Osteoarthritis

Question 1

Define OA

Answer 1

Chronic non-inflammatory degenerative arthropathy due to damage and degradation of joint cartilage.

Typified by 4 signs seen on x-ray (see next slide)

Commonly affects small joints of hands, knees and hip, as well as spine

May be primary - e.g. nodal arthritis

Secondary - e.g. previous trauma, infection, inflammatory arthropathy

Question 2

OA epidemiology

X-ray features (4)

Answer 2

75% of people >70

1. Joint space narrowing
2. Osteophytes
3. Bone cysts
4. Subchondral sclerosis (thickening)

Question 3

Alternatives in non-pharm management

Answer 3

Weight loss

Lifestyle changes; quit smoking

Physio - muscle strengthening and try to maintain mobility

OT - cane, aids at home e.g. jar opening

Question 4

What are principles of management medically?

What adjunctive therapies are there?

Answer 4

Pain relief to maintain as much function as possible; Follow WHO analgesic ladder, only using opioids as last resort (with caveat of side-effects of all these drugs)

INtra-articular steroids (up to 4x a year); ? role for Vitamin C. Capsaicin Cream can reduce analgesia dependence but takes up to 4 months to act

Question 5

What are non-selective NSAIDs?

Give examples

What is drawback?

Answer 5

COX-1 and COX-2 inhibitors (non-specific). Non-expensive but risk of renal problems and interactions with warfarin.

1. Aspirin
2. Ibuprofen
3. Naproxen - lowest risk GI bleed
4. Diclofenac
5. Piroxicam
6. Indomethacin
7. Ketorolac

• Risk of GI bleed - 12000 annually attributable to NSAIDs
• Unnopposed leukotriene action can lead to bronchoconstriction -> risk with asthma

Question 6

How do selective NSAIDs differ?

Drawbacks?

Examples

Answer 6

Only inhibit COX-2 (articular inflammation) - supposed to have less GI side effects because COX1 is the gastro protective enzyme.

More expensive and increased cardiovascualr risk due to unopposed pro-thrombotic effects of COX-1 mediated TXA2

1. Celecoxib
2. Etoricoxib
3. Meloxicam
4. Etodolac

Question 7

Cautions in NSAID prescribing?

Contraindications?

Side effects?

Answer 7

• Elderly, pregnant (miscarriage and early closure of DA), breastfeeding, clotting disorder, renal/cardiac/hepatic impairment
• Severe heart failiure, previous or active peptic ulceration, hypersensitivity
• GI (NVD, dyspepsia), hypersensitivity, heaptic damage, photosensitivity, fluid retention, raised BP, H, depression etc etc etc