Oral immunosuppressive drugs.

The last few decades have witnessed remarkable achievements in the development of immunosuppressive drugs, made possible by significant advances in molecular immunology and improved understanding of the mechanisms by which cells communicate. The identification of the relevant cells involved in a pathological process is the key to understanding effective immunosuppressive strategies. For example, understanding the role of the activated CD4+ T cell in cellular rejection of grafts has revolutionised transplant therapies. Many immunosuppressive drugs are used for unlicensed indications. It is difficult to achieve a balance between adequate control of the disease process and overimmunosuppression leading to infections and malignancy. This review examines the commoner agents in use, highlighting which part of the immune system they modify, their most important side effects and monitoring strategies (Tables 1–3). The adaptive immune system of both T and B cells relies on the non-specific uptake of antigen by antigen presenting cells (APCs) (eg monocytes and dendritic cells). Specific inhibitors of this process are not commercially available. Drugs such as minocycline4 and chloroquine4,5 can inhibit the processing of antigens by APCs, which is the reason for their anti-inflammatory effect.