Updated

U.S. health officials are recommending wider use of a new drug to treat gonorrhea because the sexually transmitted disease is steadily becoming resistant to the longtime standard antibiotic.

Fluoroquinolones, a class of antibiotics that includes Cipro, have been the most common way to treat the bacterial disease since the early 1990s. Since then, gonorrhea has grown increasingly resistant to those drugs.

On Thursday, the Centers for Disease Control and Prevention recommended that a different class of antibiotics, cephalosporins, be used instead.

"Gonorrhea has now joined the list of other superbugs for which treatment options have become dangerously few," said Dr. Henry Masur, president of the Infectious Disease Society of America. "To make a bad problem even worse, we're also seeing a decline in the development of new antibiotics to treat these infections."

The CDC made the new recommendation after discovering that nearly 7 percent of gonorrhea cases among heterosexual men in a survey of 26 U.S. cities last year had drug-resistant strains of the disease. In 2001, only about 0.6 percent of gonorrhea cases among heterosexual men were drug-resistant.

"That leaves us with a single class of highly effective antibiotics," said Dr. John Douglas Jr., director of the CDC's division of STD prevention. Other experts called the situation perilous.

It's the first time cephalosporins have been recommended to treat gonorrhea for the entire U.S. population, although the CDC recommended the antibiotics to treat against drug-resistant gonorrhea in California and Hawaii in 2002. Two years later, the CDC made the same recommendation to treat the bacterial infection among American men who have sex with men.

The newly recommended class of antibiotics includes the generic drug ceftriaxone, also known under the brand name Rocephin, which must be injected and "works very well" although the drug is not commonly stocked in doctor's offices, Douglas said.

In contrast, Cipro and other fluoroquinolones were more commonly available and easy to use because they could be taken orally in a single dose.

Ceftriaxone must be given as a shot and costs about $20, about the same as Cipro, said Ira Katz, pharmacist and owner of Little Five Points Pharmacy in Atlanta.

The CDC estimates that more than 700,000 people in the U.S. acquire gonorrhea each year through sexual contact. It is the second most commonly reported infectious disease in the United States, the infectious disease society says.

The highest rates of infection are among sexually active teens, young adults and African-Americans. Because many people don't have obvious symptoms, they can unknowingly spread it to others.

Though treatable, gonorrhea puts people at greater risk of catching the AIDS virus. In women, gonorrhea can cause pelvic inflammatory disease. In men, it can cause epididymitis, a painful condition of the testicles that can lead to infertility if untreated, the CDC said.

In the survey of 26 cities last year, Philadelphia had the highest percentage of drug-resistant cases with almost 27 percent, followed by areas in California and Hawaii where health officials long have known about gonorrhea drug resistance.

A quarter of gonorrhea cases among heterosexual men in Honolulu, San Diego and Orange County, Calif. were drug-resistant, followed by 22.5 percent of cases in San Francisco and 22 percent in Long Beach, Calif. More than 15 percent of cases in Miami were drug-resistant to the bacteria, the CDC said.