1. Arthritis Flashcards
Rheumatoid Arthritis
What is it?
When the immune system attacks the synovium (lining of the inner surface of joints), causing inflammation
Rheumatoid Arthritis symptoms
- Swollen joints
- Stiff joints
- Loss of motion
- rheumatic nodules
- Fatigue, fever, weight loss
DMARDs examples
AFFECTS IMMUNE RESPONSE:
* Methotrexate
* Azathioprine
* Ciclosporin
CYTOKINE MODULATOR
* TNFalpha-inhibitor
* Targeted synthetic
* Other biological
ANTI-MALARIAL
* hydroxtchloroquine
OTHERS: sulfasalazine, penicillamine
DMARDs risks
DMARDS suppress immune system to control inflammation so can cause blood dyscrasias, thus increasing the likelihood of an infection
Antimalarial DMARDs are an exception
Rheumatoid arthritis treatment guideline
1st line
1st line: Convetional DMARD; such as leflunomide, sulfasalazine or hydroxychloroquine (in mild disease). DMARds are slow to work
Can be used with steroids (short term) during flare ups to reduce inflammation
Can also be used with NSAIDs + gastro-protection
Rheumatoid arthritis treatment guideline
2nd line/3rd line
2nd line: Combination therapy with two conventional DMARDs
3rd line: Biological drug (e.g rituximab) (ADD it to conventional drug in severe active arthritis)
Methotrexate mechanism of action
blocks dihydrofolate reductase (which converts folic acid into tetrahydrofolate). The enzyme is needed to make purine and pyrimidines. This slows down the replication of immune cells in rheumatoid arthritis
Methotrexate indications
LOW DOSE TREATS:
Crohn’s disease, Psoriasis
HIGH DOSE TREATS:
Cancer
Methotrexate dosing and dispensing
Taken once weekly.
The day must be indicated on the prescription.
The specific day should be written on the outer packaging when dispensing methotrexate
Patients must carry an alert card, treatment booklet - can indicate their scheduled dosing day in it
Forgotten methotrexate doses
If it has been more than 3 days since the patient was last due for their dose, they should take the next scheduled dose at the normal time.
If it has been 3 days or less since the patient was last due for their dose, they can take the next dose as soon as they remember
If a patient vomits within a few hours of taking dose, they should not take another dose
Methotrexate and folic acid dosing
Folic acid is co-prescribed with methotrexate
Examples of possible folic acid regimens
- Folic acid 5mg once weekly, should be taken on a different day to methotrextae
- 1 or 5mg once daily except on the day methotrextae is taken
Folic acid antagonises methotrexate’s effect
Methotrexate side effects/cautions
- Immunosuppression therefore monitor FBC
Patients must report signs of infection or blood disorder: fever, sore throat, mouth ulcer, bleeding - Nephrotoxicity AND drug is also renally cleared and can acummulate in renal impairement
CAUTION: dehydration, risk factor for AKI - Hepatotoxicity: patient must report signs of dark urine, jaundice, persistent vomiting, abdominal pain
CAUTION: ascites - Pulmonary toxicity: Patients must report signs of a cough, shortness of breath, fever
CONTRA-IND: pleural effusion - GI toxicity (as methotrexate reduces cell replication, this affects the rapidly dividing cells of the muscosa, leaving it vulnverable to inflammation - mucositis) Mucositis can be treated with folinic acid.
Stomatitis, diarrhoea are early signs of mucositis - should be stopped if this occurs
CAUTION: peptic ulcers, ulcerative colitis
FOLINIC ACID IS DIFFERENT TO FOLIC ACID
Methotrexate and risk of pregnancy
Methotrexate is teratogenic as it is an anti-folate drug
Both men and women must use effective contraception during and 6 months after treatment
Methotrexate and breastfeeding
Methotrexate is present in breastmilk. Do not breastfeed.
Methotrexate handling
Avoid skin contact with cytotoxic drugs such as methotrexate - must wear gloves
Osteoarthritis
What is it?
When cartilage wears away and prevents smooth movement. The space between joints narrow, as they rub against eachother
