What does elimination half-life of a drug mean?
The definition of elimination half-life is the length of time required for the concentration of a particular substance (typically a drug) to decrease to half of its starting dose in the body.
What is half-life of a drug example?
Or, put another way, the half-life of a drug is the time it takes for it to be reduced by half. For example, the half-life of ibuprofen (the active ingredient in pain and fever relievers such as Advil and Motrin) is about two hours.
What does the term half-life refer to quizlet?
Half life definition. the average time it takes for the number of nuclei in a radioactive isotope sample to halve. the radioactivity of a sample always. decreases over time.
What do you mean by half-life?
half-life, in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay (change spontaneously into other nuclear species by emitting particles and energy), or, equivalently, the time interval required for the number of disintegrations per second of a radioactive …
What does half-life refer to?
The half-life of a drug is the time it takes for the amount of a drug’s active substance in your body to reduce by half.
Which definition describes a half-life?
1 : the time required for half of something to undergo a process: such as. a : the time required for half of the atoms of a radioactive substance to become disintegrated.
Which is the correct expression for half-life?
The time taken for half of the original population of radioactive atoms to decay is called the half-life. This relationship between half-life, the time period, t1/2, and the decay constant λ is given by t12=0.693λ t 1 2 = 0.693 λ .
What’s the meaning of half-life?
Definition of half-life 1 : the time required for half of something to undergo a process: such as. a : the time required for half of the atoms of a radioactive substance to become disintegrated.
What does half-life represent?
Half-life (symbol t1⁄2) is the time required for a quantity to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive.
What does the term half-life means?
What half-life means?
What is meant by half-life and mean life?
The mean life of a particular species of unstable nucleus is always 1.443 times longer than its half-life (time interval required for half the unstable nuclei to decay). Lead-209, for example, decays to bismuth-209 with a mean life of 4.69 hours and a half-life of 3.25 hours.
What is the definition of half-life quizlet?
What is the elimination half-life of a drug?
The elimination half-life of a drug is a pharmacokinetic parameter that is defined as the time it takes for the concentration of the drug in the plasma or the total amount in the body to be reduced by 50%. In other words, after one half-life, the concentration of the drug in the body will be half of the starting dose.
What is the symbol for the half life of a drug?
The symbol for half-life is t½. For example, if 100mg of a drug with a half-life of 60 minutes is taken, the following is estimated: 60 minutes after administration, 50mg remains 120 minutes after administration, 25mg remains
How do you calculate the elimination half-life of a compound?
The elimination half-life (t ½,elim) can be defined in the same way as was done previously for absorption and distribution by the equation. (10.79)t½,elim=ln(2)k≈0.693k. This equation can then be combined with Equation (10.78) to give the relationship between clearance (CL) and the elimination half-life as.
Is elimination half-life dependent on clearance rate?
Elimination half-life is a dependent variable, related directly to volume of distribution and inversely to clearance. Changes in drug distribution as well as in rate of clearance can alter elimination half-life.