Psoriasis is a commonly occurring chronic skin disease in which the life cycle of skin cells greatly accelerates causing dead cells to accumulate on the epidermis, according to MayoClinic.com. This accumulation of dead cells leads to thick scales and dry red areas that may be painful. Psoriasis develops when cells in the immune system called T lymphocytes mistakenly attack healthy skin cells, leading to subsequent immune responses. Biologics, also called immunomodulators, treat psoriasis by blocking the action of T lymphocytes or certain immune system proteins.
Alefacept
Alefacept, sold under the brand name Amevive, is an injectable biologic that doctors prescribe for the treatment of moderate to severe psoriasis, explains Drugs.com. It works by suppressing the activity of T lymphocytes in the immune system and diminishing the rate at which skin cells grow and divide. A doctor or other health care professional administers alefacept via an intravenous injection once a week. Patients should be aware that alefacept may cause dizziness and therefore they should not drive or do anything that requires alertness until they know how they react to it. Other common side effects may include cough, muscle aches, nausea, pain or swelling at the site of injection and sore throat.
Ustekinumab
According to the National Psoriasis Foundation, ustekinumab, manufactured as Stelara, is a biologic drug that can treat psoriasis by blocking the action of the cytokines interleukin 12 and interleukin 23. Cytokines are proteins produced by cells of the immune system. They interact with receptors on immune system cells to regulate the body's response to infection. Interleukins 12 and 23 mediate an inflammatory response, and doctors believe that they promote the aggregation of psoriasis-causing T lymphocytes in the epidermis. Patients receive ustekinumab via a subcutaneous injection given by a health care professional.
Infliximab
Infliximab, sold under the brand name Remicade, is a monoclonal antibody inhibitor of tumor necrosis factor-alpha, an immune system protein that mediates inflammatory responses. Patients with psoriasis have too much tumor necrosis factor-alpha in the skin and this leads to inflammation and a rapid growth of skin cells. By blocking the ability of tumor necrosis factor-alpha to bind to immune cell receptors, infliximab interrupts the inflammatory cycle of psoriasis and affords symptomatic relief to patients. A doctor or nurse administers infliximab as an intravenous infusion over a two-hour period, and patients get the infusion once every two to eight weeks. It is important for patients to know that infliximab may make them more susceptible to serious bacterial, viral or fungal infections that can become systemic. Common side effects may include stomach pain, nausea, heartburn, headache, runny nose, back pain and white patches in the mouth.
