Psoriatic arthritis affects about 30% of people with psoriasis. Those with psoriatic arthritis experience tenderness, redness and pain in joints such as the hip, knee, wrist and fingers. The pain can range from irritating to excruciating. For less than 5% of individuals with psoriatic arthritis, the disease can damage bones in the fingers and hands. For this group, psoriatic arthritis can mean permanent deformities and intense pain.
Psoriatic arthritis generally occurs among those with poorly treated psoriasis symptoms. So, the first step in treating psoriatic arthritis is to catch it before it starts. Once the condition has been diagnosed, however, new treatment methods are promising more symptom-free days and a greater chance of halting the progression of the disease. But these medications are not without the potential for serious side effects, and you must talk with your physician about the benefits and risks of taking them.
A Variety of Treatments
Although none of the many new medications are a cure for the disease, most offer symptom relief for a majority of patients. These drugs are in a class of medications called tumor necrosis factor (TNF)-alpha inhibitors; however, they are more commonly referred to as biologics. TNF-alpha is a protein released into the body during an immune response. It works like the general of the white blood cells, sending them off to fight infection. The cluster of white blood cells creates a pocket of inflammation.
In a normal immune response, the TNF-alpha dissipates after dealing with the infection. But in those with autoimmune disorders, such as psoriasis and psoriatic arthritis, TNF-alpha remains in the bloodstream at higher than normal levels. This can then cause inflammation, in places like finger and hip joints, where there is no infection. The buildup of inflammation results in pain and damage to tissues, such as cartilage and bone.
TNF-alpha inhibitors work by limiting the impact of TNF-alpha on the body. They reduce the amount of inflammation and resulting pain by stopping it before it starts. Examples of these medications include Remicade (infliximab), Humira (adalimumab) and Enbrel (etanercept).
In addition to these medications, Golimumab, a new TNF-alpha inhibitor, may hold additional promise for those with psoriatic arthritis. Centocor Inc. and Schering-Plough Corp., the companies that developed Golimumab, say their clinical trials indicate that more than half of patients experience a 20% improvement in symptoms after 14 weeks. The drug, which has not yet been submitted for FDA approval, has not yet been evaluated by an independent study.
All TNF-alpha treatments are delivered either intravenously or by injection. Because they suppress the immune system, the risk of infection while using these drugs increases. As a precaution, a doctor will give a patient a tuberculosis test beforehand to determine if the individual has been exposed. Patients should also avoid exposure to any infectious disease while using these drugs.
According to the National Institutes of Health, Humira can cause nausea, back pain, headache, stomach discomfort and redness or swelling at the injection side. More serious, but rare, side effects include muscle weakness, itchiness, fever, shortness of breath, vision problems and swelling of the feet, hands or face.
Remicade has a higher risk of allergic reaction because it is injected directly into the bloodstream through an IV. Reactions, such as itching and swelling of the face, feet or hands, typically appear within 2 hours of treatment. In most cases, a nurse will observe those receiving treatment for about 2 hours.
Those taking Enbrel are also at risk for side effects. These include redness at the injection site, sneezing, nausea or vomiting, cough or sore throat and runny nose. More serious side effects include seizures, fever, breathing difficulties and hives.
An increased risk of infection is also among the serious potential side effects of these drugs. These serious side effects are rare, but should be reported to a physician immediately if they occur.
Possible Cancer Risk
There is some evidence to suggest that biologics may increase a patient's risk of lymphoma, melanoma and non-melanoma skin cancer. However, the data is inconclusive. The increased risk that has been observed in some studies is slight, but worth discussing with a physician. Those with a history of these cancers should especially have a conversation with a doctor about these potential risks prior to starting a biologic therapy.
In an analysis, published in 2006 in the Journal of the American Medical Association, a group of 3,493 patients taking Humira and Remicade reported 29 malignant cancer diagnoses within 56 weeks of their trial period. The patients took various doses of the biologics to treat rheumatoid arthritis. In a control group using a placebo, three malignancies were reported. The study also found that those taking higher doses were more likely to have a malignant diagnosis.
Recently, the FDA made safety changes to the packaging of Remicade, Humira and Enbrel. The packages now include a boxed warning with the strongest warning label available.
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