Methotrexate Flashcards
MOA of Methotrexate
Inhibit dihydrofolate reductase essential for the synthesis of purines and pyrimidines
Dosing of Methotrexate in a autoimmune condition
Should be taken once a week
Methotrexate prescribing
Only one strength is prescribed and dispensed (2.5mg)
Prescription and dispensing label should clearly show dose and frequency of administration
Side effects of Methotrexate to report immediately
Onset of blood disorder ( sore throat, bruising, mouth ulcers)
Liver toxicity ( N,C, abdominal pain , dark urine)
Respiratory ( SOB)
Seek immediate medical attention if OD is suspected
Caution with methotrexate
Blood count
G.I toxicity
Liver toxicity
Pulmonary toxicity
See photo for explanation
State what to do if GI toxicity occur while on methotrexate
Withdraw treatment
Signs of GI toxicity
Stomatitis( inflamed or sore mouth or diarrhoea
Discontinue methotrexate if pneumonitis suspected . T/ F
True
Methotrexate and liver toxicity
Do not start treatment or discontinue if abnormal liver function test results
Methotrexate monitoring requirements
FBC, renal, liver test every 1-2 weeks until stabilised
Then every 2-3 months
Patients and carer advise
Advise patients to report all signs of infection especially sore throat
What treatment may be required in acute methotrexate toxicity
Folinic acid
Use of Folinic acid( calcium folinate)
Prevents methotrexate induced mucositis and myelosuppression
Patients and carer advise on methotrexate
Report signs of blood disorder
Signs of liver toxicity
Respiratory effects
Avoid self medication with OTC aspirin and NSAID
Issue methotrexate treatment booklet
List three drugs that increases the toxicity of Methotrexate when given together
NSAIDs
Penicillin
High dose Aspirin
