Newer NSAIDs, such as celecoxib (Celebrex), are as effective as the older NSAIDs but cause fewer ulcers. (These newer drugs are called "Cox-II selective" because they primarily inhibit one enzyme called Cox-II, rather than inhibiting both Cox-I and Cox-II, as the older drugs do.) However, one study showed that for people at highest risk (those with recent bleeding ulcer), up to 10 percent of those treated with celecoxib developed a new ulcer; in addition, the risk was similar for these high-risk patients when taking an older drug (diclofenac) combined with a drug to protect the stomach (omeprazole). Just how safe these drugs are for the stomach in persons at lower risk of ulcers remains an area of some controversy and active research; current recommendations suggest reserving the Cox-II inhibitors for people at higher risk of ulcer disease (such as those who are also taking corticosteroids or who have had an ulcer in the past).

(Alert: Two of the COX-2 inhibitors have been withdrawn from the market — valdecoxib [Bextra] on April 7, 2005 and rofecoxib [Vioxx] in September 2004.)

Because aspirin has an anticoagulant effect — that is, because it inhibits the blood's ability to clot — people who take a lot of aspirin (or any of the older "nonselective" NSAIDs) may bleed or bruise easily. Other important side effects include kidney injury, allergic reactions, fluid retention and elevation of blood pressure. The cost of the different NSAIDs varies dramatically, from pennies per day to $2 per day or more; whether the differences in their side effect profiles are worth the added cost is often unclear.

For persons taking low-dose aspirin (for example, about 80 milligrams) for heart protection and another NSAID for pain, the aspirin should be taken first, at least an hour before the other NSAID so that the benefits to the heart will not be lost.

The most powerful anti-inflammatory agents are corticosteroids. These are synthetic versions of the body's hormone, cortisone, that are produced in small quantities by the adrenal gland. Synthetically produced corticosteroids are used to reduce inflammation and suppress activity of the immune system. The most commonly prescribed are prednisone and dexamethasone. Usually prescribed for short periods of time when inflammatory symptoms have not responded to other medications or during times of intense flare-ups, they may also be used when inflammation is severe and localized, especially at weight-bearing joints, such as the knee or ankle.

Taken orally or administered by injection, corticosteroids can produce dramatic improvement within a day or two. However, they have little lasting benefit and tend to become less effective over time. In addition, too many injections may damage the joint, and long-term use of oral corticosteroids often produces troubling side effects, such as weight gain, rounding of the face, high blood pressure, acne, easy bruising, cataracts, thinning of the skin and bone and an increased risk of diabetes and infection. When taken along with NSAIDs, there is a markedly increased risk of stomach ulcers.

Doctors generally prescribe a short course of corticosteroids to relieve acute symptoms and then gradually decrease the dosage. In all cases, the possible benefits are weighed against the possible side effects. And because side effects occur more frequently when corticosteroids are taken over long periods of time at high doses, these drugs are typically prescribed at the lowest effective dosage with ongoing efforts to reduce it further.

When a person does not respond to NSAIDs, or when the arthritis appears to be a result of an autoimmune disease, such as systemic lupus erythematosus or rheumatoid arthritis, disease-modifying antirheumatic drugs may be used. Many of these medications are actually borrowed from other diseases, such as cancer and malaria. Antimalarials include chloroquine (Aralen) and hydroxychloroquine (Plaquenil). Drugs considered to be even more powerful in these diseases include methotrexate (Rheumatrex), sulfasalazine, cyclosporine, azathioprine (Imuran) and cyclophosphamide (Cytoxan). All of these agents act to suppress inflammation, presumably through their effects on the immune system, and also have a risk of more serious side effects.

It may take weeks or even months before these drugs produce any beneficial effect. During the time it takes for these drugs to work, your doctor will likely recommend that you take an NSAID or a corticosteroid as well.

As with any medication, the disease-modifying antirheumatic drugs can have problematic side effects. Various drugs in this category can cause diarrhea, rashes, anemia (decrease in red blood cells), leukopenia (low white blood cell count) and increased risk of infection. In general, when a drug works by suppressing the immune system, there is an increased risk of infection. In addition, methotrexate can cause serious liver and lung problems. Some antimalarial drugs can affect the eyes. It is therefore necessary that use of these drugs be carefully monitored.

Gold salts, another disease-modifying antirheumatic drug, have been used to treat arthritis for more than half a century; however, the way in which they work is not entirely clear. It is rare now for physicians to prescribe gold. Recent advances in research and technology have yielded promising new anti-arthritis therapies, including leflunomide (Arava) and drugs that suppress the action of tumor necrosis factor (TNF). Leflunomide reduces the action of immune cells by impairing a protein required for DNA synthesis, whereas anti-TNF drugs seem to slow the destruction of the joints by disrupting the activity of TNF, a substance that promotes inflammation and joint damage. Examples of drugs that block the effects of TNF are etanercept (or Enbrel, injected under the skin once or twice a week), adalimumab (or Humira, injected under the skin once every two weeks) and infliximab (or Remicade, injected intravenously every four to eight weeks). Anikinra (Kineret) inhibits a different chemical mediator of inflammation called interleukin-1 (IL-1). Other injectable medications for rheumatoid arthritis include abatacept (Orencia), which prevents certain immune cells from causing inflammation, and rituximab (Rituxan), which acts against certain antibody-producing immune cells.

In one common form of arthritis, osteoarthritis, there is typically little or no inflammation. As a result, managing pain may be the primary focus of medical therapy. Pain relievers such as acetaminophen (Tylenol) may then be sufficient to control the pain. Other medications that may reduce symptoms of osteoarthritis include NSAIDs, other pain relievers, injected corticosteroids, or an injectable medication called hyaluronate (although its effects are modest).

Medical research is also looking into ways of restraining the body's autoimmune response before it is triggered, including efforts to develop a vaccine against arthritis.

Although much of conventional anti-arthritis medications are palliative, that is, they treat the symptoms, much of the newer research, and the therapies that hopefully will emerge, may provide much more substantial relief and perhaps even cure.