Tysabri and Arthritis Side Effects
Rheumatoid arthritis and related inflammatory arthritic diseases belong to the class of autoimmune illnesses. Just as an allergy causes the body to react violently to otherwise harmless substances like pollen, in autoimmune illnesses the body attacks its own normal tissues as if they were foreign bodies. One of the effects of the immune system being activated is inflammation, and when this exists in the joints it produces arthritis. The chemicals produced attack the cartilage and other connective tissues and damage the joints leading to disability caused by pain and loss of mobility.
At one time, the only treatment for arthritis was not aimed at reducing the disease but merely to try to relieve the pain. Deformity and damage continued to progress. It was fortunate that some of the earliest pain relievers like willow bark tea and later aspirin were also anti-inflammatory medicines that really treated the problem. Today there are many classes of medications to treat inflammatory arthritis and related conditions such as Sjogren’s syndrome and systemic lupus.
The main classes of drugs are the non-steroidal anti-inflammatory drugs, or NSAIDs, steroids, analgesics, disease modifying anti-rheumatic drugs or DMARDs, and the newest class, the biological modifiers including Tysabri. This drug was originally used to treat Crohn’s disease of the intestines and some forms of multiple sclerosis. It works to directly alter the function of the immune system to reduce the attack on normal tissue. Tysabri is the brand name for the drug natalizumab.
Studies on the use of Tysabri in the last few years have shown that it can be of value in treating rheumatoid arthritis just as occurs with the use of other biologic modifiers like Enbrel and Orencia. But the drug has had a troubled past. It was approved in 2004 but withdrawn in 2005 when two patients developed a severe brain disease called PML. Further studies were done on both Crohn’s patients and rheumatoid arthritis patients however and no more cases of PML were seen in either set of patients so the FDA allowed use again in 2006 with restrictions.
Natalizumab or Tysabri has many of the same side effects as other biologic modifiers. It is in the subclass of TNF blockers. In addition to the very rare but potentially lethal PML, this drug can also damage the liver which means extra caution in its use. Like all drugs, allergic reactions are possible. The most common side effects are rash, headache, fatigue, urinary, lung and vaginal infections, depression, stomach ache, diarrhea and ironically, joint pain.
Tysabri is not recommended for use in pregnancy or during breast feeding and should not be taken by those who already have a compromised immune system. The use of Tysabri is pretty much limited to those patients who have not been helped by other drugs or who could not tolerate them. Only a physician can decide whether the benefits outweigh the risks.
This medication must be given by IV infusion,
so treatment requires visits to an infusion center or a visit from a
home IV therapy nurse. Some patients prefer not to have IV’s but
when this medication works can adjust to this small inconvenience
every few weeks.
Resources:
General information about Tysabri:
www.rxlist.com/cgi/generic/tysabri_ad.htm
Report on the safety stories:
findarticles.com/p/articles/mi_m0850/is_/ai_n17093759
Articles about the status and use of Tysabri:
Manufacturer’s information about side effects and precautions