Untreatable gonorrhea soon could be a reality in the United States, according to an August 10 CDC update in Morbidity and Mortality Weekly Report(www.cdc.gov) (MMWR). The agency notes that Neisseria gonorrhoeae seems to be developing a resistance to the oral antibiotic cefixime, and it is asking physicians to stop using the drug when possible.
This photograph shows a newborn with gonococcal ophthalmia neonatorum caused by a maternally transmitted gonococcal infection. If Neisseria gonorrhoeae develops total antimicrobial resistance, such cases could show up in the United States.
A news release(www.cdc.gov) from the CDC, says that recent trends in laboratory data indicate cefixime is becoming less effective in treating gonoccocal infection. With that in mind, the CDC updated its 2010 STD guidelines and now favors injectable therapy in combination with a second antibiotic in an attempt to slow the increasing prevalence of antimicrobial-resistant bacteria.
"CDC recommends combination therapy with ceftriaxone 250 mg intramuscularly and either azithromycin 1 g orally as a single dose or doxycycline 100 mg orally twice daily for seven days as the most reliably effective treatment for uncomplicated gonorrhea," according to the MMWR report. "CDC no longer recommends cefixime at any dose as a first-line regimen for treatment of gonococcal infections."
There are times, however, when cefixime may be the best available option, says the report's lead author and CDC Officer Robert Kirkcaldy, M.D., M.P.H. in a commentary(www.medscape.com) (free registration is required) in Medscape Today.
- In light of recent data suggesting that Neisseria gonorrhoeae is developing resistance to the oral antibiotic cefixime, the CDC has updated its 2010 STD guidelines.
- The agency's guidance now recommends that physicians stop using cefixime to treat gonorrhea and instead use combination therapy with ceftriaxone, 250 mg intramuscularly, and either azithromycin, 1 g orally as a single dose, or doxycycline, 100 mg orally twice daily for seven days.
- The switch may delay emergence and spread of resistance to cephalosporins.
"In instances where ceftriaxone is not available, CDC recommends cefixime 400 mg orally, plus either azithromycin 1 g orally or doxycycline 100 mg orally twice daily for seven days," Kirkcaldy says. "For patients with a severe allergy to cephalosporins, CDC recommends a single 2-g dose of azithromycin orally. In both of these circumstances, CDC recommends a test of cure for these patients one week after treatment."
The CDC also is asking physicians to monitor patients for treatment failure and report any suspected failures.
"Patients who have persistent symptoms after treatment should be retested by culture," Kirkcaldy says. "If these cultures are positive for the gonococcus, isolates should be submitted for resistance testing.
"A test of cure should be conducted one week after retreatment. Providers should also ensure that the patient's sex partners from the preceding 60 days are promptly evaluated and treated."
The second most commonly reported notifiable infection in the United States, gonorrhea is a major cause of pelvic inflammatory disease, ectopic pregnancy and infertility in women. It also can facilitate HIV transmission. The efficacy of fluoroquinolones for gonorrhea waned more than a decade ago, so cephalosporins, such as cefixime and ceftriaxone, have served as the only remaining antimicrobial class to treat the disease. But according to the new reports, the clock is now ticking on this class as well.
"From 2006 to 2010, the minimum concentrations of cefixime needed to inhibit the growth in vitro of N. gonorrhoeae strains circulating in the United States and many other countries increased, suggesting that the effectiveness of cefixime might be waning," says the CDC report. "Based on experience with other microbes that have developed antimicrobial resistance rapidly, a theoretical basis exists for combination therapy using two antimicrobials with different mechanisms of action to improve treatment efficacy and potentially delay emergence and spread of resistance to cephalosporins.
"Therefore, the use of a second antimicrobial … is recommended for administration with ceftriaxone. The use of azithromycin as the second antimicrobial is preferred to doxycycline because of the convenience and compliance advantages of single-dose therapy and the substantially higher prevalence of gonococcal resistance to tetracycline than to azithromycin."
The AAFP recommends that clinicians screen all sexually active women, including those who are pregnant, for gonorrhea infection if they are at increased risk for infection. The Academy's complete list of screening recommendations for gonorrhea can be found online.