Pharmacologic Management of Osteoarthritis

First-Line Therapy: Acetaminophen

The American College of Rheumatology recommends acetaminophen (up to 4000 mg/day) as the preferred initial pharmacologic agent for mild-to-moderate OA pain due to its favorable safety profile, particularly regarding gastrointestinal, cardiovascular, and renal toxicity 1, 3.
Patients must be counseled to avoid all other acetaminophen-containing products to prevent exceeding the maximum daily dose 1.

The American College of Rheumatology recommends oral or topical NSAIDs at the lowest effective dose for the shortest duration necessary when acetaminophen provides inadequate relief 1, 6, 2.
For patients age 75 years and older, topical NSAIDs are strongly preferred over oral NSAIDs if acetaminophen fails 1.
For patients with GI bleeding risk, use either a COX-2 selective inhibitor or a nonselective NSAID plus proton pump inhibitor (PPI) if no GI bleed in past year 1.
For patients taking low-dose aspirin (≤325 mg/day) for cardioprotection, use a nonselective NSAID other than ibuprofen plus a PPI 1.

Intra-articular corticosteroid injections provide short-term pain relief (1-3 weeks) and are particularly indicated for acute exacerbations, especially with joint effusion 5, 7, 8.
Tramadol or duloxetine are conditionally recommended when patients have inadequate response to acetaminophen but cannot tolerate NSAIDs 1.
Topical NSAIDs demonstrate effect size of 0.91 versus placebo and are useful for patients unwilling or unable to take oral NSAIDs 5.
Topical analgesics or counterirritants (capsaicin cream, methyl salicylate, menthol) may benefit patients with mild-to-moderate pain 3.

Oral NSAIDs are contraindicated in CKD stage IV or V (eGFR <30 mL/min) 1.
COX-2 inhibitors are contraindicated in patients with increased cardiovascular risk 6.
Nonselective NSAIDs should be used with extreme caution in patients with cardiovascular disease or heart failure, as they may carry cardiovascular toxicity as a class effect 6.
Monitor for hepatotoxicity with chronic acetaminophen use, particularly in elderly patients where maximum dose reduction to 3 grams daily may be prudent 4.