Medication Summary
The goals of pharmacotherapy in osteoarthritis are to reduce morbidity and to prevent complications. To date, no disease-modifying or structure-modifying intervention has been proved effective in osteoarthritis. Pay careful attention to a particular pharmacologic regimen’s adverse-event profile.
Pharmacologic agents used in the treatment of osteoarthritis include the following:
-
Acetaminophen
-
Nonsteroidal anti-inflammatory drugs (NSAIDs), oral and topical (eg, diclofenac topical)
-
Calcium channel blocker/COX-2 inhibitor combination
-
Intra-articular corticosteroids
-
Intra-articular sodium hyaluronate
-
Opioids
-
Duloxetine
-
Muscle relaxants
-
Nutraceuticals (eg, glucosamine/chondroitin sulfate)
Analgesics, Other
Class Summary
Pain control is essential to the management of osteoarthritis. The goals of treatment include pain alleviation and improvement of functional status.
Acetaminophen (Tylenol)
An initial trial with acetaminophen is warranted in patients with mild-to-moderate osteoarthritis symptoms who do not derive sufficient relief from nonpharmacologic measures. Acetaminophen is the drug of choice for patients who have a documented hypersensitivity to aspirin or NSAIDs, who have a history of upper gastrointestinal (GI) tract disease, or who are on anticoagulants.
Nonsteroidal Anti-inflammatory Drugs (NSAIDs)
Class Summary
NSAIDs have analgesic, anti-inflammatory, and antipyretic activities. They are used to relieve osteoarthritis pain when the clinical response to acetaminophen is unsatisfactory. The mechanism of action is nonselective inhibition of cyclooxygenase (COX)-1 and COX-2, resulting in reduced synthesis of prostaglandins and thromboxanes. Other mechanisms may also exist, such as inhibition of leukotriene synthesis, lysosomal enzyme release, lipoxygenase activity, neutrophil aggregation, and various cell-membrane functions.
In more inflammatory presentations of osteoarthritis, such as knee involvement with effusion, these agents may be used as first-line pharmacologic therapy. Use the lowest effective dose or intermittent therapy if symptoms are intermittent. All of these medications increase the risk for GI ulcers and have been associated with increased risk of cardiovascular disease. Patients at high risk for GI toxicity may consider adding misoprostol or a proton-pump inhibitor to the regimen or using a COX-2–specific NSAID.
The FDA approved a submicron low-dose product (Zorvolex) for osteoarthritis that allows treatment at a lower dose than the diclofenac sodium and potassium salts. Submicron diclofenac 35 mg PO TID significantly improved Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) pain subscale scores from baseline at 12 weeks (-44.1; P = 0.0024) compared with placebo (-32.5). [159]
Ketoprofen
Ketoprofen is indicated for relief of mild-to-moderate pain and inflammation. Small dosages are initially indicated in small and elderly patients and in those with renal or liver disease. Doses higher than 75 mg do not increase therapeutic effects. Administer high doses with caution, and closely observe the patient for response.
Piroxicam (Feldene)
Piroxicam decreases the activity of cyclooxygenase, which in turn inhibits prostaglandin synthesis. These effects decrease formation of inflammatory mediators.
Ibuprofen (Advil, Motrin IB, Caldolor, Neoprofen)
Ibuprofen relieves pain and inflammation. It is widely available and is relatively inexpensive as a generic drug. After the very early stages of osteoarthritis, inflammation begins to play a role in the disease. Thus, medications with a combination of analgesic and anti-inflammatory properties become more desirable, at least in theory.
Meloxicam (Mobic)
To some extent, meloxicam is more selective for COX-2 receptors than traditional NSAIDs are. It decreases the activity of cyclooxygenase, thereby, in turn, inhibiting prostaglandin synthesis. These effects decrease the formation of inflammatory mediators.
Diclofenac (Voltaren XR, Cataflam, Cambia, Zipsor)
Diclofenac is one of a series of phenylacetic acids that have demonstrated anti-inflammatory and analgesic properties in pharmacologic studies. It is believed to inhibit cyclooxygenase, which is essential in the biosynthesis of prostaglandins. Diclofenac can cause hepatotoxicity; hence, liver enzymes should be monitored in the first 8 weeks of treatment.
Diclofenac is rapidly absorbed; metabolism occurs in the liver by demethylation, deacetylation, and glucuronide conjugation. The delayed-release, enteric-coated form is diclofenac sodium, and the immediate-release form is diclofenac potassium. It poses a relatively low risk for bleeding GI ulcers.
Celecoxib (Celebrex)
Celecoxib is a COX-2–specific inhibitor. At therapeutic concentrations, COX-2 (inducible by cytokines at sites of inflammation, such as the joints) is inhibited, and COX-1 isoenzyme (present in platelets and the GI tract) is spared; therefore, in nonaspirin users, the incidence of GI toxicity (eg, endoscopic peptic ulcers, bleeding ulcers, perforations, and obstructions) is decreased in comparison with that seen in patients taking nonselective NSAIDs.
Naproxen (Aleve, Anaprox, Anaprox DS, Naprelan, Naprosyn)
Naproxen is used for relief of mild to moderate pain. It inhibits inflammatory reactions and pain by decreasing the activity of cyclooxygenase, which is responsible for prostaglandin synthesis. NSAIDs decrease intraglomerular pressure and decrease proteinuria.
Calcium Channel Blocker/COX-2 Inhibitor Combination
Class Summary
This combination provides blood pressure lowering affect from amlodipine to reduce the risk of fatal and nonfatal CV events, primarily strokes and myocardial infarctions.
Celecoxib/amlodipine (Consensi)
Celecoxib inhibits cyclooxygenase (COX)-2 which decreases formation of prostaglandin synthesis. Elicits analgesic, anti-inflammatory, and antipyretic properties. Amlodipine, a calcium channel blocker, Inhibits transmembrane influx of extracellular calcium ions across membranes of myocardial cells and vascular smooth muscle cells without changing serum calcium concentrations; this inhibits cardiac and vascular smooth muscle contraction, thereby dilating main coronary and systemic arteries. In clinical trials, the combination lowered diastolic and systolic blood pressure (both daytime and nighttime measurements) similarly to an equal dose of amlodipine. It is indicated in adults for whom treatment with both amlodipine for hypertension and celecoxib for osteoarthritis are appropriate.
Antidepressants, SNRIs
Class Summary
The selective serotonin-norepinephrine reuptake inhibitor (SNRI) duloxetine may be effective for reducing osteoarthritis pain.
Duloxetine (Cymbalta)
Potent inhibitor of neuronal serotonin and norepinephrine reuptake. Indicated for chronic musculoskeletal pain, including discomfort from osteoarthritis and chronic lower back pain.
Analgesic, Topical
Class Summary
Topical analgesics are used for osteoarthritis involving relatively superficial joints, such as the knee joint and the joints of the hands. They are much less effective for deeper joints, such as the hip joint.
Capsaicin (Qutenza)
Capsaicin is a topical analgesic of choice in osteoarthritis. Derived from plants of the Solanaceae family, it may render skin and joints insensitive to pain by depleting substance P in peripheral sensory neurons. Capsaicin must be used for at least 2 weeks for the full effects to be appreciated.
Opioid Analgesics
Class Summary
Opioid analgesics are used in patients whose pain has not been controlled with weaker analgesic medications. They are a particularly reasonable choice in patients who do not want joint-replacement surgery, are too medically ill for joint replacement, are not candidates for joint replacement for other reasons, or are trying to buy time for subsequent joint-replacement surgery.
Elderly patients (aged 65 years and older) with arthritis are more likely to incur a fracture when initiating opioid therapy as opposed to NSAID therapy. A higher opioid dose is associated with a greater risk of fracture; this risk is due to an increased risk of falls. During the first 2 weeks after initiation of opioid treatment, short-acting opioids are associated with a greater fracture risk than long-acting opioids are. [160]
Tramadol (Ultram, Ultram ER, ConZip)
Tramadol inhibits ascending pain pathways, altering perception of and response to pain. This agent also inhibits the reuptake of norepinephrine and serotonin.
Oxycodone (OxyContin, Roxicodone)
Pure narcotic analgesics, such as oxycodone, might be the initial drug of choice. Eventually, this short-acting narcotic can be replaced with a long-acting transdermal preparation, such as fentanyl (Duragesic patch).
Corticosteroids
Class Summary
Intra-articular pharmacologic therapy includes corticosteroid injection and viscosupplementation. Steroid injections generally result in a clinically and statistically significant reduction in osteoarthritic knee pain as soon as 1 week after injection. The effect may last, on average, anywhere from 4 to 6 weeks per injection, but the benefit is unlikely to continue beyond that time frame. However, triamcinolone acetonide extended-release injectable suspension (Zilretta) may reduce pain intensity for up to 12 weeks.
Triamcinolone acetonide extended-release injectable suspension (Zilretta)
Corticosteroid with anti-inflammatory and immunomodulating properties. It binds to and activates the glucocorticoid receptor, leading to activation of anti-inflammatory transcription factors (eg, lipocortins). It also inhibits inflammatory transduction pathways by blocking arachidonic acid release and preventing prostaglandin and leukotriene synthesis. Indicated for management of osteoarthritis knee pain. Administered as a single intra-articular injection. Not intended for repeat administration.
Triamcinolone acetonide injectable suspension (Kenalog-40)
Corticosteroid with anti-inflammatory and immunomodulating properties; it binds to and activates the glucocorticoid receptor, leading to activation of anti-inflammatory transcription factors (eg, lipocortins); it also inhibits inflammatory transduction pathways by blocking arachidonic acid release and preventing prostaglandin and leukotriene synthesis. Indicated for intra-articular injection for pain management of osteoarthritis.
Methylprednisolone (Depo-Medrol, Medrol, Solu-Medrol, A-Methapred)
Methylprednisolone decreases inflammation by suppressing migration of polymorphonuclear leukocytes (PMNs) and reversing increased capillary permeability.
Betamethasone (Celestone Soluspan)
Betamethasone decreases inflammation by suppressing migration of PMNs and reversing increased capillary permeability. It affects the production of lymphokines and has an inhibitory effect on Langerhans cells.
Antirrheumatic, Miscellaneous
Class Summary
Intra-articular injections of these agents are used to treat patients with osteoarthritic knee pain that is unresponsive to conservative nonpharmacologic therapy and simple analgesics (eg, acetaminophen).
Sodium hyaluronate (Euflexxa, Hyalgan, Orthovisc, Supartz, Synvisc, Synvisc-One)
Sodium hyaluronate is a biological polysaccharide that supports the lubricating and shock-absorbing properties of articular cartilage.
Skeletal muscle relaxants
Class Summary
The use of certain skeletal muscle relaxants have been shown to be helpful in osteoarthritis.
Carisoprodol (Soma)
Short-acting medication that may have depressant effects at spinal cord level.
Skeletal muscle relaxants have modest short-term benefit as adjunctive therapy for nociceptive pain associated with muscle strains and, used intermittently, for diffuse and certain regional chronic pain syndromes. Long-term improvement over placebo has not been established.
Dantrolene (Dantium, Revonto)
Acts peripherally at muscle fiber rather than at neural level; reduces muscle action potential–induced release of calcium and also affects intrafusal and extrafusal fibers and spindle sensitivity. Has no action on smooth or cardiac muscle tissue. Induces release of Ca++ into sarcoplasmic reticulum, subsequently decreasing the force of excitation coupling. Only drug that intervenes at a muscular level. Preferred for the cerebral form of spasticity. Less likely to cause lethargy or cognitive changes like baclofen or diazepam.
May reduce painful cramping and detrimental muscle tightening.
Can be administered PO/IV. IV form is much more expensive and should be reserved for patients unable to take oral medications. Most patients respond to 400 mg/day or less. Eliminated in the urine and bile.
Baclofen (Lioresal)
Muscle relaxant (central), presynaptic GABA-B receptor agonist that may induce hyperpolarization of afferent terminals and inhibit both monosynaptic and polysynaptic reflexes at spinal level. Lessens flexor spasticity and hyperactive stretch reflexes of upper motor neuron origin. Eliminated through renal excretion.
Well absorbed, with average oral bioavailability of 60% and mean elimination half-life of 12 h; steady state reached within 5 d with multiple dose administration; metabolism occurs in liver (P 450-dependent glucuronidation and hydroxylation); 6 major and a few minor metabolites produced.
-
Anteroposterior (AP) radiograph of the hip reveals severe superior migration of the femoral head (which reflects loss of articular cartilage), subchondral sclerosis, prominent osteophytes, and a large Egger cyst in the superior acetabulum. Mild flattening of the superior aspect of the femoral head is present.
-
Osteoarthritis of the elbow is not commonly seen; however, it can occur with a history of previous trauma.
-
Osteoarthritis of the elbow is not commonly seen; however, it can occur with a history of previous trauma.
-
Osteoarthritis of the elbow is not commonly seen; however, it can occur with a history of previous trauma.
-
This radiograph demonstrates osteoarthritis of the right hip, including the finding of sclerosis at the superior aspect of the acetabulum. Frequently, osteoarthritis at the hip is a bilateral finding, but it may occur unilaterally in an individual who has a previous history of hip trauma that was confined to that one side.
-
Arthroscopic view of a torn meniscus before (top) and after (bottom) removal of loose meniscal fragments.
-
Arthroscopic view of an arthritic knee.
-
Arthroscopic view of a knee after the removal of loose fragments of articular and meniscal cartilage.
-
Arthroscopic view of the removal of cartilaginous loose body.
-
Anteroposterior radiograph shows knee replacement in 1 knee and arthritis in the other, with medial joint-space narrowing and subchondral sclerosis.
-
Anteroposterior radiograph of the pelvis and hips shows an arthritic hip not treated surgically and a total hip replacement.
-
Anteroposterior radiograph obtained after knee replacement.
-
Lateral radiograph obtained after knee replacement (same patient as in the above image).
-
Oblique projection demonstrates gradual narrowing and sclerosis of the facet joints as one progresses down the lumbar spine.
-
Standing radiograph of the knee reveals narrowing of the medial and lateral femorotibial compartments with marginal osteophytes.
-
H&E stain, high power magnification showing clusters of chondrocytes (center) that is a proliferation known as "chondrocyte cloning". Image courtesy of Francis Gannon, MD.
-
H&E stain, medium power magnification showing numerous vertical slits (upper left) in the articular surface cartilage known as "fibrillation" with increase in eosinophilia of the remaining cartilage due to loss of proteoglycans. Image courtesy of Francis Gannon, MD.
-
Gross photograph of external (top) and cut surface (bottom) showing areas of complete loss of articular cartilage with peripheral osteophytes formation. Image courtesy of Francis Gannon, MD.