Pharmacology 2 Flashcards
What does context-sensitive half-time (CSHT) represent?
The time taken for the plasma concentration of a drug to decrease by 50% after a continuous infusion.
How is context-sensitive half-time (CSHT) different from elimination half-life?
CSHT takes into account the changing pharmacokinetics of a drug during continuous infusion, while elimination half-life is constant and does not change with infusion duration.
What factors influence context-sensitive half-time (CSHT) of a drug?
Factors like drug clearance, volume of distribution, and rate of infusion can influence CSHT of a drug.
How does a longer context-sensitive half-time (CSHT) affect drug accumulation during continuous infusion?
A longer CSHT indicates slower clearance of the drug, leading to drug accumulation during continuous infusion.
True or False: The context-sensitive half-time (CSHT) of a drug remains constant regardless of the duration of infusion.
False
What is the formula to calculate context-sensitive half-time (CSHT) after a continuous infusion?
CSHT = 0.693 x Vd / CL
How can context-sensitive half-time (CSHT) be shortened for a drug during continuous infusion?
Shortening the infusion duration or increasing drug clearance can shorten CSHT for a drug.
In pharmacokinetics, what does volume of distribution (Vd) represent?
The theoretical volume in which a drug is uniformly distributed at the same concentration as in plasma.
What does drug clearance (CL) represent in pharmacokinetics?
The volume of plasma from which the drug is completely removed per unit time.
How does a higher drug clearance (CL) affect context-sensitive half-time (CSHT) of a drug?
A higher drug clearance leads to a shorter CSHT as the drug is eliminated more rapidly from the body.
Fill in the blank: Context-sensitive half-time (CSHT) is a better indicator of ___________ of a drug during continuous infusion than elimination half-life.
accumulation
What is the relationship between context-sensitive half-time (CSHT) and drug accumulation during continuous infusion?
A longer CSHT results in greater drug accumulation during continuous infusion.
What is the significance of understanding context-sensitive half-time (CSHT) in clinical anesthesia?
Understanding CSHT helps in optimizing drug dosing and minimizing the risk of drug accumulation or toxicity during anesthesia.
What role does context-sensitive half-time (CSHT) play in determining the dosing regimen for continuous infusions?
CSHT helps in determining the dosing interval and rate for continuous infusions to achieve desired drug concentrations.
True or False: Context-sensitive half-time (CSHT) is only applicable to intravenous drug administration.
False
What are the limitations of context-sensitive half-time (CSHT) in clinical practice?
CSHT does not account for drug interactions, tissue distribution, or individual patient variability.
What is the practical implication of a shorter context-sensitive half-time (CSHT) for a drug during continuous infusion?
A shorter CSHT allows for faster adjustments in drug dosing to achieve desired effects or prevent toxicity.
What is the relationship between context-sensitive half-time (CSHT) and drug half-life?
CSHT is influenced by drug half-life, but it is not equivalent to half-life as it reflects the changing pharmacokinetics during continuous infusion.
What is the primary benefit of considering context-sensitive half-time (CSHT) in anesthesia practice?
The ability to tailor drug dosing regimens to individual patients based on their pharmacokinetic profiles.
Fill in the blank: Context-sensitive half-time (CSHT) provides a more accurate estimate of drug ___________ during continuous infusion than traditional pharmacokinetic parameters.
accumulation
How does the volume of distribution (Vd) affect context-sensitive half-time (CSHT) of a drug?
A larger volume of distribution results in a longer CSHT as the drug is distributed more widely in the body.
What is the significance of considering context-sensitive half-time (CSHT) in drug administration outside of anesthesia?
CSHT is important in various clinical settings to optimize drug dosing and prevent adverse effects of continuous infusions.
In the context of context-sensitive half-time (CSHT), what does the term ‘context-sensitive’ refer to?
The changing pharmacokinetics of a drug during continuous infusion, which affect its elimination and distribution in the body.
How does the rate of infusion affect context-sensitive half-time (CSHT) of a drug?
A higher rate of infusion can lead to a shorter CSHT as the drug is delivered more rapidly into the body.
What is the primary advantage of using context-sensitive half-time (CSHT) in clinical practice?
The ability to predict and adjust drug concentrations more accurately during continuous infusions based on individual patient factors.
