Systemic treatments are not applied directly on the skin, they are administered in other ways (tablets, injections, etc.). These types of treatments affect the entire body and therefore used only for the hardest forms of psoriasis.
There are many different systemic medications including:
The biological agents are made from living sources to work in the immune system. Biologic therapies harness the proteins and cells involved in psoriasis.
Biologic therapies have been available for other diseases for a longer time and are now beginning to be approved for the treatment of psoriasis.
Cyclosporine is a drug that slows skin growth by preventing some of the activity of the immune system. This drug is immunosuppressive and antifungal. It is used to prevent the rejection of transplanted organs and has been approved for use in psoriasis but is generally reserved for severe cases where other therapies have failed. When used for psoriasis, the dose is much less than for organ transplant rejection. More than 90% of patients experience clearing with cyclosporine.
Side effects can be serious, and careful patient selection and monitoring must be undertaken when cyclosporine is prescribed. Serious side effects include renal impairment and hypertension. Other side effects include hirsutism (excessive hair growth) and gum hyperplasia. Males may experience enlarged breasts. Another important issue is that when treatment is stopped the psoriasis frequently returns.
MTX is a drug that slows down the rapid growth of skin cells and suppresses the immune system. This cytotoxic drug was originally used to treat cancer and was approved for use in psoriasis in the 1970s. It is effective, but toxic to cells and other organ systems. MTX can be taken orally or given as an injection.
It should not be taken by people who regularly consume alcohol, those who have abnormal liver or kidney function, immunodeficiencies or active infection.
Kidney, liver and bone marrow function must be monitored closely, including liver biopsy. MTX can cause birth defects and abortion and should not be used by pregnant woman. Other side effects include anemia, nausea, fatigue, loss of appetite, phototoxicity, diarrhea, mouth ulcers, headache, fever and chills.
Derived from vitamin A, these drugs regulate how skin cells grow and are shed from the surface of the skin. These drugs are related to Vitamin A and work by normalising the growth of keratinocytes. They may be useful in treating severe forms of psoriasis that have not responded to other therapies.
Side effects include dry skin, dryness of the eyes and nasal passages, chapped lips, sun sensitivity, hair thinning and bone spurs of the long bones or spine.
Retinoids can not be used in pregnant women or by women who try to conceive a baby bacause of serious fetal defects. Pregnancy must be avoided for up to 3 years after stopping taking the drug.