AboutBarbara Judge Expertise Outpatient pharmacy and general health. I have recently completed a Pharmceutical Care Certificate Program offered by Purdue University (Spring 1999 completion). I have personal experience dealing with terminally ill persons and their needs, as well as their families` needs. I graduated in 1984 from Pharmacy School and have been a Licensed Pharmacist since then. I have 18 years retail pharmacy experience. Prior to my pharmacy training I have 3 years hospital experience as a Nurse`s Aide.
Expert: Barbara Judge Date: 5/12/2007 Subject: Medication Half Life
Question Hello, Ms. Judge!
Two questions:
1. What is the half-life of a medication?
2. Is there a "general rule" for determining how long a medication will stay in your system (I know in the old days, we used to hear you needed to detox for three full days to eliminate most narcotics before you could expect to have a clear drug screen -- and that was if you were NOT a chronic user)
I need to understand this before I can get to the question I really want to ask.
Thank you.
Answer 1. The half-life of a medication is the time it takes for your body to metabolize and excrete a drug so that half of the drug is removed from your body.
2. As a general rule you are considered fully clean in blood and urine after 5 half lives. Keep in mind that the half of every drug varies greatly. Half life can also vary from patient to patient if the patient suffers from altered kidney or liver function.
If you want complete information on drug screening, the most complete and accurate source of information I have found is www.erowid.org. This website lists commonly performed tests, time frames for one time users, long term users, and drugs or other products that cause false positive tests. It is the best source I have found. Any question you ask me I will most likely reference that website if I don't know the answer.
