Exam 1 Osteoarthritis Flashcards
What is the pathophysiology of osteoarthritis?
- degenerative changes that occur in the cartilage and the associated bone
- characterized by increased destruction and subsequent proliferation of cartilage and bone
What is osteoarthritis considered as?
a wear and tear in the joint space
What is the incidence of osteoarthritis?
- observed more commonly in older patients
2. most common joint related disease → more common in females and severity of diseases increases with age
What joints are involved?
- distal interphalangeal joint (closer to nail bed)
- hips
- knees
What are risk factors of OA?
increased age, female, obesity, congenital defects, muscle weakness, repetitive stress (like athletes), major joint trauma, heredity → mechanical, genetic, metabolic, and inflammatory factors
What are clinical manifestations of OA?
- joint pain
- morning stiffness
- crepitus → popping noise in the joints
- inflammation
- muscle atrophy
- asymmetric involvement (not both joints at the same time) (RA is symmetric)
- no systemic systems
- instability of weight bearing joints
- Herberden’s nodes → the joint closer to nail
- Bouchard’s nodes → joint closer to the middle of finger
Differences between RA and OA
RA → any age, systemic involvement, inflammation present, bilateral (symmetric), morning stiffness of more than 1 hour, osteophyte absent, rheumatoid factor positive, symmetric swelling, malaise, fatigue, fever, musculoskeletal pain, subcutaneous nodules present
OA → older, localized to joint, absent inflammation, unilateral, morning stiffness for less than 30 minutes, osteophyte present, rheumatoid factor negative, subcutaneous nodules absent, irregular knobby swelling, deep aching pain
What are the goals of therapy for OA?
- relief of pain and discomfort
- maintain function of joint and strength
- prevent deformities
Drug therapy for OA is based on what?
location
What are the different types of drug therapy for OA?
- topical therapy
- oral agents
- supplements
- injectables
What are non-pharmacologic therapies?
- psychological support
- physical activity/exercise
- weight loss
- education (also important!!!)
- rest
- heat/ice
- physical therapy
- occupational therapy
What is the most important non-pharmacological treatment?
exercise of all joints for all locations!
What are examples of topical therapies?
menthol, camphor, oil of wintergreen (methyl salicylate), counterirritants like ICY HOT or Bengay
What is important to note about topical therapies?
dose is apply multiple times per day so there is poor compliance with patients in addition to the odor that some topicals have that patients dislike
What is capsaicin cream (Zostrix)?
- available as OTC
- mechanism of action → depletes substance P
- dose → apply sparingly to affected joints 2-4 times daily
- wait 2-4 weeks to evaluate results → poor compliance
- adverse effects → burning, stinging, and redness since it’s made from peppers
- NOT USED FOR HIP
What is diclofenac gel 1% Voltaren Gel?
- MOA → local inhibition of COX2 enzymes
- dose → apply to joint four times daily
- max 16g to any one joint daily
- not recommended in combination with systemic NSAIDs
- adverse effects → pruritus, burning, pain, and rash
- recently became OTC but was prescription before
- make sure patients know how to apply → 2-4 grams line then apply to joint and massage
What is diclofenac topical solution Pennsaid?
- for knee ONLY
- dose → 40 drops (40 mg) to each knee three times daily and apply 10 drops at a time OR 2 pumps (40 mg) twice daily
- local reaction most common adverse effect → itching, burning, rash
- has a garlic smell and taste → DMSO vehicle
- prescription
- apply to front. sides, and back of the knee
What is acetaminophen?
- MOA → inhibits synthesis of prostaglandins
- dose → max is 3-4 g per day
- need a 2-4 week trial as a scheduled dose for full effect → if no relief after 4 weeks, need alternative therapy
What is the true maximum of acetaminophen?
4 grams but OTC state 3 grams because other medications can have hidden acetaminophen (in scheduled 4-6 hour doses) → higher the dose, the higher risk of hepatotoxicity (especially with pre existing liver disease and heavy alcohol intake) → want to monitor liver function tests ALT/AST annually if on routine doses → but good for GI upset and won’t cause it
What is important to note about NSAIDs?
no 2 patients respond the same so if the patient doesn’t respond, switch to an alternative NSAID
What can affect NSAID choice?
adverse effects, costs, risk factors
What is NSAID mechanism of action?
inhibit COX enzymes
What is the dosing of an NSAID?
analgesic vs anti-inflammatory → most patients respond to analgesic dose (typically the smaller dose) → ex naproxen analgesic dose is 220 mg q 8-12 hours but anti-inflammatory dose is 440 mg q 8-12 hours → most patients start at analgesic dose first! → want to have 1-2 week trial for pain and 2-4 week trial if inflammation exists