2020 US CDC updated the treatment of simple gonococcal infections

2020 US CDC updated the treatment of simple gonococcal infections. 2020 U.S. CDC’s updated interpretation of guidelines for the treatment of simple gonococcal infections.

Gonorrhoea is a sexually transmitted disease (STD) caused by Neisseria gonorrhoeae (NG) infection. As the second most common bacterial STD, it seriously endangers human reproductive health. The US CDC’s STD treatment guidelines will be updated regularly to standardize the diagnosis and treatment of gonorrhea. In recent years, the incidence of gonorrhoea and the resistance to antibacterial drugs have increased significantly. Therefore, in 2020, the relevant guidelines have been updated again to replace the previous 2015 version.

1. History of changes recommended by previous guidelines

Since 1985, it has been recommended to use a highly effective drug to treat NG that can simultaneously be effective against chlamydia.

In view of the widespread spread of quinolone-resistant NG in the United States, since 2007, the CDC has no longer recommended the use of quinolone drugs, and only cephalosporin is the only recommended drug.

In order to reflect concerns about emerging NG resistance, the 2010 CDC recommended the use of combined cephalosporin (ceftriaxone 250 mg, IM or cefixime 400 mg, oral) and azithromycin or doxycycline dual treatment for NG.

Due to the gradual emergence of cefixime resistance, the CDC no longer recommended cefixime for the treatment of NG in 2012. Therefore, ceftriaxone combined with azithromycin has become the only recommended treatment for simple gonorrhea.

2. Update of existing main evidence

Since the release of the CDC Guidelines for the Treatment of Sexually Transmitted Diseases in 2015, people have paid more and more attention to the management of antibacterial drugs, especially the impact of antibacterial drugs on the microbiome. The development of pharmacokinetic and pharmacodynamic models also affects the understanding of the best antibacterial drugs for NG.

(1) The rationality of dual therapy with ceftriaxone and azithromycin needs to be reassessed. There is evidence that oral azithromycin may affect the therapeutic effects of other antibacterial drugs, and the resistance of azithromycin such as mycoplasma has gradually increased. Therefore, although the dual-drug therapy of ceftriaxone combined with azithromycin may alleviate the development of NG resistance to ceftriaxone, it is necessary to fully consider its potential impact on other microorganisms.

(2) According to the calculation of pharmacokinetic and pharmacodynamic models, 250 mg of ceftriaxone sodium cannot reliably reach the effective therapeutic dose level higher than MIC ≥ 0.125 μg/mL in a long time.

(3) The importance of pharynx NG treatment. Compared with other anatomical sites, the frequency of screening for NG in the pharynx is lower, and worldwide, most of the failures of treatment based on ceftriaxone regimens involve pharyngeal gonorrhoea. There is evidence that the treatment of pharyngeal NG may require a longer duration of action.

(4) The resistance of NG to azithromycin is gradually increasing. Although the mechanism of drug resistance is multifaceted, azithromycin exposure is one of the reasons.

3. The latest recommendations of the guide

In view of the above evidence, the main update of the 2020 guidelines is to recommend higher doses of ceftriaxone (500 mg) and remove azithromycin from the recommended treatment regimen. The detailed recommendations are as follows:

(1) Treatment plan for simple cervix, urethra and rectal NG infections

A single intramuscular injection of ceftriaxone 500 mg is recommended (suitable for those with a body weight of <150 kg).

For those weighing ≥ 150 kg, a single intramuscular injection of ceftriaxone 1 g should be used.

If chlamydia infection cannot be ruled out, doxycycline should be taken orally at the same time, 100 mg/time, 2/day for 7 days. During pregnancy, it is recommended to use azithromycin 1 g as a single oral treatment for chlamydia.

(2) Alternative treatment plan for simple cervical, urethral and rectal NG infections without ceftriaxone

A single intramuscular injection of 240 mg of gentamicin is recommended, and a single oral dose of 2 g of azithromycin.

Or a single oral cefixime 800 mg. If chlamydia infection cannot be ruled out during treatment with cefixime, doxycycline should be taken orally at the same time, 100 mg/time, 2/day for 7 days. During pregnancy, it is recommended to use azithromycin 1 g as a single oral treatment for chlamydia.

(3) Treatment plan for simple pharyngeal NG infection

Recommend a single intramuscular injection of ceftriaxone 500 mg (suitable for those with a body weight of <150 kg)

For those weighing ≥ 150 kg, a single intramuscular injection of ceftriaxone 1 g should be used.

If a combined chlamydia infection is found during the NG test of the pharynx, doxycycline should be taken orally at the same time, 100 mg/time, 2/day for 7 days. During pregnancy, it is recommended to use azithromycin 1 g as a single oral treatment for chlamydia.

There is no reliable alternative for pharyngeal gonorrhea. For those with a history of β-lactam allergy, a thorough reactivity assessment is recommended.

Those who have allergies or other severe reactions to ceftriaxone are advised to consult an infectious disease specialist for alternative treatment.

In addition, it should be noted: (1) Treatment of sexual partners. If permitted by law, and the sexual partner cannot or cannot seek prompt treatment. When chlamydia infection is ruled out, it is recommended that sex partners take cefixime 800 mg orally; otherwise, it is recommended to take doxycycline at the same time, 100 mg/time, 2/day for 7 days. (2) If it is suspected that the cephalosporin treatment has failed, NG culture and drug sensitivity test should be carried out, and the CDC should be reported in time. (3) For patients with simple genitourinary tract or rectal gonorrhoea, no cure test is required after treatment. However, for patients with pharyngeal gonorrhea, a cure test is recommended 7-14 days after the initial treatment. (4) In view of the risk of reinfection, it is recommended that patients with gonorrhea undergo retesting 3 months after treatment; if retesting cannot be performed on time, it is recommended that retesting be performed within 12 months after initial treatment. (5) Drug resistance is an important reason that affects the change of NG treatment plan. Therefore, it is necessary to continue to monitor the therapeutic effect and drug resistance of ceftriaxone in NG.

In summary, based on the increased understanding of pharynx NG infection and the increase in NG resistance to azithromycin, the main update of the 2020 CDC guidelines for the treatment of simple NG infections is to recommend higher doses of ceftriaxone (500 mg) And remove azithromycin from the recommended treatment regimen. Antibiotic resistance is the main factor affecting NG treatment. Therefore, when using this guideline for reference, comprehensive consideration should be given to the NG resistance situation in the region.

(source:internet, reference only)

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