IPA 3125 - Class 2 - Pharmacokinetics vs pharmacodynamics

_________ sometimes described as what the body does to a drug, refers to the

movement of a drug into, through, and out of the body

Pharmacokinetics

_________ described as what a drug does to the body, involves receptor binding,

post-receptor effects, and chemical interactions.

Pharmacodynamics

Drug pharmacokinetics determines what three descriptions of a drug’s effects?

______ _________ is determined by the drug’s physicochemical properties, formulation, and route

of administration.

Drug absorption

The molecular changes that occur when a drug binds to a receptor and alters cellular activity are called ______.

Drug action

The physiological (body) and psychological (mind) changes that occur after taking a drug are called ______.

Drug effects

Drug action begins when a drug molecule binds to a ______ on or in a cell, triggering ______ changes.

Receptor; molecular

What is a receptor, and what happens when a drug molecule binds to it?

A receptor is a molecule on or in a cell that a drug can bind to. This interaction can change cellular activity.

The chemical and cellular changes triggered when a drug binds to a receptor are called ______.

Drug action

When a drug crosses the blood-brain barrier, it can bind to receptors on ______, triggering chemical changes.

Neurons

The chemical changes triggered by a drug can spread through connected neurons in a ______ effect.

Cascade

n psychopharmacology, studying drug action involves examining which ______ are affected and how their activity changes.

Neurotransmitters

he intended beneficial changes produced by a medication are called ______ effects.

Therapeutic

When an antidepressant improves a person's mood, this is an example of a ______ effect.

Therapeutic

Whether a drug effect is considered therapeutic depends partly on whether it is the ______ outcome being sought.

Desired

Drug effects that are generally unwanted or not being sought by the person taking the substance are called ______ effects.

Side

Dry mouth, dry eyes, and increased anxiety after cannabis use are examples of possible ______ effects.

Side

Some stimulants were initially used for weight loss, but their effects on attention and energy later became desirable. In this example, weight loss shifted toward being a ______ effect.

Side

When a drug causes a change in behavior, and that change leads to further effects on a person's daily life or lifestyle, these indirect effects are called ______ effects.

Nonspecific

If a drug suppresses appetite, causing someone to eat less and subsequently changing their daily lifestyle, the lifestyle changes are examples of ______ effects.

Nonspecific

A researcher examines which receptors a drug binds to and how it changes neuronal activity. The researcher is studying drug ______.

Action

A researcher examines changes in mood, alertness, heart rate, and behavior after a person takes a medication. The researcher is studying drug ______.

Effects

A medication produces the desired improvement in mood but also causes nausea. The improvement is the ______ effect, while the nausea is a ______ effect.

Therapeutic; side

A medication causes a person to feel less hungry, leading them to change their eating habits. The reduced appetite is a drug ______, while the resulting lifestyle changes may be ______ effects.

Effect; nonspecific

Pharmacokinetics is the study of what the ______ does to a drug, including its absorption, distribution, metabolism, and excretion.

Body

The way a drug enters the body, such as by swallowing it or injecting it, is its route of ______.

Administration

The process by which a drug enters the bloodstream from its site of administration is called ______.

Absorption

When a drug is administered, not all of it may reach the bloodstream. The percentage that reaches the bloodstream in an unchanged form is called ______.

Bioavailability

After a drug enters the bloodstream, the process of its movement throughout the body and to different tissues is called ______.

Distribution

Front: The process by which the body chemically changes a drug, often using enzymes in the liver, is called ______.

Metabolism

The process by which a drug leaves the body, mainly through urine or feces, is called ______.

Excretion

The ____ ____ _____ affects whether substances in the bloodstream can enter the brain.

blood-brain barrier

Pharmacodynamics is the study of what a ______ does to the body.

Drug

The process through which drugs affect communication between neurons is called ______.

Neurotransmission

The relationship between the amount of a drug taken and the resulting effect is called the ______-response relationship.

Dose

A drug's effects and side effects may change depending on the ______ administered.

Dose

When two or more substances affect one another's actions or effects in the body, this is called a drug ______.

Interaction

Pharmacokinetics examines how the body absorbs, distributes, metabolizes, and ______ a drug.

Excretes

Pharmacodynamics examines how a drug affects the body, including neurotransmission, dose-response, and drug ______.

Interactions

A researcher studies how quickly a medication reaches the bloodstream and how the liver breaks it down. This is ______.

Pharmacokinetics

A researcher studies how increasing a medication's dose changes its effects on mood and alertness. This is ______.

Pharmacodynamics

What is the key difference between pharmacokinetics and pharmacodynamics?

Pharmacokinetics studies how the body processes a drug, while pharmacodynamics studies how a drug affects the body.

Four factors that can influence how a drug is processed by the body are its chemical composition, ______, ______ ______, and ______ ________.

Dose; usage history; personal characteristics

Personal characteristics such as age, ______ ________, genetics, and liver or kidney function can affect how a drug is absorbed, distributed, metabolized, or excreted.

Body composition

With repeated use of a drug, a person may develop ______, meaning the same dose produces a weaker effect over time.

Tolerance

Bioavailability is the percentage of an administered drug dose that reaches the bloodstream in an ______ form.

Unchanged

Absolute bioavailability compares the amount of a drug reaching the bloodstream through a particular route of administration with ______ ______ administration.

IV (intravenous) injection

Intravenous administration typically has close to ______% bioavailability because the drug is injected directly into the bloodstream.

100

Relative bioavailability compares how much of a drug reaches the bloodstream through ______ different routes of administration.

Two

______ bioavailability compares how much of the same drug reaches your bloodstream when taken in two different ways, such as swallowing it versus smoking it.

Swallowing it: 40% reaches the bloodstream.
Smoking it: 80% reaches the bloodstream.

Relative

When two drug administrations have a bioavailability difference of less than ______%, they are considered bioequivalent

20

The first-pass mechanism occurs when an absorbed drug passes through the ______ before reaching the general bloodstream, where some of the drug may be broken down.

Liver

The first-pass mechanism can reduce bioavailability because some of the drug is ______ before reaching the general bloodstream.

Metabolized
(chemically changed)

The first-pass mechanism helps the body process substances and ______ potential toxins, but it can also reduce the amount of a drug available in the bloodstream.

Filter

The rate of drug elimination affects bioavailability because the faster a drug is removed from the bloodstream, the ______ the amount that remains available.

Lower

The two major organs involved in drug elimination are the ______ and the ______.

Liver; kidneys

Bioavailability is influenced by the route of administration, first-pass metabolism, and the rate of drug ______.

Elimination

After a drug dose is taken, its blood concentration initially rises as ______ occurs. Later, the concentration falls as ______ exceeds absorption.

Absorption; elimination

What does the peak of a drug concentration–time curve represent?

The highest concentration of the drug in the bloodstream (Cmax)

A drug has a half-life of 4 hours. After 4 hours, approximately what percentage of the drug concentration present at the start of that period remains in the bloodstream?

50%

Knowing a drug's half-life helps determine how often to take it and how long it takes for the drug to be mostly ______ from the body.

Eliminated

A half-life is how long it takes for the amount of a drug in your ______ to drop by half.

For example, if you start with 100 units of a drug:

• After 1 half-life: 50 units remain.

• After 2 half-lives: 25 units remain.

• After 3 half-lives: 12.5 units remain.

• After 5 half-lives: about 3 units remain.

Each half-life cuts the remaining amount in half. That's why it takes several half-lives for a drug to be mostly eliminated.

bloodstream

The “rule of 5” states that it generally takes about 5 ____ ____ to reach steady state with regular dosing.

half-lives

Steady state occurs when the amount of drug entering the bloodstream over time balances the amount being ______.

Eliminated

Slower drug elimination generally results in a ______ half-life.

Longer

Faster drug elimination generally results in a ______ half-life.

Shorter

A higher volume of distribution is generally associated with a ______ half-life, assuming other relevant factors remain constant.

Longer

_____ ___ _____ describes how widely a drug spreads throughout the body compared with how much of it remains in the bloodstream.

Volume of distribution

Volume of distribution describes how widely a drug spreads from the bloodstream into the body's ______.

Tissues

A drug that spreads more widely into body tissues generally has a ______ volume of distribution.

Higher

Half-life is important when prescribing medication because it helps guide dosing intervals, time to steady state, and the risk of drug ______.

Toxicity

The concentration of a drug decreases over time as the body ______ it through processes such as metabolism and excretion.

Eliminates

A drug's effects are strongly influenced by its ______, which determines how much of the drug reaches the bloodstream unchanged.

Bioavailability

Which pharmacokinetic factor describes how quickly a drug enters the bloodstream?

Rate of absorption

The five ________ factors affecting bioavailability include route of administration, rate of absorption, distribution, metabolism, and elimination.

pharmacokinetic

Enteral routes of administration deliver drugs through the ______ system.

Digestive

Name two enteral routes of drug administration.

Oral (mouth) and rectal

Enteral routes can have variable bioavailability because absorption and ______ metabolism can vary.

First-pass

______ routes of administration bypass the digestive tract, such as injections.

Parenteral

Compared with enteral routes, parenteral routes generally involve little or no ______ metabolism.

First-pass

Bioavailability is generally easier to control with ______ routes of administration.

Parenteral

______ administration refers to giving a drug through the digestive tract, such as by swallowing it or administering it rectally.

Enteral

Food can cause ______ _____ by slowing a drug's movement through the digestive system.

Delayed absorption

Oral administration can have variable ______ because of digestion, food, and first-pass metabolism.

Bioavailability

Rectal administration has ______ and ______ absorption.

Irregular; unpredictable

After rectal administration, a medication may dissolve and be absorbed by the ______ of the rectum.

Capillaries

Rectal administration can partially ______ first-pass metabolism.

Avoid

The effects of rectal administration are usually ______ than those of oral administration.

Quicker

Inhalation has a very ______ rate of absorption because the lungs have a rich blood supply and are close to the heart.

Fast

After inhalation, effects can begin within a few ______ to a few ______.

Seconds; minutes

he lungs have a rich blood supply because they contain many ______.

Capillaries

Inhalation may be useful when oral administration is too slow or when digestion can ______ a substance.

Destroy