An oral antibiotic tablet used to treat common eye infections could be used as a treatment for the sexually transmitted disease Mycoplasma genitalium, according to new research.
According to researchers, Mycoplasma genitalium has become resistant to the usually recommended treatments. However, chloramphenicol, an antibiotic used to treat conjunctivitis, was found to clear up a singular patient’s Mycoplasma genitalium.
Researchers from the Chelsea and Westminster Hospital NHS Foundation Trust have suggested in the journal Sexually Transmitted Infections that the antibiotic could be used as a future treatment for Mycoplasma genitalium.
Treatment options for Mycoplasma genitalium are running low
According to data from the UK Health Security Agency, due to increased antimicrobial resistance the first and second-choice treatment options for Mycoplasma genitalium no longer work. Currently, there is no strong evidence supporting a third treatment option.
In their study, the researchers describe the case of a young man with recurrent non-gonococcal urethritis symptoms, a common sexually transmitted infection caused by Mycoplasma genitalium, that has become difficult to treat with current antibiotics.
The subject of the study initially attended a sexual health clinic after experiencing symptoms for two days, a fortnight after having unprotected sex with a partner. Initially, he was given a week-long course of the antibiotic, doxycycline, while he waited for the results of a test to identify the exact bacterial cause of the infection.
The results of the test confirmed that the patient was infected with Mycoplasma genitalium, and he has subsequently prescribed another antibiotic, azithromycin. The lab analysis revealed that it was a treatment-resistant strain of the infection, and he was then given a third antibiotic, moxifloxacin.
Chloramphenicol is effective and easy to access
Five days after completing all the courses of antibiotics, the patient was still experiencing symptoms. After considering other treatment options, which had to be ruled out due to cost, availability, or licensing issues, the researchers prescribed a 1g tablet of chloramphenicol, to be taken four times a day for 14 days.
The researchers opted for this antibiotic due to test tube evidence showing that chloramphenicol could stop Mycoplasma genitalium and the ease of access to the drug. At the end of the 14-day course, the patient’s symptoms had cleared, and clinical tests confirmed that he no longer had urethritis.
“When considering what to choose after first- and second-line treatment failure, there is a lack of novel agents readily available in the UK, and a paucity of data to underpin recommendations,” wrote the researchers.
Chloramphenicol is usually well tolerated by patients and serious side effects are rare (one in 30,000). The researchers say the absence of viable effective alternatives merits further investigation into its use.
“Options for third-line therapies in treatment-resistant Mycoplasma genitalium are urgently required. Chloramphenicol may have an application in this scenario, and should be considered as a possible drug for investigation,” they concluded.