The length of time it takes for the body to metabolize or eliminate from the body 50 percent of the amount of a DRUG a person takes or receives. Drug half-life is an important factor in determining appropriate DOSAGE and for treating OVERDOSE. Drug half-life also helps the doctor know when to expect to begin to see the effects of the drug. The calculation of drug half-life is logarithmic.
Drug informational literature, packaged with prescription drugs, provides general information about the drug’s half-life that is generally adequate for most clinical circumstances. A doctor may conduct BLOOD tests to measure the levels of a drug in an individual’s blood circulation over a period of time as a means of indirectly assessing half-life, though this is seldom therapeutically necessary.