CPT2: Osetoarthritis Flashcards
What is osetoarhtritis?
A degenerative joint disease which mainly affects the articular cartilage. It is associated with ageing and will most likely affect the joints that have been continuously stressed throughout the years including the knees, hips, fingers and lower spine region.
What is the prevalance and common onset of OA?
Increases with age and more common in women
Onset usually in over 60s
What are risk factors for osteoarthritis?
- Increasing age
- Female
- Congenital abnormalities
- Obesity
- Genetic predisposition
- Previous injury
- Previous disease such as rhemuatoi arthritis or gout
What are the symptoms of characterisitics of osteoarthritis?
- Mainly affects the joints of the hands and larger joints
- Affects joints asymmetrically and is localised to synovial joints.
- Main symptoms are pain and stiffness.
- Pain worsens on moving joint
- Stiffness in morning (last less than 30mins)
What happens to the synovial joints in OA?
- OA occurs when the cartilage layer covering the joint is degraded.
- This results in exposure of underlying subchondral bone resulting in sclerosis.
- abnormal hardening of body tissue
- Reactive remodeling changes then occur that lead to the formation of osteophytes and subchondral bone cysts.
- Osteophytes - bony lumbs on bones around joints
- Subchondral bone cysts - fluid filled sacs in the joints
- The joint space is progressively lost over time.
How is diagnosis of OA carried out?
OA is diagnosed clinically without investigations if a person:
- Is 45 years or older and
- Has activity-related joint pain and
- Has either no morning-related joint stiffness or morning stiffness that lasts no longer than 30 minutes
What are treatment goals of OA?
- No cure - treatment aims to improve symptoms
- Increase mobility
- Decrease disability
- Releive pain
- Improve quality of life
Whar does management of OA involve?
Analgesia is main stay of OA (as per pain WHO ladder)
In addition to lifestyle advice such as increasing nuscle-strengthening and aerobic exercise and weightloss if overweight
What does the pharmacological management involve of OA?
- Non-steroidal anti-inflammatory drugs: e.g. ibuprofen, naproxen, diclofenac, celecoxib.
- Useful in reducing symptoms of OA following a trial of paracetamol.
- Topical NSAIDs should be trialed first, followed by oral NSAIDs on an ‘as required’ basis. Weak opioids (e.g. codeine) may be added in if needed.
- Different NSAIDs differ in potency, duration of action, side effects, and formulation.
What are the mode of action of non-selective NSAIDs?
What effects can this have?
Mode of action:
- Most act as non-selective inhibitors of cyclooxygenase, inhibiting both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) isoenzymes.
- This inhibits the formation of Prostaglandins and thromboxanes from Arachadonic acid - PG messenegr in inflammation, inhibitition of this inhibits inflammation
- COX-1 is present in most of the tissues in our bodies. In the GI tract, COX-1 maintains the normal lining of the stomach and intestines, protecting the stomach from the digestive juices.
- COX-2 is primarily found at sites of inflammation.
- Both COX-1 and COX-2 produce the prostaglandins that contribute to pain, fever, and inflammation, but since COX-1’s primary role is to protect the stomach and intestines and contribute to blood clotting, using drugs that inhibit it can lead to unwanted side effects.
What are the mode of action of COX-1 selective inhibitors and the effects?
COX-2 inhibitors (‘coxibs’):
- E.g. celecoxib and etoricoxib
- NSAIDs that directly target COX-2, reducing the risk of peptic ulceration.
- Higher risk of cardiovascular adverse effects due to inhibition of COX-2 in blood vessels, leading to a decrease of production of prostacyclin which may cause clot formation and hypertension.
- Prostacyclin normally prevents platlet aggregation and vasoconstiction
- Balance cardiovascular vs. GI risk.
What is prescribing advice which should be considered?
Prescribing advice:
- Is there an alternative to NSAID use?
- Paracetamol, lifestyle advice
- Start with a low dose and low risk NSAID for shortest time period
- Ibuprofen
- Only use one NSAID at a time
- increases side effects
- Is the patient already using an NSAID?
- Taking or buying (including topical)
- Does the patient require gastroprotection?
- PPI
- Is there a clinical need to monitor side-effects more closely?
- Elderly, complex med regime, multiple disease states
- Adverse effects
- GI bleed/ ulceration
- Thrombosis
- Renal faliure - inhibition of PGI2 and PGE2 leads to NA+ retention, renal blood flow decreased and renal impairement
- Contraindications
- Heart failure
- Renal faliure
- Severe hepatic impairment
- Hypersensitivity/ allergy to NSAID
- Current GI bleed, ulceration, perforation, obstruction
- Diclofenac CI in congestive HF, cerebrovascular disease, peripheral arterial disease, ischaemic heart disease
- Cautions
- IBD
- Renal impairment
- Elderly
- Drug interactions
- Corticosteriods (GI toxic med)
- ACE inhibitors/ diuretics (Renal toxic)
What increases risks of GI effects?
What should be prescibed?
Factors which increase the risk of GI effects:
- Using the maximum dose
- >65 years old
- History of gastroduodenal ulcer, GI bleeding or perforation
- Concomitant use of medications that are known to increase the risk of upper GI adverse events
- Serious co-morbidity
Should be co-prescribed with a proton-pump inhibitor (PPI) e.g. lansoprazole 15-30mg daily or omeprazole 20mg daily. If PPI inappropriate e.g. history of C.ff then H2RA
Non-pharmacological management of OA
- Weight loss
- Thermotherapy
- Electrotherapy - transcutaneous electrical nerve stimulation (TENS)
- Regular exercise (physiotherapy)
- Wearing suitable footwear
- Promoting good posture
- Use of special aids or devices to reduce the strain on your joints during your everyday activities
Surgical managmenet
When can this be given?
What is commonly done?
Patients with OA can be referred for surgical interventions if the following criteria is met:
- Patient has been offered core treatment options eg. Pharmacological management
- Patient experiences joint symptoms (pain, stiffness and reduced function) that have a substantial impact on their quality of life
Total knee and hip replacement surgeries – common but major surgeries.
