What is the diagnosis and treatment for non-gonococcal urethritis (NGU)?

From the Guidelines

Non-gonococcal urethritis should be treated with doxycycline 100 mg orally twice daily for 7 days as the first-line treatment, as recommended by the most recent guidelines 1. The treatment of non-gonococcal urethritis (NGU) has evolved over time, with the most recent guidelines providing the best approach to management.

Key Considerations

• The European Association of Urology guidelines from 2024 provide the most up-to-date recommendations for the treatment of NGU 1.
• The guidelines recommend doxycycline 100 mg orally twice daily for 7 days as the first-line treatment for NGU.
• Alternative treatments include azithromycin 500 mg orally on day 1, followed by 250 mg orally for 4 days, which can be used in patients who cannot take doxycycline.
• The most common causes of NGU are Chlamydia trachomatis, Mycoplasma genitalium, Ureaplasma urealyticum, and Trichomonas vaginalis.

Treatment Approach

• Patients with NGU should be treated as soon as possible after diagnosis to prevent complications and reduce the risk of transmission to sexual partners.
• Sexual partners from the past 60 days should be evaluated and treated to prevent reinfection.
• Patients should abstain from sexual activity until they and their partners have completed treatment and symptoms have resolved.
• Persistent or recurrent NGU may require testing for Mycoplasma genitalium and treatment with moxifloxacin 400 mg daily for 7-14 days.

Diagnosis

• NGU is diagnosed through a combination of clinical symptoms and laboratory tests showing urethral inflammation with white blood cells in urethral discharge, while ruling out gonorrhea through nucleic acid amplification testing.
• The diagnosis of NGU should be based on the presence of symptoms such as urethral discharge, dysuria, and urethral itching or discomfort, as well as laboratory evidence of urethral inflammation.

Key Points to Consider

• The treatment of NGU should be guided by the most recent guidelines and should take into account the patient's medical history, allergy status, and potential resistance patterns.
• Patients with NGU should be educated on the importance of completing treatment, abstaining from sexual activity until symptoms have resolved, and notifying sexual partners.
• The management of NGU requires a comprehensive approach that includes diagnosis, treatment, and prevention of complications and transmission.

From the FDA Drug Label

Nongonococcal urethritis (NGU) caused by C. trachomatis or U. urealyticum: 100 mg, by mouth, twice a day for 7 days. The recommended dose of doxycycline for the treatment of non-gonococcal urethritis is 100 mg, twice a day for 7 days 2.

• The treatment is effective against C. trachomatis and U. urealyticum.
• It is essential to note that doxycycline is not the only treatment option, and other antibiotics like azithromycin may also be used 3.

From the Research

Causes of Non-Gonococcal Urethritis

• Non-gonococcal urethritis (NGU) is caused by various microorganisms, including Chlamydia trachomatis, Mycoplasma genitalium, Ureaplasma urealyticum, Trichomonas vaginalis, anaerobes, Herpes simplex virus (HSV), and adenovirus 4
• Approximately 20-50% of NGU cases are due to Chlamydia trachomatis, while 10-30% are caused by Mycoplasma genitalium 4

Diagnosis of Non-Gonococcal Urethritis

• The diagnosis of NGU is confirmed by demonstrating an excess of polymorphonuclear leucocytes (PMNLs) in a stained smear 4
• Nucleic acid amplification tests (NAAT) for Neisseria gonorrhoeae, C. trachomatis, and M. genitalium are recommended for patients presenting with symptoms of urethritis 4
• If viral or protozoan etiology is suspected, NAAT for HSV, adenovirus, and T. vaginalis may be performed 4

Treatment of Non-Gonococcal Urethritis

• Treatment options for NGU include doxycycline 100 mg twice daily for one week, azithromycin 1 gram single dose, or azithromycin 1.5 gram distributed over five days 4
• Azithromycin has been shown to be effective in treating NGU, with clinical cure rates comparable to doxycycline 5, 6, 7
• However, the use of azithromycin as first-line treatment without testing for M. genitalium and subsequent moxifloxacin treatment of macrolide-resistant strains may select for and increase macrolide-resistant strains in the population 4
• The 2016 European guideline recommends doxycycline 100 mg twice daily for seven days as first-line therapy, with azithromycin 1 gram no longer recommended due to concerns about antimicrobial resistance in M. genitalium 8

Management of Persistent or Recurrent Non-Gonococcal Urethritis

• Persistent or recurrent NGU must be confirmed with microscopy, and reinfection and compliance should be considered 4
• If doxycycline was given as first therapy, azithromycin five days plus metronidazole may be given, while if azithromycin was prescribed as first therapy, doxycycline 100 mg twice daily for one week plus metronidazole or moxifloxacin 400 mg orally once daily for 7-14 days may be given 4