Non-Gonoccocal Urethritis (NGU) Treatment

Urethritis is inflammation of the urethra - normally caused by infection. Non-gonococcal urethritis (NGU) refers to cases that are not caused by gonorrhea - a sexually transmitted infection.

Although there are several causes of NGU, the most common is chlamydia, another sexually transmitted infection. Often, cases of NGU go undiagnosed and people receive the same treatment for chlamydia.

Learn more about treatments you could expect to receive for NGU, which are based on the most recent treatment guidelines for sexually transmitted infections from the U.S. Centers for Disease Control and Prevention.

Initial Treatment

Because NGU goes undiagnosed, people with the infection likely receive the recommended treatment for chlamydia instead. For adults with chlamydia, one of the following treatments is typically used for initial treatment of the infection:

• Doxycycline 100 mg orally twice a day for 7 days
• Azithromycin 1 g orally in a single dose (this is considered an alternative)

Other treatment options may be used for other populations, including infants, children and people who are pregnant.

Sometimes these treatments are ineffective. That is often because the infection is caused by a fungal or parasitic infection, such as trichomoniasis. (Sometimes the parasitic infection is in addition to a bacterial infection!) Therefore, if the initial treatment fails, healthcare providers will try other options.

If that NGU treatment doesn’t work, and you took all your medication as instructed, your healthcare providers need to investigate further. The next step is usually for them to check you for a trichomoniasis infection. If that test is negative, you may not get a clear answer. (Often NGU is caused by mycoplasma, but that is only rarely tested for.

When Initial Treatment Isn't Successful

If your healthcare provider can’t identify what the source of the infection is, they will generally treat you with one of the drugs below. This is because some of the bacteria that cause urethritis can be difficult to identify. Therefore, treating NGU this way is an effective way to eliminate the most common suspects.

One of the following medications can be used if initial treatment is not successful:

• Metronidazole 2 g orally in a single dose
• Tinidazole 2 g orally in a single dose
• Azithromycin 1 g orally in a single dose (if not used for initial treatment)
• Moxifloxacin 400 mg orally once daily for 7 days (if azithromycin was used for initial treatment)

The azithromycin and moxifloxacin are used because they are more likely to be effective against mycoplasma than some other medications. The moxifloxacin, in particular, is a relatively new recommendation. By the time the 2015 treatment recommendations were released, mycoplasma were considered to be a major cause of NGU. Therefore, aiming treatment at mycoplasma was thought to be important after an initial treatment failure. However, the CDC has found that higher dose azithromycin is not helpful in treating mycoplasma. That's why they recommend moxifloxacin rather than a second round of azithromycin treatment for NGU.

In contrast, metronidazole and tinidazole are used to treat possible trichomoniasis infections. Testing is not universally available for this infection in men.

Additional Treatment Notes

You should generally stop having sex while on treatment. This reduces the likelihood that you and your partner will pass an infection back and forth. Any regular sexual partner should also be referred for testing and treatment when you are diagnosed with an STD.