Chapter 106: Osteoarthritis

UPDATE SUMMARY

The following updates to this chapter were made on March 2, 2021.

• Table 106-2: Diclofenac 1.5% solution removed due to market discontinuation.

• Diagnosis section under Clinical Presentation corrected to clarify that no palpable warmth may be indicative of clinical diagnosis of knee osteoarthritis.

• Dosing and Administration section for Topical NSAIDs updated to include additional patient counseling points and to remove discussion of 1.5% diclofenac solution

• Pharmacoeconomic Impact of NSAIDs section updated to include discussion on cost comparison of prescription only topical NSAIDs.

KEY CONCEPTS

• Osteoarthritis (OA) is a very common disease. OA prevalence increases with age and number of other chronic conditions, with women more commonly affected than men.

• Contributors to OA are systemic (age, genetics, hormonal status, obesity, occupational or recreational activity) and/or local (injury, overloading of joints, muscle weakness, or joint deformity).

• OA is primarily a disease of cartilage that reflects a failure of the chondrocyte to maintain proper balance between cartilage formation and destruction. This leads to loss of cartilage in the joint, local inflammation, pathologic changes in underlying bone, and further damage to cartilage triggered by the affected bone.

• The most common symptom associated with OA is pain, which leads to decreased function and motion. Pain relief is the primary objective of medication therapy.

• Manifestations of OA are local, affecting one or a few joints; the knees are most commonly affected, as well as the hips and hands.

• Nonpharmacologic therapy is the foundation of the treatment plan for all patients with OA. Nonpharmacologic therapy should be initiated before or concurrently with pharmacologic therapy.

• Based upon efficacy, safety, and cost considerations, scheduled acetaminophen, up to 4 g/day, should be tried initially for pain relief in knee and hip OA. If this fails, nonsteroidal anti-inflammatory drugs (topical or oral) are recommended, if there are no contraindications.

• Topical NSAIDs, in lieu of oral NSAIDs, are recommended for patients older than 75 years of age to decrease the risks of systemic toxicity.

• Strategies to reduce NSAID-induced GI toxicity include the use of nonacetylated salicylates, COX-2 selective inhibitors, or the addition of misoprostol or a proton pump inhibitor.

• Other agents useful in treating knee OA include intra-articular injections of corticosteroids, duloxetine, or tramadol.

Preclass Engaged Learning Activity

This activity is designed to build skills in developing a safe and effective patient specific plan as part of the patient care process.

Create a table of drug treatment options for the plan as part of the patient care process for a patient with knee, hip, and hand osteoarthritis in a patient with a history of a myocardial infarction, a patient with stage 3 chronic kidney disease, a patient ...