Zyban is a non-nicotine aid to smoking cessation. It is chemically unrelated to nicotine or other agents used in the treatment of nicotine addiction. It is developed as an antidepressant and is chemically unrelated to tricyclic, tetracyclic, selective serotonin re-uptake inhibitor, or other known antidepressant agents. It decreases cravings and withdrawal symptoms of smoking.
Common side effects of Zyban include dry mouth and difficulty sleeping. Other less common side effects dizziness, difficulty concentrating, upset stomach, anxiety, constipation, tremors, or skin rashes. There is also a small risk of having seizures, serious or unusual changes in mood, an liver damage.
The use of Zyban has led to lawsuits involving side effects such as birth defects, suicidal behavior, and psychiatric problems. The drug also has a black box warning stating that it may cause changes in behavior, including depressed mood, hostility and suicidal thoughts.
Tysabri, or natalizumab, is a laboratory produced monoclonal antibody. Antibodies are made to target and destroy potentially damaging immune cells from the bloodstream, across the blood-brain barrier into the brain and spinal cord. It is used to treat relapsing forms of multiple sclerosis and moderate to severe forms of Crohn’s disease in adults. It is usually used as a last resort when other medications have proven ineffective.
Tysabri may cause a severe viral infection of the brain that can lead to disability or death. The risk is increased in those who are receiving certain medicines or have a weak immune system. Symptoms of severe side effects can include changes in the mental state, problems with speech or walking, or decreased vision. There have been cases of patients developing PML, a usually fatal brain sisorder, after receiving multiple doses of natalizumab, the active ingredient in Tysabri.
Tysabri has been tied to serious liver damage and PML, and may also link to the skin cancer melanoma. It was first pulled from the market in 2005 after being linked to PML, but the FDA decided soon afterwards that its benefits in treating MS outweighed its risks. In 2008 it also won approval to treat Crohn’s disease. There have been lawsuits on the rise for Tysabri’s role in causing both of these fatal disorders. Attorneys contend that it is a defective drug that is too dangerous to be used to treat any condition.