Pharmacodynamics

Chronic use of a drug may cause an increase in enzymes used to metabolize it, need to take more of the drug to get the same effect

Enzyme induction

Some drugs may inhibit some enzymes, which might be beneficial for some health concerns but may have adverse interactions with other drugs

Enzyme Inhibition

MAO-Is inhibit monoamines to treat depression usually, but alcohol could affect the body more now that this inhibition is occuring (so doctors will advise people to not drink alcohol on MAO-Is) What is this an example of?

Enzyme Inhibition

Taking more than one drug that could compete for the same enzyme to be broken down, both drugs can build up in the system more than they individually would affect the body

Competition

Time it takes for ½ the drug to be removed from the system (time to get to steady plasma level, blood concentration)

Half Life of Drugs

Early on in the half-life time there is _____ drug in the system and _____ clearance rate.

more, faster

The more often you take a drug the more ______ the plasma levels and blood concentration

steady

Removal of drug by it’s half-life, when the enzymes are not saturated by the drug

First-order kinetics

Which form of decay is exponential, first-order kinetics or zero-order kinetics?

First-order kinetics

When there is more drug in your system than enzymes that can break it down

Zero-order kinetics

Which form of decay has a steady clearance rate and is non-concentration dependent, first-order kinetics or zero-order kinetics?

Zero-order kinetics

Which form of decay is alcohol and example of? First-order kinetics or zero-order kinetics

Zero-order kinetics

Most drugs that enter the kidneys to be broken down get _____________

reabsorbed into the blood

Since most drugs that enter the kidneys get reabsorbed into the blood, they must be _________________ that is not as likely to be reabsorbed

broken down into a form by the liver

When the liver converts drugs into a form that can be excreted, it makes the drug _____________

less lipid soluble

What are the three measured effects of drugs?

1. Therapeutic effects

2. Side effects

3. Toxicity effects

How well a drug binds to the receptor

Affinity

____ affinity in agonists and _____ affinity in antagonists

high, low

To what degree a drug elicits the response

Efficacy

How much of a drug is needed to elicit a response, based on affinity

Potency

On a dose response curve what is the Y-axis?

% response

On a dose response curve what is the X-axis?

Dose

On a dose response curve what does lower dose mean in terms of the response?

Lower response

On a dose response curve what does higher dose mean in terms of the response?

Higher response

On a dose response curve, how can someone identify the efficacy?

The plateau at the max response

Which side of the dose response curve has higher potency?

Left

Which side of the dose response curve has higher potency?

Left

Which side of the dose response curve has higher affinity?

Left

Different pain relievers have the same response, but one might work better than another is an example of which concept?

Efficacy

Different pain relievers may all relieve pain, but some require a larger amount than others is an example of which concept?

Potency

Dose where 50% of subjects respond with the desired response

ED50

Dose where 50% of subjects respond with an undesired, toxic response

TD50

Dose where 50% of subjects die

LD50

What is the formula for the therapeutic index?

TD50/ED50=LD50

The ______________ is the amount of a drug it is ok to take to get an effect until the toxic effect starts

margin of safety

What is an example of a drug that would cause a non-typical dose-response curve (one that is an inverted U and has both rising and falling phases)?

Melatonin

If we pretreat a drug with a competitive antagonist, _______ potency and need _____ drug to get desired effect.

lower, more

If we pretreat a drug with a non-competitive antagonists, _____ efficacy and ____ of a maximum response.

lower, less

Drugs and antagonists are not competing for binding spots so the drug has a ______ affinity and the more drug you take will just get broken down

lower

Drug interactions reduce each others effectiveness but are not competing on the same receptor

Physiological Antagonism

Drug A + Drug B = larger response than each drug individually

Addictive Effects

Drug A (higher efficacy) + Drug B (lower efficacy) = greater response than what you would expect

Potentiation

How much drug is available

Pharmacokinetics

What does ADME stand for in pharmacokinetics?

Absorption, distribution, metabolism, excretion

How much is active and excreted

Pharmacodynamics

Need more of a drug to get the desired effect

Tolerance

Tolerance is ______ when drug-use stops (drunk faster when you haven’t drank in awhile)

reversible

What are the 3 things tolerance depends on?

1. Dose

2. Context

3. Frequency

Tolerance could occur _____ or after ____ use

rapidly, chronic

Not all _____ of a drug show tolerance

effects

Increasing enzymes in the liver to break down a drug

Metabolic Tolerance

Changing receptors that bind with the drug

Pharmacodynamic Tolerance

Increase receptors

Up-regulation

If an antagonist is blocking receptors for a NT, ________ will help

Up-regulation

Decrease receptors

Down-regulation

If an agonist has an overload of NT trying to bind to a receptor, ___________ will help

Down-regulation

Classical Conditioning

Behavioral Tolerance

Environment determines tolerance, ____ environment = no tolerance

New