Active substances: Doxycycline
From to, the minimum concentrations of cefixime needed to inhibit the growth in vitro of N. Reports from Europe recently have described patients with uncomplicated gonorrhea infection not cured by treatment with cefixime 400 mg orally 5—8.
Each month, the first 25 gonococcal urethral isolates collected from men attending participating STD clinics approximately 6,000 isolates each year were submitted for antimicrobial susceptibility testing.
The minimum inhibitory concentration MIC, the lowest antimicrobial concentration that inhibits visible bacterial growth in the laboratory, is used to assess antimicrobial susceptibility.
Cefixime susceptibilities were not determined during — because cefixime temporarily was unavailable in the United States at that time.ShareCompartir Persons using assistive technology might not be able to fully access information in this file.
During —, 15 0. Because increasing MICs can predict the emergence of resistance, lower cephalosporin MIC breakpoints were established by GISP for surveillance purposes to provide greater sensitivity in detecting declining gonococcal susceptibility than breakpoints defined by CLSI.
In the West, the percentage increased from 0. Among MSM, the percentage increased from 0. Among 180 isolates collected during — that exhibited elevated cefixime MICs, 139 77.
Ceftriaxone as a single intramuscular injection of 250 mg provides high and sustained bactericidal levels in the blood and is highly efficacious at all anatomic sites of infection for treatment of N.
A 400-mg oral dose of cefixime does not provide bactericidal levels as high, nor as sustained as does an intramuscular 250-mg dose of ceftriaxone, and demonstrates limited efficacy for treatment of pharyngeal gonorrhea 10,11.
The significant increase in the prevalence of U.
Thus, observed patterns might indicate early stages of the development of clinically significant gonococcal resistance to cephalosporins.
CDC anticipates that rising cefixime MICs soon will result in declining effectiveness of cefixime for the treatment of urogenital gonorrhea. Furthermore, as cefixime becomes less effective, continued use of cefixime might hasten the development of resistance to ceftriaxone, a safe, well-tolerated, injectable cephalosporin and the last antimicrobial that is recommended and known to be highly effective in a single dose for treatment of gonorrhea at all anatomic sites of infection.
Maintaining effectiveness of ceftriaxone for as long as possible is critical.
Thus, CDC no longer recommends the routine use of cefixime as a first-line regimen for treatment of gonorrhea in the United States. 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.
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 among GISP isolates, particularly in strains with elevated cefixime MICs.
Recommendations For treatment of uncomplicated urogenital, anorectal, and pharyngeal gonorrhea, CDC recommends combination therapy with a single intramuscular dose of ceftriaxone 250 mg plus either a single dose of azithromycin 1 g orally or doxycycline 100 mg orally twice daily for 7 days Box.