Chemotherapy Drugs
The most commonly used DMARD is methotrexate. Taken by mouth or injection, it is an immunosuppressive drug approved by the Food and Drug Administration (FDA) for the treatment of psoriasis, but it is also used widely and successfully for treating psoriatic arthritis. Methotrexate has proven effective at relieving the symptoms associated with psoriatic arthritis, and studies suggest it may help prevent joint destruction as well. It works by binding to an enzyme that is involved in the rapid growth of cells. Sometimes it is given in combination with other drugs to alleviate the signs and symptoms of psoriatic arthritis.
Methotexate is usually well tolerated in low doses. However, a number of side effects are associated with it, including the long term potential for liver damage. Regular blood tests are also needed to ensure that the body is tolerating the drug properly and to see if there are any negative effects on the bone marrow or the blood. Methotrexate can lower white blood cell counts, which can make a person more prone to infection.
Antimalaria Medications
Antimalaria drugs, such as hydroxychloroquine (Plaquenil®), are also effective at relieving pain, reducing joint inflammation and decreasing damage to the joints, skin and other organs in the body. Generally, it takes from 8 to 12 weeks for the body to respond.