If a drug has a half-life of, say, 16 hours, how does the concentration in the body reach zero at some point?

Question

If a drug has a half-life of, say, 16 hours, how does the concentration in the body reach zero at some point?

In: 2

Answer 1

The basic rule of thumb that gets used is that you’re not considered to have a meaningful amount of drug in your blood after 4-5 half-lives (which will eliminate 95%+ of what’s in your system).

5% of the original concentration of a drug is usually not going to have much of a clinical effect, so in most cases this is a safe estimate.