What does the term "wash out period" mean?

Question:
What does the term "wash out period" mean?

My research indicates that it could mean lots of things like:

• Plasmaphoresis (cleaning the blood out entirely via machine

• Stopping the Tysabri and any other medication for 3 to 6 months and then initiating another medication

• Having IV infusions of prednisone every week for each week that one is off of any of the other medications
  

Answer:
To "wash out” simply means to remove a substance (usually a drug) from the body either naturally or through an accelerated process. Many drugs hang around for quite some time after your last dose. For instance, Tysabri takes 3 months to “wash out” naturally and Aubagio can take many months. We can sped up the elimination of Tysabri by performing plasmaphoresis and we can sped up the elimination of Aubagio by giving an individual cholestyramine. However, the biological effects of a drug can persist long after the drug is eliminated from the body. Lemtrada is a great example. The effects of this drug persist for years after your infusions are complete even though no Lemtrada is detectable in your body 60 days after your infusions (elimination half life of 2 weeks).

Hope this answers your question.

Revere (Rip) Kinkel MD
Director of the Multiple Sclerosis Program
Professor of Clinical Neurosciences
University of California San Diego