I took .5 mg of xanax (alprazolam) for the first time in probably 6 to 9 months. One time only every few months but i wanted to know how long it would be in my system consider i have to take a drug test in about 2 weeks. I am about 5'4 130 pounds. Please help with any information!!
The plasma elimination half-life of Xanax is reported to be 11.2 hours. The full range is from 6.3 to 26.9 hours in healthy adults. This is the time it takes for your body to reduce plasma drug levels by half.
For a drug to be totally eliminated from your system it takes around 5.5 times the half life. If we take the maximum time of 26.9 hours times 5.5, it will be in your system for approximately 148 hours i.e. 6 days, after your final dose.
However other factors to consider include:
1. How much and how often you have taken the drug.
2. Your metabolic rate – a slower metabolism will increase the time a drug remains in your system.
3. Your age and health – older age and poor health will generally increase the time the drug stays in your system.
4. Body mass – generally the bigger you are the longer a drug will remain in your system.
There is no exact number for the time it takes for a drug to be completely eliminated from the body. Drug metabolism is affected by many variables - age, smoking status, other drugs, liver function, kidney function etc.
Most drugs have what is called an "elimination half life" which is the time it takes for the drug to reach half of its pharmacologic activity. For Xanax this is about 11.2 hours.
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