Shared Care Guidelines- Oral Methotrexate
Date:
Patient Identifier
INDICATION:
Methotrexate is indicated for the treatment of moderate to severe arthritis.
DOSAGE AND ADMINISTRATION:
Dose of 7.5mg – 25mg once each week. Dose adjusted by specialist according to
response. Doses outside this range may be considered with prior agreement of
specialist and GP.
Lower doses should be used in the fail elderly or if there is no significant renal
impairment.
Always prescribe methotrexate in multiples of the 2.5mg tablets strength
to avoid confusion with the 10mg tablet.
Folic acid supplements:
Folic acid is normally taken to reduce the risk of gastro-intestinal and haematological
toxicity. Dosage is within the range of 5 - 10mg once weekly up to 5 - 10mg once
daily depending on independent consultant preference.
HOSPITAL SPECIALIST RESPONSIBILITIES
Summary:
• Baseline tests and safety monitoring
• Disease monitoring
• Check varicella immmunity
Baseline Tests
• CXR
•LFTs
• FBC
•U&Es
• Serum creatinine
Reviewing safety Monitoring
Review results of safety monitoring
and requests additional tests as
required.
Disease Monitoring
Response to treatment and need to continue therapy. The hospital specialist will
continue to review the patient at specified intervals.
GP RESPONSIBILITIES
Summary
• Prescribe methotrexate & folic acid supplements
• Arrange ongoing monitoring
• Identify potential adverse effects
• Ensure no adverse drug interaction with other medicines
• Continued prescribing is appropriate for patients attending regular review
Safety Monitoring
See the British Society for Rheumatology (BSR) guidelines for Second Line Drug
monitoring- Appendix 1
Test results should be recorded in the patient’s booklet.
ADVERSE EFFECTS AND PRECAUTIONS
Nausea: Commonly encountered. Can occur at ant time during therapy. May
resolve with dose reduction and/or addition of anti-emetic medication
Decreased resistance to infection: Especially respiratory / urinary tract or shingles
/ chickenpox. Temporarily withhold methotrexate if patient is systemically unwell with
significant infection requiring anti-infective intervention.
Alopecia, rash, stomatitis, diarrhoea: Contact the specialist if severe or persistent.
Respiratory function: Very rarely, methotrexate can cause interstitial pneumonitis,
pulmonary oedema and fibrosis. Patient complaining of unexplained dyspnoea or
unexplained dry cough should be referred immediately to the specialist.
Alcohol: Patient are advised that alcohol consumption should be advised or kept to
a minimum, due to the increased potential for liver toxicity.
Contraindications include: Female patient must be advised not to conceive whilst
receiving methotrexate. A reliable form of contraception should be used by men and
women whilst on methotrexate and for at least 3 months after discontinuing it.
Discontinue methotrexate and refer immediately if a patient or partner discovers they
are pregnant whilst taking methotrexate.
Contraindications include:
• Severe renal or hepatic impairment.
• Chronic or recurrent infections especially respiratory or urinary tract.
• Severe anaemia, leucopenia or thrombocytopenia.
• Untreated folate deficiency.
• History of alcohol abuse / cirrhosis
• Hepatitis
Vaccines: Live vaccines should be avoided in patients taking methotrexate.
Methotrexate should be discontinued for 3 months prior to the live vaccines and not
restarted until 2 weeks after vaccination. Live vaccines are BCG, MMR, measles,
varicella and yellow fever.
Pneumococcal vaccine (IMPORANT revaccination is not recommended see
BNF) and ‘FLU’ vaccines are recommended.
Passive immunisation should be carried out using Varicella zoster immunoglobulin
(VZIG) in non –immune patients if exposed to chickenpox or shingles.
DRUG INTERACTIONS
The following drugs may cause an increase in methotrexate serum level and should
be used with caution. A FBC taken 1-2 weeks following initiation of new therapy is
recommended to ensure toxicity has not occurred.
• NSAIDs & Aspirin:
• Tetracycline:
• Penicillins:
• Herbal Remedies
Although a well documented interaction, NSAIDS or
Aspirin (<300mg) are unlikely to cause any clinically
significant adverse effect.
A documented interaction unlikely to cause an adverse
effect.
A documented interaction unlikely to cause an adverse
effect.
Avoid if possible due to unknown interaction potential
!!! DO NOT prescribe concomitant Trimethoprim or Co-trimoxazole !!!
due to risk of pancytopenia.
Co-prescription of drugs with potential hepatotoxic or nephrotoxic effects is also not
advisable. Abnormal renal function can make these interactions for severe.Please
contact the Pharmacy if you are in doubt about possible hepatotoxic and
nephrotoxicty.
Please refer to the Summary Product Characteristics for further drug interaction
information- www.medicines.org.uk.
COMMUNICATION
Rheumatology department-Barnet Hospital: 020 82164969
Rheumatology department-Chase Farm Hospital: 020 83751608
Rheumatology department –Edgware Hospital: 020 87326697
Pharmacy Medicines Information- 020 83751486
Prepared: March 2005
Review: March 2008
Appendix 1:
BSR Methotrexate monitoring guidelines
A typical dose regimen may be: - 7.5mg weekly increasing by 2.5mg every 6
weeks to a maximum of 25mg. Lower doses should be used in the frail elderly or if
there is significant renal impairment. Regular folic acid supplements are thought to
reduce toxicity. Cotrimoxazole or trimethoprim must be avoided in patients taking
methotrexate. Excess alcohol should be avoided. Live vaccines should be avoided in
patients taking methotrexate. NSAIDs in addition to the above doses of methotrexate
are not contraindicated. Annual ‘flu vaccine should be given.
Pretreatment assessment: - FBC, U&E's, creatinine, LFT's, Chest Xray.
Monitoring: - FBC fortnightly until 6 weeks after last dose increase and provided it is
stable monthly thereafter. LFT's (incl. AST or ALT) with each blood test. U&E's 6-12
monthly (more frequently if there is any reason to suspect deteriorating renal
function).
Action to be taken: WBC <4.0x10^9/l
withhold until discussed with
rheumatologist
Neutrophils<2.0x10^9
withhold until discussed with
rheumatologist
Platelets<150x10^9 /l
withhold until discussed with
rheumatologist
>2-fold rise in AST, ALT
withhold until discussed with
rheumatologist (from upper limit of reference range)
Unexplained fall in albumin
withhold until discussed with
rheumatologist
Rash or oral ulceration
withhold until discussed with
rheumatologist
New or increasing dyspnoea or cough
withhold until discussed with
rheumatologist
MCV>105fl
investigate and if B12 or folate low start
start appropriate supplementation
Significant deterioration in renal function
reduce dose
Abnormal bruising or sore throat
withhold until FBC result available
Please note that in addition to absolute values for haematological
indices a rapid fall or a consistent downward trend in any value should
prompt caution and extra vigilance.