Shared Care Guidance

Rifaximin for the treatment of Hepatic Encephalopathy

This shared care agreement outlines the way in which the responsibilities for managing the prescribing of rifaximin 550 mg tablets for the reduction in recurrence of episodes of overt hepatic encephalopathy in patients ≥ 18 years can be shared between the Secondary Care Specialist and the General Practitioner.

Indication:

Rifaximin 550 mg tablets are indicated for the reduction in recurrence of episodes of overt hepatic encephalopathy in patients ≥ 18 years of age. The Summary of Product Characteristics (SPC) advises that in the pivotal study, 91% of the patients were using concomitant lactulose. Consideration should also be given to official guidance on the appropriate use of antibacterial agents.

Dose & Administration:

The recommended dose of rifaximin in adult patients ≥ 18 years is one 550mg tablet twice daily.

The clinical benefit was established from a controlled study in which subjects were treated for 6 months. Treatment beyond 6 months should take into consideration the individual balance between benefits and risks, including those associated with the progression of hepatic dysfunction. Rifaximin can be administered with or without food, and should be given with a glass of water.

Adverse Effects:

Common adverse events (occurring in ≥1/100 to <1/10 of patients) as listed in the SPC are: depression; dizziness; headache; dyspnoea; abdominal pain and distension; diarrhoea, nausea, vomiting, ascites, rashes, pruritus, muscle spasms, arthralgia, peripheral oedema. See SPC for full details of adverse events.

Rifaximin was launched in 2013 and has black triangle (▼) status. All suspected reactions (including those considered not to be serious and even where the causal link is uncertain) should be reported to the MHRA.

Contraindication:

Contraindications:

  • Hypersensitivity to rifaximin, rifamycin-derivatives or to any of the product’s excipients
  • Cases of intestinal obstruction

Special warnings/precautions:

  • The potential association of rifaximin treatment with Clostridium difficile-associated disease and pseudomembranous colitis cannot be ruled out.
  • Concomitant administration of rifaximin with other rifamycins is not recommended.
  • Patients should be informed that despite the negligible absorption, in common with other rifamycins, rifaximin may cause a reddish discolouration of the urine.
  • Hepatic Impairment: use with caution in patients with severe (Child-Pugh C) hepatic impairment and in patients with MELD (Model for End-Stage Liver Disease) score > 25.
  • Whilst interactions have not been commonly reported, the use of additional contraceptive precautions is recommended, in particular if the oral contraceptive oestrogen content is below <50 micrograms.

Cautions & Drug Interactions:

The SPC states that whilst studies in healthy subjects have shown no significant interaction, in hepatic impaired patients it cannot be excluded that rifaximin may decrease the exposure of concomitant CYP3A4 substrates administered (e.g. warfarin, antiepileptics, antiarrhythmics). An in vitro study has suggested that rifaximin is a moderate substrate of P-glycoprotein(P-gp) and is metabolized by CYP3A4. It is unknown whether concomitant drugs which inhibit P-gp and/or CYP3A4 can increase systemic exposure of rifaximin.

Monitoring Requirements:

The SPC does not identify any specific monitoring requirements for this drug.

Parameters for Intervention:

There are no specific parameters for intervention in terms of blood tests, therapeutic monitoring, etc. Any possible rifaximin-related adverse effects must be reported back to the Secondary Care Specialist who will then make a decision as to the clinical appropriateness of continuing therapy.

Shared Care Responsibilities:

Secondary Care Specialist

  1. Send a letter to the GP with Shared Care Guidelines requesting shared care for the patient.
  2. Initiation of rifaximin therapy.Prescribing will be transferred over to primary care after the first pack of rifaximin has been utilised by the patient.
  3. Discuss the benefits and side effects of treatment with the patient.
  4. Regular follow-up of patient; communicating relevant information to Primary Care colleagues accordingly. This will include the results of any blood tests and other ongoing monitoring parameters relevant to disease progression.
  5. Report adverse events to the Medicines and Healthcare Products Regulatory Agency (MHRA).
  1. Act promptly on any communication from GP colleagues requesting advice and support.
  2. Review the patient after he/she has received 6 months of rifaximin therapy.
  3. Communicate the decision to stop or continue therapy beyond the 6 months period to Primary Care colleagues; explaining clearly the benefits/risks to the patient from doing so.

Primary Care Practitioner

  1. Submit letter of reply confirming acceptance.
  2. Monitor patient’s overall health and wellbeing.
  3. Prescribe the drug treatment as described within this document.
  4. Report to and seek advice from the Secondary Care Specialist on any aspect of patient care that is of concern and may affect treatment.
  5. Refer patient to the Specialist if his or her condition deteriorates.
  6. Report any rifaximin-related adverse events to the hospital specialist and MHRA.
  7. Stop treatment on the advice of the Secondary Care Specialist.

Patient (and if appropriate, the carer):

  1. Report to the Secondary Care Specialist or GP if he or she does not have a clear understanding of the prescribed treatment.
  2. Share any concerns in relation to treatment with rifaximin.
  3. Report any adverse effects to the Secondary Care Specialist or GP whilst taking rifaximin therapy.

Contact Numbers for Advice and Support:

Colchester Hospital University NHS Foundation Trust (01206) 747474 (Switchboard)

Consultant Gastroenterologists:

Dr Ian Gooding(01206) 744233 [fax (01206) 742931]

Dr Mary McStay(01206) 745210 [fax (01206) 742931]

CHUFT Pharmacy Department(01206) 742355

CHUFT Medicines Information Help Line:(01206) 742161

References

Summary of Product Characteristics – Targaxan® (rifaximin) 500mg film-coated tablets. Norgine Limited.

Section A (to be completed by Secondary Care Specialist):

Hospital Number:
NHS No:
Date:
GP Courier No:
GP Name:
Name of patient:
Date of Birth:
Address:

Background:

Medications:

Dear GP,

See attached clinic letter. Please can you sign and return (using the above fax number) to indicate you are in agreement with the Shared Care Guidelines.

Yours sincerely,

Section B (to be completed by General Practitioner):

The above patient (with associated rifaximin treatment) has been accepted into our monitoring service.

Accepting GP Name:
Accepting GP Signature:
Date:

Practice Stamp:

Version: 1

Author: Paul Mills (Principal Pharmacist-CHUFT)

Reviewed by: Dr Ian Gooding (Consultant Gastroenterologist),Dr Mary McStay (Consultant Gastroenterologist), Jackie Wallis (Pharmacist - CHUFT), Sheila Baldwin (Head of Medicines Management, NHS North East Essex Clinical Commissioning Group)

Approved by: NEEMMC Jan 2015

Next review date: Jan 2017