Mycoplasma genitalium treatment guidelines

NAAT

Nucleic acid amplification test

First pass urine (FPU)

Urethral swab

Anorectal swab

Most labs offer NAAT testing for MG, and some NAATs also detect mutations conferring resistance to azithromycin to assist in individualising therapy.

A FPU specimen is more sensitive than a urethral swab.

Throat swabs are unnecessary as pharyngeal infection is rare

NAAT

Vaginal swab

Cervical swab

FPU

A vaginal swab is the most sensitive specimen followed by cervical swab then urine

Women who present with cervicitis, PID or post coital bleeding should be tested for MG.

For MG known or suspected to be macrolide-susceptible:

Doxycycline 100mg PO, twice daily for 7 days,followed immediately by Azithromycin 1g PO, stat, then 500mg daily for another 3 days (2.5g total)

For MG known or suspected to be macrolide resistant:

Doxycycline 100mg PO, twice daily for 7 days, followed immediately by Moxifloxacin 400mg PO daily for 7 days

Macrolide resistance mutations are detected in approximately 80% of MSM and 50% of heterosexual men and women infected with MG at Melbourne Sexual Health Centre (MSHC).

Infections susceptible to azithromycin develop detectable de novo resistance in 12% of cases treated with azithromycin.

To improve treatment efficacy and reduce selection of resistance MSHC developed a sequenced resistance-guided treatment strategy based on the macrolide-resistance profile of M. genitalium.

Moxifloxacin is not approved by the Therapeutic Goods Administration (TGA) for this infection and may cause significant side-effects including diarrhoea or tendonitis. We recommend discussing this with patients and assessing for contraindications and drug interactions. Pharmacies typically charge over $70 for five tablets. There are limited efficacy data and no data for treatment courses of less than 7 days.
MG already treated with azithromycin on the same day as they were tested may be cured but confirm this with a test of cure 2-3 weeks later. If treatment fails, resistance is likely, particularly if reinfection is unlikely. Clinicians with no access to resistance testing can assume resistance in azithromycin treatment failures.

Azithromycin 1g PO, stat, then 500mg daily for another 3 days (2.5g total)

OR

Pristinamycin 1g PO, 4 times a day for 10 days

1) Minocycline 100 mg PO twice daily for 14 days

OR if available

2) Pristinamycin 1g PO, 3 times a day for 10 days combined with

Doxycycline 100 mg PO, twice daily for 10 days

OR if available

3) Sitafloxacin 100 mg PO, twice daily for 7 days combined with

Doxycycline 100 mg PO, twice daily for 7 days

Resistance to moxifloxacin was detected in 15-20% of infections in Melbourne in 2016-18 and so moxifloxacin treatment-failures are not uncommon.

Minocycline cures 70% of macrolide-resistant infections. Minocycline is available on private script and is therefore a practical option for patients with macrolide-resistant MG who have failed moxifloxacin in the community.

Both pristinamycin and sitafloxacin have been subject to export bans in their country of manufacture so their availability is very limited in Australia. However if available:

Pristinamycin has been used at MSHC at a dose of 1g three times daily combined with doxycycline 100mg bd for 10 days and cures 75% of macrolide-resistant infections. Pristinamycin is available through hospital pharmacies, using the Special Access Scheme of the TGA and can be used in pregnancy. For patients with macrolide-resistant MG in whom doxycycline is contraindicated, prescribe pristinamycin 1g four times daily for ten days.

Sitafloxacin in combination with doxycycline has proven effective at MSHC and cures >90% of patients in a published series of patients with highly resistant MG. Access to this medication is limited and requires TGA approval (completion of a Category B TGA form). This option is limited to specialised services so consult with a sexual health physician if no other options are available. A test of cure 2- 3 weeks after completing therapy is essential.