Passmed Rheumatology Mushkies Flashcards
What shoulder never be prescribed with methotrexate?
Co-trimoxazole/trimethoprim
What is the MOA of methotrexate?
Antimetabolite that inhibits DHFR, which is essential for the synthesis of purines and pyrimidines
What are 3 indications of methotrexate?
- RhA
- Psoriasis
- Chemo for e.g. ALL
What are 5 adverse effects of methotrexate?
- Mucositis
- Myelosuppression
- Pneumonitis
- Pulmonary fibrosis
- Liver fibrosis
What are some guidelines regarding methotrexate and pregnancy?
- Women should avoid pregnancy for at least 6m after treatment has stopped
- Men using methotrexate need to use effective contraception for at least 6m after treatment
How often is methotrexate given?
Weekly
How is methotrexate monitored?
FBC, U&E and LFTs before treatment, weekly until therapy stabilised, then every 2-3m
What should be co-prescribed with methotrexate?
Folic acid 5mg once weekly, taken >24hrs after methorexate dose
What is the starting dose of methotrexate?
7.5mg weekly
What is the usual dose of one tablet of methotrexate?
2.5mg
What is the treatment of choice for methotrexate toxicity?
Folinic acid
What drug increases the risk of methotrexate toxicity secondary to redeced excretion?
High dose aspirin
When does the risk of osteoporosis increase significantly for pts on steroids?
Equivalent of 7.5mg prednisolone per day for 3 or more months
If pt is at risk of corticosteroid induced osteoporosis, what should they be prescribed?
- Calcium
- Vitamin D
- Bisphosphonate
What drugs are associated with an increased risk of atypical stress fractures?
Bisphosphonates
What is the MOA of bisphosphonates?
Inhibit osteoclasts by reducing recruitment and promoting apoptosis
What are 4 uses for bisphosphonates?
- Prevention and Tx of osteoporosis
- Hypercalcaemia
- Paget’s
- Pain from bone metastases
What are 5 complications of bisphosphonates?
- Oeseophageal reactions (oesophagitis, oesophageal ulcers)
- Osteonecrosis of the jaw
- Atypical stress fractures
- Acute phase response (fever, myalgia and arthralgia may occur following administration)
- Hypocalcaemia
How does the BNF suggest pts should take bisphosphonates?
Tablets should be swallowed whole with plenty of water while sitting or standing; to be given on an empty stomach at least 30 minutes before breakfast (or another oral medication); patient should stand or sit upright for at least 30 minutes after taking tablet
When should bisphosphonates be stopped after 5 years of treatment?
- Pt <75 y/o
- Femoral neck T score >-2.5
- Low risk according to FRAX/NOGG
What kind of receptors do IFNa/b bind to?
Type I receptors
What kind of receptors do IFNy receptors bind to?
Type II receptors
What are 2 side effects of IFNa?
Flu-like symptoms and depression
What are 4 uses of IFNa?
- Hep B&C
- Kaposi’s sarcoma
- Metastatic RCC
- Hairy cell leukaemia