PCL 7 - Pharmacologic therapy for Osteoarthritis

The goals of management of patients with osteoarthritis(OA) are to control pain and swelling, minimize disability, improve quality of life, and educate the patient about his or her role in the management team. Management should be individualized to the patient’s expectations, level of function and activity, to the joints involved and the severity of the patient’s disease, to occupational and vocational needs, and to the nature of any coexisting medical problems. Subjective complaints and objective findings may guide the clinician in designing appropriate therapeutic goals.

PHARMACOLOGIC THERAPY
Simple analgesics
Pain relief is the primary indication for the use of pharmacologic agents in patients with OA who do not respond to non-pharmacologic interventions. In patients with non-inflammatory OA, this goal is generally achieved by the administration of a non-opioid, simple analgesic.
- Acetaminophen

Opioid analgesics
Should be avoided in long-term use due to increased sensitivity to adverse side effects, particularly sedation, confusion and constipation. However, these agents may be beneficial for short-term use in patients with acute exacerbations of pain.
- Codeine
- Oxycodone
- Propoxyphene

Non-steroidal anti-inflammatory drugs (NSAIDs)
NSAID use is often limited by toxicity. Among the side effects that can occur are;
- Rash and hypersensitivity reactions
- Abdominal pain and gastrointestinal bleeding
- Impairment of renal, hepatic and bone marrow function, and platelet aggregation
- Central nervous system dysfunction in the elderly

- Oral NSAIDs (e.g. ibuprofen, aspirin, naproxen)
- Topical NSAIDs (e.g. diclofenac)
- COX-2 inhibitors (e.g. -coxib)

Recommendations :
- A short-acting NSAID is generally used initially. Due to cost considerations, an over-the-counter agent is a reasonable choice. It usu takes about 2 to 4 weeks to evaluate the efficacy of NSAID
- If there is inadequate control with the initial dose, then the dose should be gradually increased toward the maximum for that drug. The patient should be educated to monitor for symptoms indicative of side effects.
- If one NSAID is not effective after 2-4 weeks on a maximal dosage, then another NSAID or non-acetylated salicylate should be tried.
- If there is a history of gastroduodenal disease, a selective COX-2 inhibitor may be considered in patients at low cardiovascular risk or a non-selective NSAID can be combined with antiulcer prophylaxis. When coxib use is considered, the patient should be informed of the potential cardiovascular risk.

Intraarticular Glucocorticoids
Intraarticular glucocorticoids injections may be appropriate in patients with OA who has one or a few joints that are painful despite the use of an NSAID, and in patients with monoarticular or pauciarticular inflammatory osteoarthritis in whom NSAIDs are contraindicated.
Intraarticular glucocorticoids slow cartilage catabolism and osteophyte formation in animals; they are also effective for short-term pain relief and can increase quadriceps strength after knee injection.