There are two factors that affect the elimination half-life of a drug, which include
its clearance and volume of distribution
. The clearance of the drug (CL) refers to the rate at which the body eliminates the drug from the body.
What is the correct term for the length of time for a drug concentration to decrease by half quizlet?
Half-life (t1/2)
refers to the time required for plasma concentration of a drug to decrease by 50%.
What can affect the half-life of a drug?
There are two factors that affect the elimination half-life of a drug, which include
its clearance and volume of distribution
. The clearance of the drug (CL) refers to the rate at which the body eliminates the drug from the body.
What does half-life of a drug mean?
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
. This depends on how the body processes and gets rid of the drug. It can vary from a few hours to a few days, or sometimes weeks.
Does half-life affect drug absorption?
Half-lives are commonly used in pharmacokinetics to describe
drug absorption and elimination
. The elimination half-life also determines how quickly a drug accumulates.
Which drug has the longest half-life?
However, there are numerous other drugs with very long half-life, examples are
mefloquine 14–41 days
(25), amiodarone 21–78 days (26), and oritavancin 393 h (27). Furthermore, what can be called “long half-life” is always relative to the length of the sampling period.
How do you calculate half-life of a drug?
The half-life (t
1 / 2
) is the time it takes for the plasma concentration of a drug or the amount of drug in the body to be reduced by 50%. The half-life of a drug can be determined using the following equation:
t
1 / 2
= (0.7 x V
d
) / Cl
, where Vd is volume of distribution and Cl is clearance.
Which drug should not be taken with milk?
Dairy products such as milk, yogurt, and cheese can delay or prevent the absorption of antibiotics such as
tetracyclines and ciprofloxacin (Cipro)
. This occurs because the calcium in such foods binds to the antibiotics in the stomach and upper small intestine to form an insoluble compound.
Which drugs would be affected by the first pass effect?
Notable drugs that experience a significant first-pass effect are
imipramine, morphine, propranolol, buprenorphine, diazepam, midazolam, pethidine
, tetrahydrocannabinol (THC), ethanol (drinking alcohol), cimetidine, lidocaine, chlorpromazine, and nitroglycerin (NTG).
How would the nurse best describe the half life of a drug?
The half-life of a drug is
the time taken for the plasma concentration of a drug to reduce to half its original value
. Half-life is used to estimate how long it takes for a drug to be removed from your body. For example: The half-life of Ambien is about 2 hours.
Why is half-life of a drug important?
A drug’s half-life is an important factor
when it’s time to stop taking it
. Both the strength and duration of the medication will be considered, as will its half-life. This is important because you risk unpleasant withdrawal symptoms if you quit cold turkey.
How do you explain 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 …
How does half-life affect dosing?
Effects of varying the dose interval
A dosing interval of about a half-life is appropriate for drugs with half-lives of approximately
8-24 hours allowing dosing once, twice or three times daily
. It is usually not practicable to administer drugs with shorter half-lives more frequently.
What is the difference between terminal half life and elimination half life?
Following i.v. administration, the terminal half-life is the time required
for plasma/blood concentration to decrease by 50% after pseudo-equilibrium of distribution has been
reached; then, terminal half-life is computed when the decrease in drug plasma concentration is due only to drug elimination, and the term ‘ …
What is the most important characteristic of a drug to be absorbed after oral administration?
When a drug is taken orally, it must be
able to survive the low pH and presence of potentially degrading enzymes in the gastrointestinal tract
before it can be absorbed into the bloodstream.
Does a shorter half-life mean more radioactive?
In general there is an inverse relation between the half-life and the intensity of radioactivity of an isotope. Isotopes with a long half-life decay very slowly, and so produce fewer radioactive decays per second; their intensity is less. Istopes with
shorter half-lives are more intense
.
