Expert: JM Starkman, MD - 9/11/2009

Question
Dear Dr. Starkman,
> In 2007, I had a "disinhibition episode" 4 days after outpatient surgery.  It points strongly to the Versed as the cause.  
> What is the usual time that such drugs stay in the body in effective concentrations to cause side effects?
> BTW, I am a senior citizen, take no RX- or other drugs.  Have never been able to tolerate drugs.  I avoid any drug unless it is a matter of life or death, or in case of a serious illness.  
Thank you.     Phillip

Answer
The time drugs remain in one's body is described as the "half-life" of that drug and it is an indicator of the approximate time frame a drug's SERUM concentration decreases to one half its beginning concentration in SERUM.  That number for midazolam (Versed) varies from under 2 to over 6 hours--there are many individual variables.  The time that the concentration of a drug drops to very low or irrelevant concentrations becomes a statistical matter, and four half-lives would therefore leave very little detectable drug in the SERUM.  Obviously, the whole subject, formally known as pharmacokinetics, gets pretty complicated pretty quick---search some of these terms I've used here to get a more thorough understanding of your question.  And remember, the serum concentration of a drug is probably different than the concentration in other tissues e.g., brain, liver, etc.