PSC 4215 - Exam 2 - PLP Plasma Proteins

What effect does increased plasma protein binding have on drug distribution?

It decreases the volume of distribution; more drug stays in plasma.

True or False: Both free and bound drugs can exert effects.

False — only free drugs are active.

What is the formula for fraction unbound?

[Unbound] ÷ [Total drug]

If a drug is 90% unbound, where is it likely found?

In tissue — it has a higher volume of distribution and is likely tissue-bound.

Warfarin is 0.5% unbound. Where is it mostly located?

In plasma — it has low volume of distribution and is bound to albumin.

True or False: Unbound drugs increase overdose risk.

True — free drugs are active.

If all drug is albumin-bound, where does it primarily stay?

In the vascular compartment.

When can plasma proteins cross into tissues?

During inflammation, when vascular permeability is increased.

Which types of drugs bind to albumin versus glycoproteins?

• Acidic drugs bind to albumin

• Basic drugs bind to glycoproteins/lipoproteins.

What is the effect of protein binding on the concentration-time curve versus the effect curve?

There is no change on the concentration-time curve; there is decreased intensity and increased duration on the effect curve.

How does protein binding affect the onset and duration of drug effects?

It decreases onset and increases duration.

True or False: Inactive drugs do not bind plasma proteins.

False — inactive drugs can bind but exert no effect.

What is the effect of nephrotic syndrome on albumin-bound drugs?

It causes loss of albumin and drug, leading to decreased effect.

What happens when one drug displaces another from albumin?

There is an increase in free drug which can lead to increased effect or faster elimination.

True or False: α1-acid glycoprotein binds fewer drugs than albumin.

True — α1-acid glycoprotein is easier to saturate bc it has fewer binding sites

What kind of drugs bind to lipoproteins?

Basic, lipophilic drugs.

What is the effect of increased α1-acid glycoprotein levels on basic drugs?

It increases binding and decreases effect.

What is the relationship between plasma protein binding and free drug concentration?

It is an inverse relationship.

True or False: The plasma concentration-time curve includes both bound and unbound drug.

True — but mostly bound drug is measured.

Why do low-binding drugs have steeper negative slopes on the concentration-time curves?

There is more unbound drug which leads to faster elimination.

True or False: High protein binding leads to more effect and faster elimination.

False — high protein binding sequesters the drug, leading to less effect.

What maintains the balance between bound and unbound drug?

Tissue pulls drug off protein as needed

True or False: A fast-acting drug is either unbound or lipophilic.

True — it reaches its target quickly.

How should you adjust dosing for a highly protein-bound drug in low-albumin states?

You should lower the dose to reduce the risk of toxicity due to increased free drug.