Psoriatic arthritis (PsA) is a long-term, inflammatory disease affecting the joints and where tendons and ligaments connect to the bones. It doesn't have a cure. But a growing number of treatments can lessen your pain, stop the disease from getting worse, and help your joints move the way they’re supposed to.
DMARDs (disease-modifying antirheumatic drugs) are used to treat several inflammatory conditions. In addition to psoriatic arthritis, they may be used for other connective tissue diseases and some cancers. DMARDs can slow the progress of psoriatic arthritis and prevent permanent joint damage.
What Are the Types of DMARDs?
The three types of DMARDs are biologic, conventional, and targeted synthetic DMARDs. These all have the aim of slowing down PsA to save the joints. They do it by reducing inflammation and affecting the immune system in different ways, based on the DMARD.
Conventional DMARDs, sometimes called traditional DMARDs, include:
- Leflunomide (Arava)
- Methotrexate (Otrexup, Trexall), which is used most commonly
Biologic DMARDs target unique specific pathways in the immune system compared to conventional therapy. This class of DMARDs includes:
- Tumor necrosis factor inhibitors (TNFi), which target cytokines, proteins that are active in inflammatory arthritis. They’re the most commonly used biologic DMARD:
- Other biologics target different molecules in the immune system, including T cells and B cells:
There is only one targeted synthetic, tofacitinib (Xeljanz). It’s the newest option. The FDA approved tofacitinib in 2017 to treat PsA in people whose PsA didn’t respond well to other drugs. It’s taken with a nonbiologic DMARD (like methotrexate).
Depending on the medication used, these drugs may be given in a pill, through your veins, or as a shot just under the skin.
How Can You Figure Out Which DMARD to Use?
Your doctor will likely try the conventional option first, then give you the biologic if conventional therapy doesn't work or your PsA gets worse. Targeted synthetic DMARDs might be considered if both of those options aren’t working for you.
In some cases, depending on what your doctor recommends, you may have "double therapy." That’s when you take two types of DMARDs at the same time. For example, you may be given a biologic and methotrexate, a conventional DMARD, as a way to make the biologic work better. There is also "triple therapy," when three conventional DMARDs are given together. Research suggests this can be as effective as double therapy.
How Do DMARDs Help With Psoriatic Arthritis?
DMARDs are meant to improve your PsA, but each works differently.
- Conventional DMARDs calm down your immune system broadly, so it doesn't attack healthy tissues.
- Biologic DMARDs target specific cells or inflammatory pathways instead of the entire immune system. They can work on cytokines, or on T cells or B cells.
- Targeted synthetic DMARDs target specific proteins in your immune system, too. This drug is available as a daily oral tablet rather than an injection. That may be a better option for people who want more convenience.
All three DMARDs help with psoriatic arthritis by changing the activity of the immune response in a way that lowers inflammation. Without controlling or blocking inflammation, you could have long-term, permanent joint tissue damage and loss.
It's possible that a single DMARD may control your psoriatic arthritis. But it's more common for two or more medications to be used together to ease your symptoms and protect joint health.
This might mean combining DMARDs or using a DMARD with other medications like corticosteroids or nonsteroidal anti-inflammatory drugs (NSAIDs). Because DMARDs can sometimes take weeks or even months to work, these other medications are often used to take care of immediate symptoms like pain and joint swelling. But the steroids can only be taken for a short time because they come with serious side effects.
What Are the Side Effects of DMARDs?
All DMARDs can cause mild side effects including nausea and diarrhea, especially when you first start taking them. You might also have headaches and loss of appetite.
The risk of serious infections or cancer is increased if you take two or more biologic DMARDs together, or a biologic DMARD with a nonbiologic DMARD.
Because these medications control inflammation by slowing down your immune system, you can have a higher risk of infection. It’s very rare, but they could also give you a greater risk for cancers of immune cells, like lymphoma.
The targeted synthetic DMARD can put you at greater risk for blood clots, heart attack, stroke, or even death if you’re 50 or older and have heart disease risk factors already.
What If the DMARD Doesn't Work?
If the conventional DMARD you're trying first doesn't work to reduce inflammation, you have options. Your doctor might try a combination of multiple DMARDs, using a conventional with a biologic, taking DMARDs with other medications, or simply switching from one DMARD brand to another.