T1/2, Vd, Cl relationships

What is AUC?

Area under the curve

What does the AUC represent?

Total drug exposure (concentration and duration)

What is AUC proportional to?

Dose

What happens to AUC if you double the dose?

It double

What is the unit of AUC?

time * mass / volume

If an animal is in organ failure and the half-life doubles what happens to the AUC?

It doubles

What is the significance of using AUC?

Therapeutic efficacy

Drug toxicity

Bioavailability

Bioequivalence

What happens to drug toxicity as AUC increases?

It goes up

What are the 2 main factors affected bioavailability?

Not absorbed

First pass effect

CMAX is proportional to what?

Dose (double dose double CMAX)

What is TMAX proportional to?

Nothing (TMAX is constant despite dosage)

What is the relationship of half-life and clearance?

Inversely proportional

How do you create a sustained release product?

It looks like a change in Vd, but its actually a decreased absorption rate

When you look at a drug concentration over time graph what causes the initial steep decrease?

There is a combination of normal elimination with a short period of drug distribution into tissues

What is a biphasic plasma concentration?

When there are two different slopes on a chart of drug concentration over time

What does an AUC graph represent?

How high the concentration gets and how long it is present for

How is AUC correlated to therapeutic efficacy?

Fluoroquinolone efficacy is correlated to the ratio of AUC to the MIC

How can aminoglycosides be used to determine the health of the kidneys?

As AUC increases the risk of nephrotoxicity increases

How can AUC be used to determine different bioavailabilities of drugs based on administration methods?

You find the AUC of IV and whatever method you want and compare them

What does relative bioavailability compare?

The brand name vs a generic drug

What is CRI?

Constant rate infusion

What is the purpose of CRI?

Maintain steady plasma concentrations

Its important to maintain a steady plasma concentration for what kinds of drugs?

Anticonvulsants

Analgesics

Anesthesia

Antiarrhythmics

A plasma concentration graph of a drug thats given with CRI looks like what?

No peaks or troughs

Learn all the different formulas he has up on slides

Dont be lazy

Why do you use a loading dose to get to steady state?

Because it will take several half lives to get to steady state if you dont do an initial loading dose

When are loading doses most important?

There is a long half life or when there needs to be an immediate effect