Osteoarthritis

Question 1

OA Risk Factors

Answer 1

• age, gender
• genetic predisposition
• occupational and recreational activities w/ repetitive motion
• hx of joint trauma
• obesity

Question 2

Pathophys of OA

Answer 2

• loss of cartilage in joint
• local inflammation
• pathologic changes in underlying bone

Question 3

OA Clinical Presentation

Answer 3

• pain typically worse with use, relieved w/ rest (early OA)
• morning stiffness and “gelling” of joints
• bony enlargement, crepitus on motion and limited joint motion

Question 4

Tx Goals

Answer 4

• educate pt and caregivers
• relieve pain and stiffness
• maintain or improve joint mobility
• limit functional impairment
• preserve joint integrity
• maintain or improve QOL

Question 5

Non-Pharm Therapy

Answer 5

• pt education
• strengthening and ROM exercises (PT)
• use of assistive devices (OT)
• joint protection
• weight loss as needed
• surgery

Question 6

What is pharm therapy used for in treating OA?

Answer 6

• used only for symptom management

- meds do not change the course of dz

Question 7

APAP Regimen

Answer 7

• up to 4 gm/day

- reduce dose by 50-75% for renal or hepatic failure or EtOH abuse

Question 8

APAP Advantages

Answer 8

• effective for mild to moderate pain

- low risk of AEs

Question 9

APAP Disadvantages

Answer 9

• not effective for pain assoc. w/ inflamation

- use w/ caution for pts with hepatic dysfunction

Question 10

N-NSAIDs Advantages

Answer 10

-effective for moderate to severe pain

Question 11

N-NSAIDs Disadvantages

Answer 11

• GI side effects
• renal dysfunction
• precautions: renal failure, CHf, HTN

Question 12

Drug Interactions of APAP

Answer 12

• warfarin: increased risk of bleeding (does not change INR)
• diuretics, ACEIs, ARBs: may decrease effect (b/c NSAIDs can increase BP)
• lithium: increases Li levels

Question 13

Why should indomethacin be avoided with hip OA?

Answer 13

long term use assoc w/ accelerated joint destruction in this setting

Question 14

Use of Diclofenac Gel

Answer 14

• topical NSAID

- recommended for pts > 75

Question 15

Nonacetylated Salicylates Regimen

Answer 15

• salsalate 500-750 mg BID

- choline magnesium trisalicylate 500-750 mg TID

Question 16

Nonacetylated Salicylates Advantages

Answer 16

• effective for mod to severe pain
• less risk of GI toxicity compared to other N-NSAIDs
• do not affect platelet aggregation

Question 17

Nonacetylated Salicylates Disadvantages

Answer 17

• potential for GI adverse effects, renal dysfunction

- use w/ caution for pts with renal failure, CHF, HTN

Question 18

Nonacetylated Salicylates Drug Interactions

Answer 18

• warfarin
• diuretics, ACEIs, ARBs: decreased effect
• lithium: increased Li levels

Question 19

COX-2 Inhibitor Regimen

Answer 19

celecoxib 100 mg BID or 200 mg qday

Question 20

COX-2 Inhibitor Advantages

Answer 20

• effective for mod to severe pain
• less risk of GI toxicity compared to N-NSAIDs
• do not affect platelet aggregation

Question 21

COX-2 Inhibitor Disadvantages

Answer 21

• potential for GI adverse effects, renal dysfunction
• use w/ caution for pts with renal failure, CHFl, HTN
• CI in pts with allergy to sulfa products
• possible increased risk of CV events

Question 22

COX-2 Inhibitor Drug Interactions

Answer 22

• warfarin
• diuretics, ACEIs, ARBs: decreased effect
• lithium: increased Li levels

Question 23

When should COX-2 use be considered?

Answer 23

-pts with high GI risk and low CV risk

Question 24

Tramadol Category

Answer 24

1/3 mu receptor agonist, 2/3 SNRI

Question 25

Tramadol Regimen

Answer 25

50-100 mg q4-6hr (max 400 mg/day, 300 for geriatric)

Question 26

Tramadol Disadvantages

Answer 26

- sedation, confusion, seizures - urinary incontinence - adjust dose to q12hr for CrCl < 30 ml/min

Question 27

When should tramadol use be considered?

Answer 27

- for mod to severe pain | - no response, AEs or CIs to APAP and NSAIDs

Question 28

Intraarticular Steroids Regimen

Answer 28

- various | - methylprednisolone 4-80 mg q1-5 weeks based on joint size

Question 29

Intraarticular Steroids Advantages

Answer 29

-effective for knee OA

Question 30

Intraarticular Steroids Disadvantages

Answer 30

-not effective for hip OA

Question 31

Intraarticular Hyaluronic Acid Regimen

Answer 31

-Hyalgan, Synvisc, Supartz

Question 32

Intraarticular Hyaluronic Acid Advantages

Answer 32

-duration of relief may last up to 6 months

Question 33

Intraarticular Hyaluronic Acid Disadvantages

Answer 33

- delated onset of action - not approved for hip OA - some clinical trial results similar to placebo - use w/ caution if allergies to avian proteins and egg products

Question 34

Duloxetine/Cymbalta Indication

Answer 34

indicated for chronic musculoskeletal pain 2ary to lower back pain and OA

Question 35

Duloxetine/Cymbalta Regimen

Answer 35

- start at 30 mg/day x 1 week to decrease nausea | - do not exceed 60 mg/day for pain

Question 36

When should Duloxetine/Cymbalta be considered?

Answer 36

if analgesics are not sufficient and there is concurrent depression

Question 37

Opioids Disadvantages

Answer 37

- constipation, sedation, confusion | - meperidine not recommended due to accumulation in the elderly

Question 38

Topical Capsaicin MOA

Answer 38

-releases and depletes substance P from nociceptive pain nerve fibers

Question 39

Topical Capsaicin Regimen

Answer 39

-apply to symptomatic joint TID-QID

Question 40

Topical Capsaicin Advantages

Answer 40

-avoid systemic side effects

Question 41

Topical Capsaicin Disadvantages

Answer 41

- local irritation/burning sensation - delayed response up to 2 weeks - nonadherence - no recommended for knee OA

Question 42

Glucosamine Sulfate +/- Chondroitin Regimen

Answer 42

500 mg PO TID

Question 43

Glucosamine Sulfate +/- Chondroitin Disadvantages

Answer 43

- potential allergic reaction in pts with shellfish allergy - may cause GI upset and nausea - not recommended for hip or knee OA

Question 44

Which pharm options does the College of Rheumatology recommend using for hip and knee OA?

Answer 44

- APAP - oral or topical NSAIDS - tramadol - intraarticular corticosteroid injections

Question 45

Which pharm options does the College of Rheumatology NOT recommend using for hip and knee OA?

Answer 45

- chondroitin sulfate - glucosamine - topical capsaicin