Drug Treatment For Osteoarthritis - Osteoarthritis: Arthritis Keeping Your Joints Healthy

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Drug treatment for osteoarthritis

Although no drug exists that will cure or reverse the progression of osteoarthritis, it is usually possible to alleviate pain and inflammation. Medications form the basis of treatment for osteoarthritis, but are best used in conjunction with other pain relief strategies, such as exercising to build your muscles and protecting your joints from injury or overuse (see "Slowing the progression of osteoarthritis").

Topical analgesics

Topical analgesics, which are applied to the skin, offer one alternative for mild pain relief. You can use these alone or in combination with one of the medications described below. Creams containing salicylate, such as Aspercreme or Bengay, and others containing capsaicin, such as Zostrix, are available over the counter. However, it's important to avoid touching any mucous membrane (for example, around the mouth, nose, or eyes) after applying the cream, to avoid irritation.

Mild pain relievers (analgesics)

To relieve the pain and stiffness of osteoarthritis, the first step is usually an over-the-counter pain reliever. Doctors often recommend acetaminophen (Tylenol) first because it's often effective for mild pain and easy on the stomach. But remember that acetaminophen, like any drug, has its own risks — especially for the liver.

A 2005 study in Hepatology concluded that acetaminophen was to blame for 42% of the cases of acute liver failure seen at hospitals during the study period. Many of these poisonings were accidental and occurred in people taking the drug regularly for pain relief.

To avoid an accidental poisoning, don't exceed the recommended maximum per day — generally set at 4 grams (4,000 milligrams), the equivalent of eight extra-strength Tylenol tablets. Remember that acetaminophen is often included in combination formulas, so it's important to read all medication labels carefully. If you drink more than a moderate amount of alcohol on a regular basis (more than two drinks a day for men, and one drink a day for women), it is wise to stay well below the maximum daily dose or avoid acetaminophen altogether, because your threshold for toxicity may be lower than it is for other people.

NSAIDs

It has become clear that nonsteroidal anti-inflammatory drugs (NSAIDs) may be more effective than acetaminophen in treating osteoarthritis because they not only relieve pain, but also reduce inflammation that contributes to pain, swelling, and stiffness.

The arsenal of NSAIDs has grown over the years to include about 20 different drugs. Among them are such well-known medications as aspirin, ibuprofen (Advil, Motrin, others), and naproxen (Aleve, Naprosyn, others). These drugs reduce pain and inflammation by blocking the production of prostaglandins, leukotrienes, and other chemical mediators. For many people, they are slightly more effective than Tylenol, especially during flare-ups of pain.

The most common side effects of these medications are stomach problems, including gastrointestinal bleeding and ulcers, often occurring without warning. That is because NSAIDs work by inhibiting both the COX-1 enzyme, which helps protect the stomach lining from the corrosive effects of stomach acids and digestive enzymes, and the COX-2 enzyme, which causes pain and inflammation. One widely quoted paper, published in the New England Journal of Medicine in 1999, estimated that each year these drugs contribute to at least 16,500 deaths and more than 100,000 hospitalizations in the United States. A study of people in Spain concluded that roughly one in three hospitalizations or deaths due to gastrointestinal bleeding could be attributed to NSAIDs. It is possible in many cases to avoid such complications — but first you and your doctor must work together to determine your risk of experiencing them.

The older you are, the higher your risk of developing bleeding and ulcers. Others at risk include people who have had ulcers in the past, people with rheumatoid arthritis, and people who are also taking a blood thinner or corticosteroids. Prolonged use and higher doses of NSAIDs also increase the risk. And some NSAIDs are more prone than others to causing ulcers; for example, aspirin (Anacin, Bayer, others) and indomethacin (Indocin) appear to have the highest risk.

If you are in a high-risk group, you should probably try to avoid NSAIDs if at all possible, and try other pain relief strategies. A COX-2 inhibitor is safer, but the risk isn't zero. If you're in a high-risk group and find that these other strategies don't work, then talk with your doctor about stomach-protecting drugs to take along with the NSAID. These include histamine blockers such as cimetidine (Tagamet) and ranitidine hydrochloride (Zantac), and proton pump inhibitors such as esomeprazole (Nexium), lansoprazole (Prevacid), and omeprazole (Prilosec). Another option is taking misoprostol (Cytotec) with the NSAID. Some medicines (such as Arthrotec or Prevacid NapraPAC) combine a medication that protects the stomach with an NSAID.

If taking NSAIDs produces stomach upset but not a bleeding ulcer, good initial strategies are to reduce the dose of the NSAID you're taking, try an entirely different pain reliever (such as acetaminophen), or switch to a drug that is more selective for COX-2. For example, celecoxib (Celebrex) is a COX-2 selective agent and might be better tolerated than indomethacin. Nabumetone (Relafen), although not officially a COX-2 selective agent, is also relatively selective for COX-2 and would be a better choice than indomethacin if stomach upset is a limiting factor. Other more selective medications to consider, as they may be more easily tolerated, are meloxicam (Mobic) and diclofenac (Voltaren).

No matter what your risk profile, to be on the safe side, use NSAIDs only under the supervision of your doctor, and do not combine NSAIDs with other medications without talking to your doctor first. Also take time at each doctor's visit to reassess the medications you are taking for your arthritis and to evaluate your symptoms. All too often, people are taking more medication than they really need. Other pain relief strategies might be used in combination with the drugs so you can lower the dose.

COX-2 inhibitors

In 1998, the FDA approved the first of a new generation of NSAIDs. Known as COX-2 inhibitors, these prescription drugs were designed to be more selective in their effects than traditional NSAIDs. COX-2 inhibitors, as their name implies, inhibit only the COX-2 enzyme involved in pain and inflammation, while sparing the COX-1 enzyme that protects the stomach lining. As such, they were able to relieve pain as well as the strongest NSAIDs, while causing less stomach irritation (although the risk of this side effect isn't eliminated).

Eventually the FDA approved three COX-2 inhibitors: celecoxib (Celebrex), rofecoxib (Vioxx), and valdecoxib (Bextra). But today only Celebrex is available in the United States, and it comes with a warning. The manufacturers took Vioxx and Bextra off the market after the FDA warned that these drugs could increase the risk of stroke and heart attack.

This is because both the COX-1 and COX-2 enzymes also exert effects on the arteries. The COX-1 enzyme narrows arteries and makes blood platelets sticky, while the COX-2 enzyme widens arteries. When just COX-2 is blocked, the "widen" signal is lost and the resulting combination of narrowed arteries and stickier platelets can lead to blood clots that block an artery in the heart, causing a heart attack, or one in the brain, causing a stroke.

For this reason, most people now choose to try other pain relief alternatives before taking the remaining COX-2 inhibitor on the market, celecoxib. If you do take this medication, talk with your doctor about how to take it safely, especially if you already have an increased risk of heart attack or stroke.

Corticosteroid injections

When osteoarthritis is accompanied by inflammation, as indicated by warmth and an accumulation of fluid in the joint, your doctor may remove a small amount of joint fluid and then inject a corticosteroid. This procedure can relieve inflammation quickly, but usually only for a short time. It is used almost exclusively for severe symptoms associated with these signs of inflammation, especially for osteoarthritis of the knee. This approach is usually used infrequently — up to three or four times per year — and only when absolutely necessary, because more frequent injections of these drugs may increase the risk of infection and can damage the joints.

Dietary supplements

The dietary supplements glucosamine sulfate and chondroitin sulfate are over-the-counter agents that may provide pain relief to people with moderate to severe pain from osteoarthritis (see "Glucosamine and chondroitin").

Hyaluronate injections

Injections of hyaluronate (Hyalgan, Synvisc) may provide mild relief of symptoms of knee osteoarthritis in some people. In its natural form, hyaluronate lubricates the joint and supplies it with nutrients. Synthesized forms of this chemical can be injected directly into an osteoarthritic knee once a week for three to five weeks. But the jury is still out on this approach: Some doctors do not believe the modest benefits are worth the risk and discomfort of the injections.

Last updated:	September 05, 2008