in 1999. Progress has been made but "syphilis remains an important problem in the South and in some urban areas in other regions of the country," states the CDC's web site.

For instance, Minnesota's health department reported that syphilis cases among gay and bisexual men dropped in 2004 but rose during the first half of 2005.

Minnesota had 43 reported cases of early syphilis among gay or bisexual men as of June 1, 2005. That's up from 18 cases during the first half of 2004, states a Minnesota health alert.

Syphilis Study

The new syphilis treatment study was done in Mbeya, Tanzania. It included 25 adults with primary syphilis and 303 with latent syphilis.

The patients were 27 years old, on average. They were patients at a sexually transmitted infection clinic, traditional brew sellers, or women who worked in bars. None of the women were pregnant.

About half of the patients were also HIV positive (52%). Syphilis can make someone three to five times more likely to get and spread HIV, the virus that causes AIDS, according to the National Institute of Allergy and Infectious Diseases.

Patients either got a single azithromycin pill or a shot of penicillin. They were followed for nine months, though some were late for scheduled checkups.

There was "clear evidence" that the pill and shot worked equally well for treating early syphilis, write the researchers.

The drug company Pfizer donated the pills but had no other involvement in the study, the researchers note. Pfizer is a WebMD sponsor.

Antibiotic Resistance?

There have been reports of azithromycin resistance in the bacteria that causes syphilis.

No such resistance was seen in this study, but it's important to monitor azithromycin resistance, note the researchers.

Possible resistance is a reason to be "cautious" about using azithromycin to treat early syphilis, writes King Holmes, MD, PhD, in a journal editorial.

Holmes urges close follow-up of any patients -- anywhere in the world -- who are treated with azithromycin for early syphilis.

The penicillin shots still work, notes Holmes. He works at the University of Washington's department of medicine and Center for AIDS and Sexually Transmitted Diseases.

WebMD Health News


SOURCES: Riedner, G. The New England Journal of Medicine, Sept. 22, 2005; vol 353: pp 1236-1244. National Institute of Allergy and Infectious Diseases: "Syphilis." CDC, "STD Surveillance Profile 2003: Syphilis." Minnesota Department of Public Health, "Alert for Health Providers -- Gay and Bisexual Men: Monitoring for LGV; Syphilis and Quinolone-Resistant Gonorrhea Increasing." Holmes, K. The New England Journal of Medicine, Sept. 22, 2005; vol 353: pp 1291-1293.
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