About the study


About the study GTOG

GTOG – Gentamicin in the Treatment of Gonorrhoea opening soon

About the study:


This is a randomised controlled trial to compare the clinical effectiveness and safety of gentamicin and ceftriaxone in the treatment of gonorrhoea. Currently the antibiotic ceftriaxone is used to treat gonorrhoea but there is increasing evidence that this antibiotic is becoming less effective over time and will stop curing patients with gonorrhoea within the next few years.

Professor Jonathan Ross is a Consultant Physician based at the University Hospitals Birmingham Trust and he set up this study to assess whether gentamicin is a safe and effective treatment for gonorrhoea. Gentamicin is an existing antibiotic which is already used to treat other infections and might also be effective against gonorrhoea. A review looking for previously published studies which assessed gentamicin found that the existing trials are of low quality and that there are no recent clinical trials.


Treatment options:


Patients diagnosed with gonorrhoea infection will be asked to join the study and will be randomised to either gentamicin or ceftriaxone. Both are given by injection. All patients will also receive azithromycin which is currently given in combination with ceftriaxone in the treatment of gonorrhoea. Patients will be asked to come back to clinic 2 weeks after their treatment to be tested to see if their gonorrhoea has cleared. Patients will be given a £15 voucher at the end of their follow-up visit as thank you for their time whilst taking part in the trial.


Trial schema: 


Trial Schema

Figure 1: Showing the trial schema for GTOG


Study Outcomes:


Primary outcome:

  • To determine whether gentamicin is an acceptable alternative to ceftriaxone, in the treatment of gonorrhoea.

Secondary outcomes:

  • To determine whether a single intramuscular dose of gentamicin is safe and well tolerated
  • To determine whether a single intramuscular dose of gentamicin is cost effective to the NHS when used to treat gonorrhoea
  • To determine the relationship between clinical effectiveness and the laboratory measurement of antibiotic effectiveness

Eligibility criteria:


Inclusion criteria:

  • Men or women aged 16-70 years.
  • Diagnosis of untreated genital, pharyngeal or rectal gonorrhoea based on a positive gram stained smear on microscopy, or positive nucleic acid amplification testing (NAAT).
  • Written informed consent provided

Exclusion criteria

  • Concurrent bacterial sexually transmitted infection (apart from chlamydia).
  • Known contra-indications or allergy to gentamicin, ceftriaxone or azithromycin.
  • Pregnant or breast-feeding.
  • Complicated gonorrhoea infections e.g pelvic inflammatory disease, epidiymo-orchitis.
  • Weight less than 40kg.
  • Received ceftriaxone or gentamicin within the preceding 28 days

Participating UK centres:


  1. Professor Jonathan Ross – University Hospitals Birmingham Trust
  2. Dr Janet Wilson – Leeds Teaching Hospitals NHS Trust
  3. Dr John White – Guy’s and St Thomas’ NHS Trust
  4. Dr Gabriel Schembri – Central Manchester University Hospitals NHS Foundation Trust
  5. Dr Raj Patel – Southampton University Hospitals NHS Trust
  6. Dr Phillip Hay – St George’s –  University of London
  7. Dr Christine Bowman – Sheffield Teaching Hospitals NHS Foundation Trust
  8. Dr Claudia Estcourt – Bart and the London Queen Mary’s School of Medicine and Dentistry