Psoriasis Medication Systemic Therapy
The term ‘systemic therapy’ is sometimes confusing to patients. It simple means that substances will be used that can have an effect throughout the body. In other words it is not isolated to a specific area. Psoriasis systemic therapy involves the use of drugs that are taken through the mouth (oral medication) or drugs that are injected into the body (parenteral medication).
Mild psoriasis and the early stages of psoriasis can be treated with psoriasis creams and lotions. This treatment is topical meaning that it is only applied on the skin at the area where the problem exists. Once the psoriasis worsens and the topical treatment is not giving the desired effect, systemic therapy is considered. In most cases this involves the use of oral medication in the form of tablets or capsules.
Psoriasis Medication Indications
When should psoriasis drugs be used?
The time when psoriasis medication should be started depends on several factors. Usually if more than 20% of the skin on the body is affected and the psoriasis is of a severe type then drugs are started. It also depends on the preference of the doctor and the reports of the patient in dealing with symptoms like itching of the skin. Psoriasis that is persisting for a long period of time without any sign of improvement with the use of creams and lotions may also require the use of medication at the same time.
Types of Psoriasis Medication
There are many types of drugs which can decrease inflammation of the skin, slow down skin growth and suppress the immune system. These effects are helpful because psoriasis is a skin disease where the skin is inflamed, the cells grow too fast and the immune system is abnormally active.
The three main oral medication used in psoriasis treatment is :
The main types of injected medication are known as biological agents and includes :
- Tumor necrosis factor (TNF) blockers
- Drugs that inhibit T-lymphocytes (type of immune cell)
- Drugs that inhibit interleukins (type of immune chemical)
Psoriasis Oral Medication
Most oral medication for psoriasis suppresses the immune system. By making the immune system less active, the disease eases but the body also becomes prone to infections. Therefore these drugs are either used in low doses or for short periods of time. Some drugs can also slow down skin growth which is faster than normal in psoriasis.
Acitretin for Psoriasis
Acitretin is a synthetic substance that resembles vitamin A. It is known as a vitamin A analogue. This substance can suppress the immune system which is helpful in psoriasis since it is the immune system that is irritating the skin. This property of acitretin is known as immune suppression. It can also reduce the speed at which skin cells grow and this function is known as antiproliferation. In psoriasis the skin cells proliferate very fast which causes the skin to become thickened. Therefore acitretion is known as an immunosuppressant and antiproliferative drug. It should only be used for the severe types of psoriasis like pustular psoriasis and for psoriasis that is resistant to other treatment.
Acitretin can cause the skin to become dry and scaly which worsens the symptoms of psoriasis. It may also cause :
- Painful joints
- Muscle aches
- Hair loss (scalp and body)
- High cholesterol levels
- Liver damage
- Fetal defects in pregnant women
Cyclosporine for Psoriasis
Cyclosporine suppresses the immune system (immunosuppressant). It is used treat severe psoriasis particularly when it is affecting large parts of the skin on the body. Cyclosporine works rapidly and the benefits are therefore seen quickly. However, stopping the drug usually causes the symptoms to return soon thereafter. Although cyclosporine can be used for long periods of time it should not be used for longer than 2 to 3 years.
- Kidney damage
- High blood cholesterol
- High blood pressure
Methotrexate for Psoriasis
Methotrexate is a drug that blocks the the way the body processes vitamin B9 (folic acid). It is an immunosuppressant meaning that it suppresses the activity of the immune system. It is very effective for conditions like psoriatic arthritis where psoriasis occurs with arthritis but can also be used for psoriasis on its own. Methotrexate is very effective and can be safely used in low doses for many years. However, not every psoriasis patient may experience the benefits.
The main side effect is liver damage. It is therefore essential that a person using methotrexate is monitored on a regular basis.
Psoriasis Injectable Drugs
Another class of drug that may be used in psoriasis treatment is biological agents. These drugs have the same effect as certain natural substances in the body. It is available as injectable drugs and can be used for a number of different diseases apart from psoriasis. Biological agents block certain immune chemicals that can excite the immune system and make it active. It is also known as immunomodulators because of the way it alters immune activity. However, it can also upset the normal protective ability of the immune system. This means a person is prone to infections and sometimes even cancers which are naturally fought off by the immune system.
TNF blockers for psoriasis
Tumor necrosis factor (TNF) blockers (etanercept, infliximab and adalimumab) is useful in treating both psoriasis and arthritis. As the name suggests this drug attaches to a naturally occurring chemical known as tumor necrosis factor (TNF) and block it from exciting the immune system. However, over months and years these drugs become less effective. These drugs should not be used by a person with heart failure, nerve disorders and with low blood cells, whether red blood cells or white blood cells.
Drugs to inhibit T-lymphocytes activation
T-lymphocytes are a type of immune cell. When activated, these immune cells then attacks certain invaders like viruses but in psoriasis it can also cause inflammation of the skin. Certain types of drugs prevent the activation of these T-lymphcytes. Once such drug is alefacept which can be injected into the vein or muscles. It is used specifically for the chronic plaque type of psoriasis. Alefacept is not approved for use in all countries because of the risk of infections, allergies and cancer when using it.
Drugs to inhibit interleukins
Another group of immune chemicals is known as interleukins. It can activate the immune system. Drugs like ustekinumab and Efalizumab block specific interleukins. By doing so the immune system cannot be excited or activated. These drugs are used in moderate to severe plaque psoriasis. Efalizumab has been discontinued from the US market because of serious brain diseases (encephalopathy) associated with it.
Article reviewed by Dr. Greg. Last updated on May 7, 2012