Psoriatic arthritis (PsA) — a condition characterized by joint pain, swelling, and stiffness resulting from inflammation due to an overactive immune system — is commonly managed with a variety of treatment options. Most people with the condition use disease-modifying antirheumatic drugs (DMARDs) such as leflunomide, sold under the brand name Arava.

Medications like nonsteroidal anti-inflammatory drugs (NSAIDs) can help relieve symptoms such as pain and swelling, but they don’t affect the underlying processes that cause PsA. DMARDs, on the other hand, calm the immune system. This reduces inflammation, protects the joints from being attacked by immune cells, and prevents PsA from getting worse and causing additional damage.

What Is Leflunomide, and How Does It Work?

The U.S. Food and Drug Administration (FDA) approved leflunomide in 1998 as a treatment for rheumatoid arthritis, a related inflammatory disease. Although not specifically approved for PsA, leflunomide is often recommended for treating the condition because it can help treat joint swelling and pain.

Leflunomide blocks a cell’s ability to divide and create new cells. In particular, it prevents white blood cells in the immune system from dividing. Because these cells are responsible for inflammation, leflunomide holds back the immune system to help prevent inflammatory processes.

Leflunomide’s immune-weakening effects can help control PsA, but they can also make it harder for your body to fight off infections. While using leflunomide, you should try to protect yourself from germs by regularly washing your hands and staying away from others who are sick. Tell your doctor if you experience symptoms of infection, including:

• Fever
• Cough
• Sore throat
• Red, discolored, or tender skin
• Painful or frequent urination

When Is Leflunomide Used?

Your rheumatologist may recommend a DMARD if your joints have been inflamed for more than six weeks. Most people take DMARDs along with NSAIDs.

You may be able to choose between multiple DMARDs. Leflunomide, along with drugs such as methotrexate (sold as Otrexup, Rasuvo, and Trexall) and sulfasalazine (Azulfidine), is a type of conventional DMARD. The medications have been used for a long time to help slow down PsA. In more recent years, researchers have developed other types of DMARDs, including biologics and targeted synthetic DMARDs.

Conventional DMARDs like leflunomide weaken the overall immune system by blocking many types of immune cells. These drugs are often the first treatments prescribed for PsA. If conventional DMARDs don’t work well for you, your doctor may suggest switching to a biologic, which inhibits specific types of proteins or cells in the immune system. Biologics are more expensive than leflunomide and similar DMARDs, and they may require giving yourself an injection or going to a health care professional’s office for IV treatment.

Is Leflunomide Effective for Psoriatic Arthritis?

Although not as common as methotrexate, leflunomide is used by many people with PsA to help control their condition. Research has found that, for those with PsA, leflunomide can help improve:

• Joint tenderness or swelling
• Pain
• Tiredness
• Skin lesions such as plaques (patches of dry, itchy, scaly skin)
• Dactylitis (swollen fingers or toes)
• Nail symptoms, including pitting or discoloration

In one small PsA study, researchers reported that nearly half of participants had improvements in their condition one year after starting leflunomide.

A recent clinical trial also found that taking leflunomide with methotrexate controlled PsA better than methotrexate alone, although the combination did lead to more side effects.

Taking Leflunomide

Leflunomide comes in the form of tablets that are taken by mouth. You can buy the name-brand pills, Arava, or use a generic version.

Your doctor will determine the dose of leflunomide that is most appropriate for you based on your condition and overall health. In general, you’ll take a high dose — often 100 milligrams — the first couple of days, and then lower the dose. Make sure to use leflunomide as instructed by your doctor.

Leflunomide won’t immediately help with your symptoms. It may be several weeks or months before you know whether it is working to control your PsA. In the meantime, NSAIDs can reduce PsA symptoms.

Does Leflunomide Cause Side Effects?

While using leflunomide for PsA, you may experience common side effects, including:

• Heartburn
• Nausea or vomiting
• Diarrhea
• Lightheadedness or weakness
• Headache
• Hair loss
• Dry skin
• Unexpected weight loss
• Muscle aches or cramps
• Numbness, pain, or tingling

Leflunomide also sometimes causes more serious side effects. These may include hives (small, itchy bumps), blisters, mouth sores, a skin rash, shortness of breath, or a cough. These side effects are rare, but tell your doctor if you experience them.

Other Potential Safety Concerns

For some people who have PsA, leflunomide may not be a good fit. That includes those with other health conditions, such as diabetes, kidney disease, severe liver disease, and tuberculosis, as well as conditions that affect the blood or bone marrow or weaken the immune system. Talk to your doctor about whether leflunomide may be safe for you based on your overall health.

Be aware that leflunomide may damage your liver, especially if you drink alcohol or use medications or supplements such as acetaminophen (Tylenol), cholesterol medications, or supplements that contain iron or niacin (vitamin B3). Your doctor may want to periodically assess your liver function with blood tests that measure your liver enzymes.

In addition, leflunomide can harm unborn babies or cause birth defects. This medication should be avoided during pregnancy, and both partners should stop taking leflunomide starting months before trying to conceive. Use birth control when taking this medicine, and talk to your doctor about the safety of leflunomide if you and your partner are considering pregnancy.

People who use other types of immunosuppressants may have an increased chance of developing cancer. However, studies so far have not found that leflunomide raises cancer risk.

Work With Your Doctor

Your doctor may recommend starting DMARDs soon after your PsA diagnosis. This type of treatment can help limit the amount of damage that occurs from this disease.

Finding a DMARD that works for you can be a long process. You might need to try multiple medications before you find one that controls your symptoms without leading to unmanageable side effects. You’ll likely have to wait a couple of months after trying each medication to determine whether it’s working.

If you have questions or concerns along the way, be sure to discuss them with your doctor. Together, you’ll develop the best treatment plan to manage your PsA.

Talk With Others Who Understand

On MyPsoriasisTeam, the social network for people with psoriasis and their loved ones, more than 115,000 members come together to ask questions, give advice, and share their stories with others who understand life with psoriasis.

Have you tried leflunomide for the treatment of psoriatic arthritis? Do you have questions about using DMARDs such as leflunomide? Share your experience in the comments below, or start a conversation by posting on MyPsoriasisTeam.