Non-Gonoccocal Urethritis (NGU) Treatment

Most cases of Non-Gonococcal Urethritis (NGU) are undiagnosed chlamydia infections. Therefore, the first line of treatment for NGU is the same as the treatment for chlamydia.

If that NGU treatment doesn’t work, and you took all your medication as instructed, your doctors 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)

If your doctor 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.

Note: The drug regimens below are taken from the Centers for Disease Control 2015 STD treatment guidelines. Remember that only your doctor can say which treatment is right for you.

One of the following treatments is typically used for initial treatment of infection:

• Azithromycin 1 g orally in a single dose
  Doxycycline 100 mg orally twice a day for 7 days

Alternative treatment regimens include one of the following:

• Erythromycin base 500 mg orally four times a day for 7 days
• Erythromycin ethylsuccinate 800 mg orally four times a day for 7 days
• Levofloxacin 500 mg orally once daily for 7 days
• Ofloxacin 300 mg orally twice a day for 7 days

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, doctors will try other options.

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.

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.