Cyclosporin A has been used for the past 25 years to avoid organ rejections in patients receiving transplants. It has been shown to work well for skin psoriasis, and also helps the arthritis. Although there are no studies comparing cyclosporin A to placebo, it compares favorably to methotrexate and appears superior to sulfasalazine. It is not as well tolerated as methotrexate.

Mechanism of action

Cyclosporin A interferes with T cell function and thus helps to suppress the inflammation of psoriasis and psoriatic arthritis.

Mode of administration

Cyclosporin A is given orally at doses of 3-5 mg/kg per day. It is available in 25, 50 and 100 mg tablets. Most people require between 100 and 300 mg per day. It takes 3-4 months to notice an effect with cyclosporin A.

Side effects

Cyclosporin A has several side effects. It may suppress the bone marrow, cause high blood pressure and kidney problems, which make its use limited. People taking cyclosporin A should have their blood pressure checked at two week intervals when starting on this medication. The frequency may be reduced to once a month once a stable dose has been achieved. Blood tests should also be done at monthly intervals, including hematology, liver and kidney function tests. If there are abnormalities in either blood pressure or laboratory tests the dose of cyclosporin A is reduced, or the drug may be discontinued altogether.