It is believed that Interferon beta based drugs achieve their beneficial effect on MS progression via their anti-inflammatory properties. Studies have also determined that Interferon beta improves the integrity of the blood-brain barrier (BBB), which generally breaks down in MS patients, allowing increasing amounts of undesirable substances to reach the brain. This strengthening of the BBB may be a contributing factor to Interferon-Beta's beneficial effects. These studies were carried out in vitro (outside a living organism; a "petri dish" experiment), so it does not necessarily mean it works the same in people.
Nonetheless, Interferons have side effects. The two main ones are flu-like symptoms, and injection-site reactions. The flu-like symptoms tend to happen immediately after the injection, and last for about half a day. In many patients, these symptoms diminish over time, but some patients continue to experience them over the long term. One can mitigate these symptoms by using a dose that is injected less frequently, and by taking the medication before bedtime. The injection-site reactions can be mitigated by rotating injection sites, or by using one of the medications that requires less frequent injections. Side effects are often onerous enough that many patients ultimately discontinue taking Interferons (or Copaxone®, one of the other disease-modifying therapies requiring daily or weekly injections).
The most commonly reported side effects are injection site disorders, flu-like symptoms, elevation of liver enzymes and blood cell abnormalities. Patients with depression, seizure disorders, or liver problems, should discuss treatment with Rebif with their doctors.
While these drugs improve certain diagnostic test results, many patients report no perceived improvement, along with serious side-effects that substantially reduce quality of life. It is important to recognize that these drugs are intended to treat symptoms and possibly delay disease progression, but do not provide a cure to multiple sclerosis. Furthermore, tolerance develops over time in some patients, due to the development of "neutralizing antibodies," which reduces the effectiveness of these drugs, while side effects may persist even after discontinuation.
