NHS Ayrshire & Arran example guideline 1: Guideline for the use of intravesical gentamicin for the management of resistant uti in women or men aged ≥ 18 years (unlicensed use)

There are small groups of patients who have repeated frequent urinary tract infections (UTIs) that cause systemic upset and which require either oral or parenteral antibiotics to achieve symptom relief. These patients have to repeatedly attend both primary and secondary care for treatment and their quality of life is poor, both because of the symptoms the infection has caused, and because of their repeated need to seek medical treatment. Some of these patients have had ileocystoplasties for bladder reconstructions, others have intact bladders but need to perform intermittent catheterisation or have indwelling catheters with repeat sepsis.

The purpose of this guideline is to provide a framework to ensure that intravesical gentamicin is prescribed appropriately and used safely.

While gentamicin intravenous injection possesses a UK Marketing Authorisation, its use for intravesical administration in the management of resistant urinary tract infections in women or men is an unlicensed indication. Refer to Section 9(b) of the NHS Ayrshire & Arran Code of Practice for Medicines Governance for further information on ‘off label’ use of medications.

Within NHS Ayrshire & Arran, intravesical gentamicin will only be initiated by a consultant urologist, with a specialist interest in recurrent urinary tract infection.

The urology consultant initiating therapy will:

• consent the patient
• provide the patient with written and verbal information about the treatment
• ensure the patient has been adequately trained to administer the treatment
• prescribe gentamicin for so long as it is indicated (initially one month’s supply followed by three monthly instalments in the absence of complications)
• send a standard letter to patient’s GP on commencement of intravesical gentamicin including the rationale for treatment, treatment regimen, potential complications, and contact numbers.

Women or men who have an intact bladder and suffer repeated, difficult to treat, urinary tract infections i.e. more than 6 proven urinary tract infections in any 12 month period, or at least 1 infection requiring hospital admission in any 12 month period with a background of recurrent urinary tract infections.

• These patients may have failed on long term oral antibiotic prophylaxis or be intolerant to the oral agents currently available for this indication.
• Discussion has taken place with the consultant microbiologist to ensure that no other oral antimicrobial treatment options are available and that the patient does not have UTIs with gentamicin resistant organisms.
• The guidelines should only be used when all conventional measures to reduce the frequency of urinary tract infections have failed, including a trial of long term, low dose antibiotic prophylaxis; Cystistat® or iAluril® instillations, use of cranberry juice or capsules or d-mannose or hipprex with vitamin c supplements; high fluid intake and frequent voiding’ and a check of intermittent self catheterisation technique where applicable. An underlying treatable cause for infections will also have been ruled out with upper tract imaging and cystoscopy.
• The patient should be made aware by the clinicians responsible for ongoing care that the treatments is of limited benefit and has not been subjected to detailed research. They should then take part in a full discussion and decide for themselves whether they want to use this novel treatment. This discussion must be documented in the patient’s medical notes along with the patient’s consent if they decide to proceed.
• The patient’s technique in performing intermittent self catheterisation should be checked and found to be satisfactory. If not already able to self catheterize or if technique is poor, patients must be taught self catheterisation technique by a urology specialist nurse.
• Consideration also must be given to whether there are any relatives in the immediate household with a gentamicin allergy and any necessary precautions.

Dosage: Gentamicin 80mg instilled intravesically once daily (at night) for 8 weeks. The frequency will then be reduced to twice every week for the next 8 weeks, then to once per week for 8 weeks and then treatment stopped (6 month treatment duration in total)

Duration: Therapy is intended to be 6 months in the absence of complications or a change in circumstances.

Administration: Gentamicin 80mg diluted in 50ml of sterile sodium chloride 0.9% should be instilled in the bladder nightly, after completion of a conventional bladder washout, and the catheter withdraw, leaving the solution in the bladder overnight. The solution will be voided spontaneously in the morning, or be removed by routine self catheterisation.

Gentamicin levels: gentamicin levels will be checked one week after initiation of intravesical gentamicin, and treatment will be discontinued if gentamicin levels > 1mg/L. These will be rechecked at the annual reviews.

• Prescriptions will be written by the Urology Consultants only—either on a hospital out -patient script or on a CDM discharge letter. Initially one month’s supply will be issued followed by 3 monthly instalments in the absence of complications.
• Gentamicin 80mg/2mls injection (for intravesical use) should be prescribed in multiples of five = 30 amps/month. Sodium chloride 0.9% 20ml ampoules should be prescribed in multiples of 20 (remember 3 ampoules will be required per dose) = 100 ampoules/month.
• Equipment to facilitate intravesical administration will initially be provided by the Specialist Nurse (for up to 1 month) and the patient’s GP will prescribe subsequent supplies.

Patients will be reviewed at Day 7, 1 month, 2 months, 4 months and 6 months. Patients would be considered for a further course if needed.

At each review, patients will be assessed for clinical benefits of treatment, reduction in hospital/ high level of care with sepsis admissions, adverse drug reactions and a decision made regarding continuation of treatment.

At the annual review, serum creatinine and gentamicin levels will be checked and consideration of any audiology issues.

If no clinical benefit is demonstrated at the 3 month review, or any reviews thereafter, intravesical gentamicin will be discontinued.

If gentamicin resistance or adverse effects develop at any time during treatment, then intravesical gentamicin will be discontinued.

Gentamicin may cause local irritation in the bladder. Ototoxicity and nephrotoxicity are unlikely adverse effects.

The Medicines and Healthcare products Regulatory Agency (MHRA) yellow card scheme should be used to report any adverse effects which are serious, medically significant or result in harm from intravesical gentamicin. This will be done online at www.mhra.gov.uk/yellowcard , via Yellow Card mobile app or via paper Yellow Card form found in BNFs.

An audit of all patients commenced on intravesical gentamicin will be undertaken within the urology department. Data recorded will include; efficacy of treatment, number/ type of hospital admissions due to UTIs, number of episode of symptomatic UTIs, side effects (including neurotoxicity and ototoxicity) and the development of any gentamicin resistance.

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