E2 L10: Osteoarthritis Flashcards
Osteoarthritis
Degenerative changes that occur in cartilage and the associated bone
-Characterized by increased destruction and subsequent proliferation of cartilage and bone
Factors affecting osteoarthritis:
Gender - more common in women
Hormones
Athleticism
Weight
Improper shift (too much weight on one side)
etc.
Incidence
Most common in older patients (85% of pt > 75 years)
Severity increases w/age
More common in females
Joints involved
Distal interphalangeal joint (fingers)
Hips
Knees
Risk factors
Increased age
Obesity
Congenital defects
Muscle weakness
Female
Repetitive stress
Major joint trauma
Heredity
Clinical manifestations
Joint pain
AM stiffness
Crepitus (cracking we hear when moving joints)
Inflammation
Muscle atrophy
Asymmetric involvement
Clinical manifestations cont.
No systemic symptoms (associated with joints)
Instability of weight bearing joints
Finger joint names
Heberden’s nodes
Bouchard’s nodes
Is there a cure for osteoarthritis?
No - surgery required
Common complaints
I have pain when I wake up
My knee is tender or sore after overuse
I feel pain in my knee even when I am not active
Getting up from a chair, out of a car, or going up or down stairs is difficult
I hear a crackling sound in my knee when I move
I experience a grating feeling in my knee when I move
The area around my knee is red and swollen
Goals of therapy w/osteoarthritis:
Relief of pain and discomfort
Maintain function of joint and strength
Treatment of OA - non drug therapy
Physiological support
Education (are they working out properly)
Rest
Physical activity / exercise
Heat/ice
Physical therapy
Occupational therapy
Weight loss
Treatment of OA - drug therapy
Topical therapy
Oral agents
Supplements
Injectables
Always start with non-drug therapy or drug therapy?
Non-drug
Two types of joints to treat for osteoarthritis
Hands
Knees and hips
Tx of OA: Topical therapy
Menthol
Camphor
Oil of wintergreen (methyl salicylate)
Topical, counterirritant
-Creates tingling in joints to distract from pain
Dose: apply to affected area TID-QID - not long acting
No systemic - no side effects
Topical therapy ex.
Bengay
Icy hot
Salonpas
Tx of OA: Topical therapy: Capsaicin Cream (Zostrix)
MOA: depletes substance P (pain receptor in skin)
Dose: apply sparingly to affected joints TID-QID
Wait 2-4 weeks of continuous application to evaluate results
Adverse effects: burning, stinging, and redness which dissipates w/continued use
Counterirritant
Tx of OA: Topical therapy: Diclofenac Gel 1% - Voltaren Gel
MOA - local inhibition of COX2 enzymes
Dose: Apply 2-4g to affected joint QID (2 to hands, 4 to knees)
Max 16g to any one join daily (total body max 32 grams/day)
NOT recommended in combo with NSAIDs
Adverse effects: burning, itching pain and rash
Tx of OA: Topical therapy: Diclofenac Topical Solution % - Pennsaid
For knee only
Dose:
40-drops (40mg) to each knee QID
Apply 10 drops at a time
2 pumps (40mg) twice daily
Local reaction most common adverse effect
-Not OTC
Only approved for knee
Hardly used
Acetaminophen (Tylenol)
MOA: not well defined, but is thought to involve the inhibition of prostaglandin synthesis in the CNS
Dose: Max 3-4 g per day
Two-four week trial
Why can you only take 3-4g of tylenol?
Increased chance of liver toxicity
Acetaminophen: Risks
Patient at risk for hepatotoxicity: Heavy EtOH intake
Pre-existing liver disease
Monitor ALT/AST annually if on routine doses (be mindful about hidden acetaminophen in combo products)
Tylenol Extra strength dosing: 500mg
Adults and children 12 years of age and over: Take 2 caps every 6 hours while symptoms last
DO NOT take more than 6 caps in 24 hours unless directed by a doctor
NSAIDs point to remember
No two patients respond the same
If patient does not respond - switch to alternative NSAID
NSAID MOA
Park’s lecture
NSAID therapy (Analgesic vs Anti-inflammatory dose)
Analgesic - Naproxen 220mg q 8-12 hrs
Anti inflammatory: Naproxen 440mg q8-12
Most patients respond to analgesic response
1-2 week trial for pain and 2-4 week trial if inflammation exists
NSAID therapy: adverse effects
GI upset, ulcers, bleeding, renal dysfunction, increase BP, increased risk of stroke, MI, and death
NSAIDs - at greatest risk for adverse effects:
Dose dependent
Age . 75
H/o GI bleed
h/o of PUD
Anticoagulants
Antiplatelet
Glucocorticoids
NSAID therapy: patients at greatest risk for nephrotoxicity
Nephrotoxicity: rapid deterioration in kidney function
-Patients with:
CHF
HTN
Renal Disease
Dehydration
NSAID therapy: patients at greatest risk for cardiovascular AE’s
CHF
CVD
Monitoring NSAIDS: what to look for
Blood pressure
Signs of edema or weight gain
SCr - every 3 months
Hgb / Hct - every 6-12 months
signs of dehydration
COX-2 inhibitors
COX-2 inhibitors
Celebrex
Dose: 100 - 200 mg orally daily or bid
Lower incidence of GI bleeding
Potential risks associated with COX-2 inhibitors
Increased risk of CV disease
Same effects on renal function
increase cost of therapy
Combination Products:
NSAID + PPI
-Vimovo - naproxen + esomeprazole
NSAID + misoprostol
-Arthotec - diclofenac + misoprostol
NSAID + H2 antagonist
Duexis - ibuprofen + famotidine
Know guidelines for NSAID use in OA
-
Opioid Analgesics:
Used PRN for breakthrough pain
Dosing: start low and go slow
Use long acting (SR) and short acting (IR)
Adverse effects of Opioid analgesics
Nausea
Somnolence (sleepy)
Constipation
Dizziness
Abuse potential
Tramadol (Ultram)
MOA: Affinity for µ receptor
Dose:
25-50 mg every 4-6 hrs
Titrate to 200-300 mg per day
Adverse effects:
Nausea, vomiting, dizziness, constipation
Duloxetine (Cymbalta)
Adjunct medication
Dose: 30mg/day x 1 week
Max dose: 60mg daily
AVOID with tramadol
Adverse effects: GI
OTC supplement Glucosamine/Chondroitin
MOA: stimulates proteoglycan synthesis
Dose; 500 mg PO TID (glucosamine)
400 mg PO TID (chondroitin)
Slow onset (4 weeks) - 3 month trial is adequate
Adverse effects: gas, bloating, cramping, nausea, and increased bleeding risk (glucosamine)
Treatment of OA: Intra-Articular Corticosteroid Injections:
Only used for isolated joints
No more than every 3-6 months
Actual injection can be quite painful, repeat injections can cause joint damage
Peak pain relief in 7-10 days
Treatment of OA: Hyaluronate Injection (Synvisc, Synvisc One)
MOA: temporary increase in viscosity
Dose:
Synvisc: injected into knee weekly for 3 weeks
Synvisc one: injected into knee once
Max benefit in 8-12 weeks
What is hyaluronate injection used for
Used for patients who do not tolerate other treatments or are not candidates for surgery
Only local adverse effects (minor swelling)
Treatment of OA: Joint Replacement Surgery
Relieves pain at rest
Restores function to the joint
Last 10-15 years
Newer materials last longer
Monitoring parameters with joint replacement therapy
Pain (at rest)
Joint stability and function
Risk of fall
Range of motion
X-rays
Degree of disability
Weight
ADRs from medications
Compliance with non-drug measures
QOL issues
Future/Alternative treatments
Acupuncture
Strategies/targets: cartilage, synovial membrane, subchondral bone
DMOAD - disease modifying osteoarthritis drugs
Stem cell therapy
