Disease-modifying anti-rheumatic drugs (DMARDs)

DMARDs (disease-modifying anti-rheumatic drugs) are used to reduce inflammation and prevent psoriatic arthritis (PsA) from getting worse. This family of medications works by helping to block the immune system's attack on the joints and nearby tissues.

DMARDs used in Canada for PsA include methotrexate and gold salts.

Methotrexate (Methotrexate®, generics)

• What does it do? The way methotrexate works in psoriatic arthritis symptoms is not exactly clear, but it is believe to reduce inflammation and suppress the immune system.
• How do I use it? Methotrexate usually taken orally (by mouth) once weekly.

Gold salts or sodium aurothiomalate (Myochrysine®)

• What does it do? Gold salt is believed to work by interrupting processes in the body that cause inflammation, thereby reducing inflammation associated with psoriatic arthritis.
• How do I use it? Gold salt is injected into a muscle (intramuscular (IM) injection) once weekly by a health care provider until the full benefits are seen, then every 2 to 4 weeks.

The choice of which DMARD is best for a particular individual depends on a number of factors, including the severity of the disease and the balance of benefits versus risk for each treatment. In some cases, different DMARDs may be tried to see which one works best with the least amount of side effects.

Pregnancy should be avoided if either partner is using methotrexate, as this medication can cause birth defects. Pregnancy should also be avoided for a minimum of 3 months after finishing treatment with methotrexate. This medication can also lead to an increase in liver enzymes, which is a concern if the situation is persistent. Your doctor will test the function of your liver regularly while you are on methotrexate.

Common side effects of DMARDs include mouth sores, nausea, vomiting, diarrhea, and skin rash. Rare but serious side effects of DMARDs include allergic reactions; damage to the kidneys, liver, or bone marrow; and a reduced ability to fight off infections.