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
What are adverse effects of NSAIDs?
GI upset, ulcers, bleeding, renal dysfunction, increased BP, increased risk of stroke, MI, and death
Who are at greatest risk for adverse effects?
is dose dependent but those over 75, history of GI bleed, history of PUD, anticoagulants, antiplatelets, and glucocorticoids (have increased risk of bleeding)
Which dose has higher risk of adverse effects?
anti-inflammatory dose
What patients are at greatest risk for nephrotoxicity?
CHF, HTN, renal dysfunction, dehydration
What patients are at greatest risk for cardiovascular adverse effects?
- CHF
2. CVD
What is the importance of knowing the score?
is a risk assessment tool that assesses their age, gender, and risk factors and the score gives a number to see if it’s okay to go ahead with the use of NSAID therapy
How do you monitor NSAIDs?
- blood pressure → since NSAIDs can increase BP
- signs of edema or weight gain
- BUN/SCr every 3 months → kidney function tests
- Hgb/Hct every 6-12 months → to see increased risk of bleeding
- signs of dehydration
What is an example of a COX 2 inhibitors?
Celebrex (celecoxib) with the dose of 100-200 mg orally daily or bid → has lower incidence of GI bleeding because it only inhibits COX2
What are potential risks associated with COX2 inhibitors?
- increased risk of cardiovascular disease → patients with history of MI should not take NSAIDs
- increase cost of therapy
- same effects on renal function
What are combination products used for osteoarthritis?
- NSAID + PPI → vimovo - naproxen + esomeprazole
- NSAID + misoprostrol → arthrotec - diclofenac + misoprostol
- NSAID + H2 antagonist → duexis - ibuprofen +famotidine
Combination products contain what?
a gastro=protective agent which can decrease risk of ulceration and GI bleeding
When are opioid analgesics used?
- used as needed for breakthrough pain and when patients fail the other topical or oral products → used when bone on bone and patient is in significant pain (later in disease or if surgery is not an option)
- dosing → start low and go slow, can use long acting (SR) and short acting (IR)
- adverse effects → nausea, somnolence, constipation, dizziness
What is tramadol?
- MOA → affinity for mew receptor and inhibits norepinephrine and serotonin by affinity of the mew receptor
- dose → 25-50 mg every 4-6 hours and can titrate to 200-300 mg per day per patient response
- adverse effects → nausea, vomiting, dizziness, constipation
What is duloxetine?
- adjunct medication
- dose is 30 mg/day for 1 week
- max dose is 60 mg/day
- avoid with tramadol
- adverse effects → gastrointestinal (nausea, vomiting, constipation)
Why should you not start a patient on duloxetine?
has neuropathic and musculoskeletal impact
Most patients use what medication?
NSAIDs and acetaminophen
What is glucosamine/chondroitin?
- an OTC supplement that stimulates proteoglycan synthesis
- dose → 500 mg PO TID (glucosamine) or 400 mg PO TID (chondroitin) → need to take on scheduled basis
- has slow onset (4 weeks) but 3 month trial is adequate
- adverse effects → gas, bloating, cramping, nausea, and potential for insulin resistance (concern with patients with diabetes, HTN, increased lipids)
How are intra-articular corticosteroid injections used to treat osteoarthritis?
- only used for isolated joints
- no more than every 4-6 months
- actual injection can be quite painful
- peak pain relief in 7-10 days
- used when patients are not candidates for surgery or joint space replacement or is waiting for one
How are hyaluronate injections used?
- MOA → temporary increase in viscosity (in the joint space)
- dose → injected into joint weekly for 3-5 weeks
- maximum benefit in 8-12 weeks
- used for patients who do not tolerate other treatments or are not candidates for surgery
- only local adverse effects (minor swelling) and pain at injection site
How does joint replacement surgery work?
- relieves pain at rest
- restores function to the joint
- lasts 10-15 years and maybe even longer now with newer materials
- most patients and all patients will need it (just a matter of time in terms of progression of the disease and the bone on bone)
- only used for the weight bearing joints → knees and hips
What are some monitoring parameters?
- pain (at rest)
- joint stability and function
- risk of fall
- range of motion
- X rays
- degree of disability
- weight → increased weight can increase risk
- ADRs from medications (especially with oral products)
- compliance with non drug measures
- QOL issues
What are some future alternative treatments?
- acupuncture (non-pharmacologic)
- strategies/targets → cartilage, synovial membrane, subchondral bone
- DMOAD → disease modifying osteoarthritis drugs (not currently in use)
- stem cell therapy
What is the greatest concern when starting a patient on acetaminophen?
hepatic toxicity → want to educate patient on how to properly take it
If wanting to use oral NSAIDs, what do we want to measure?
a patient’s GI and cardiovascular risk → if use NSAID, can add a PPI for gastroprotection
What is the treatment of OA?
step 1 is non drug therapy (FOR EVERYONE) → then decisions based on type of OA (knee/hip or hands) and risk factors
What is knee/hip treatment?
- is acetaminophen contraindicated? yes → alternative first line agents like topical NSAIDs (knee only) and/or intra-articular corticosteroids and/or tramadol and/or oral NSAIDs ( if less than75 and low CV and GI risk) → if effective continue treatment, if not, use alternative second line like opioid, surgery, duloxetine (knee only) or hyaluronate injection
- is acetaminophen contraindicated? no → acetaminophen max 4 g/day → is it effective? → yes continue treatment, no use alternative second line agent
What is hand treatment?
- is patient less than 75? yes → first line agents like topical NSAIDs or topical capsaicin and/or tramadol → is it effective? → yes then continue treatment but if no, use alternative regimens such as combined therapy with two first line agents (aka topical NSAID and tramadol)
- is patient less than 75? → no then use first line agent such as oral NSAID (if low GI and CV risk) or topical NSAID or topical capsaicin and/or tramadol → is treatment effective? → yes then continue, no then alternative regimen like combined therapy
Is electric nerve stimulation recommended?
no → it is strongly against for hand, knee, and hip
What are non-pharmacologic treatments?
education, self management, and exercise are important regardless of joint space impacted → weight loss for knee/hip
Topical NSAIDs are used for what?
knee and hand
Where are oral NSAIDs recommended for?
across all joint spaces
Intra-articular corticosteroids are used for what locations?
knee and hip
Acetaminophen, tramadol, and duloxetine are used for what joint spaces?
all joint spaces
When recommending treatment, what do you want to consider?
- non-pharmacologic treatments
- medication history
- co-morbidities
- risk factors for adverse effects
What topicals are used multiple times a day?
menthol, camphor, oil of wintergreen (methyl salicylate), counterirritants, capsaicin cream, diclofenac gel, diclofenac topical solution
