Mercaptopurine [off-label use] (Adults only, non-renal, gastroenterology patients)
Publish public / Applies to: NHS Grampian / Version 1 /
Coordinator / Authorised for issue by / Document no:
NHSG/SCPa/Mer/MGPG353
Gastroenterology / Medicines Guidelines
and Policies Group
Effective date: August 2009
Signature:
L Crighton / Signature:
C Hind / Review Date: August 2011
Supersedes: n/a
Please keep this document in the patients notes
UNCONTROLLED WHEN PRINTEDReview date: August 2011NHSG/SCPa/Mer/MGPG353- 1 -
SCP and Prescribing Information for General Practitioners for Mercaptopurine (off-label use) Adults only Gastroenterology – Version 1
Shared Care Policy and Prescribing Information for General Practitioners forMercaptopurine [off-label use] (Adults only, non-renal, gastroenterology patients)
PATIENT NAME
UNIT NUMBER
CHI NUMBER
ADDRESS
DATE OF BIRTH
Insert patient sticker here / HOSPITAL
TELEPHONE NO
CONSULTANT (print name)
SIGNATURE / WARD
DATE
Therapeutic Indication for this patient:(to be completed by consultant)
Dosage/preparation/route/frequency of administration:(to be completed by consultant)
UNCONTROLLED WHEN PRINTEDReview date: August 2011NHSG/SCPa/Mer/MGPG353- 1 -
SCP and Prescribing Information for General Practitioners for Mercaptopurine (off-label use) Adults only Gastroenterology – Version 1
Shared Care Policy and Prescribing Information for General Practitioners forMercaptopurine [off-label use] (Adults only, non-renal, gastroenterology patients)
SAFE PRACTICE IS THAT THE CLINICIAN WHO ORDERS THE TEST MUST ACT ON THE RESULT
CARE WHICH IS THE RESPONSIBILITY OF THE HOSPITAL CONSULTANT
Baseline:
1.FullBlood Count (FBC), urea, creatinine and electrolytes (U&Es), liver function tests (LFTs).
† Optional Check - TPMT (thiopurine methyltransferase). Deficiencies of the enzyme TPMT may result in an increased risk of toxicities and more frequent blood monitoring may be required.
Consultant to advise GP if more frequent monitoring required as a result of this test
2.Copy of results to be sent to GP.
3.Initiation of therapy and recommendations for dose increments.
4.Decision on final dose required for patient.
5.Monitoring clinical response to treatment.
6.Advise patients to immediately report signs or symptoms of bone marrow suppression, e.g. infection, inexplicable bruising or bleeding. / CARE WHICH IS THE RESPONSIBILITY OF THE GENERAL PRACTITIONER
1.Prescribing of medication under guidance of consultant.
2.Check before prescribing medication that the monitoring is up to date and results are within the normal range.
3.GP should be aware that the drug can cause bone marrow suppression, leucopenia, increased risk of malignancy – lymphomas and skin cancer.
- Patients should be asked about the presence of sore throat, abnormal bruising or bleeding at each visit.
- Check for development of lymphomas and other malignancies particularly of the skin.
4.The General Practitioner has primary responsibility for monitoring therapy according to the schedule below[¥]:
- FBC and LFTs (incl. ALT and Alk Phos) weekly for the first month or until maintenance dose achieved.
- FBC and LFTs monthly thereafter.
NOTE: in addition to absolute values for haematological indices a rapid fall or a consistent downward trend inany value should prompt caution and extra vigilance.
If something unexpected occurs Contact Consultant.
Notify the consultant if the drug is stopped.
UNCONTROLLED WHEN PRINTEDReview date: August 2011NHSG/SCPa/Mer/MGPG353- 1 -
SCP and Prescribing Information for General Practitioners for Mercaptopurine (off-label use) Adults only Gastroenterology – Version 1
Shared Care Policy and Prescribing Information for General Practitioners forMercaptopurine [off-label use] (Adults only, non-renal, gastroenterology patients)
MONITORING: - Action to be taken if:
- WBC <4.0x109/L
- Neutrophils <2x109/L
- Platelets <150x109/L
- >2-fold rise in ALT or Alk Phos (from upper limit of reference range)
- MCV>105flinvestigate and if B12 or folate low start appropriate supplementation
- Abnormal Bruising, sore throat, rash, oral ulcerationwithhold until discussed with consultant
- Unexplained feverwithhold until discussed with consultant
- Malignancieswithhold until discussed with consultant
FOR SPECIFIC PRODUCT INFORMATION PLEASE CONSULT THE CURRENT SUMMARY OF PRODUCT CHARACTERISTICS ( AND THE BNF (
Other information
- Live vaccines should be avoided in patients taking mercaptopurine.
- Single pneumococcal vaccination and annual influenza vaccine should be given.
- Varicella Zoster Immunoglobulin should be given to non-immune individuals if exposed to shingles or chickenpox.
- There are a number of drug interactions that must be considered when a new drug is prescribed please refer to Summary of Product Characteristics, BNF or contact Medicines Information
Inhibition of the anticoagulant effect of warfarin, when administered with mercaptopurine has been reported.
- To minimise the risk of skin cancer, exposure to sunlight and ultraviolet light should be limited by wearing protective clothing and using sunscreen with a high protection factor.
Discuss with consultant. Mercaptopurine should not be given to patients who are pregnant or likely to become pregnant without careful assessment of risk versus benefit.
Adequate contraceptive precautions should be advised if either partner is receiving mercaptopurine.
Breast-feeding
Discuss with AberdeenMaternityHospital or contact Medicines Information. Discontinue breast-feeding.
Responsibilities of GPs undertaking monitoring
A GP agreeing to monitor mercaptopurine should:
- Ensure that the relevant monitoring requirements are undertaken at the correct frequency,
- Ensure that the test results are checked for any abnormality as soon as the results are available,
- Ensure abnormal results are acted upon,
- Only continue to prescribe mercaptopurine if it is being satisfactorily monitored,
- Contact the consultant in the event of a drug reaction or monitoring abnormality or any other concerns,
- Be alert for any of the known adverse reactions.
UNCONTROLLED WHEN PRINTEDReview date: August 2011NHSG/SCPa/Mer/MGPG353- 1 -
SCP and Prescribing Information for General Practitioners for Mercaptopurine (off-label use) Adults only Gastroenterology – Version 1
[¥]Consultant to advise if more frequent monitoring required as a result of TPMT test.