pharm Introduction to Pharmacology unit 1

The Study of Drugs = Pharmacology

is the study of drugs and how they affect the body.

What is a Drug?

A drug is a chemical substance that can change how the body works.

Where do drugs come from?

Drugs can be made from:

🌱 Plants – Example: aspirin originally came from willow tree bark.

🐍 Animals – Some medicines are made from animal products.

🧪 Chemical synthesis – Scientists make drugs in laboratories using chemicals.

🧬 Biotechnology/Recombinant DNA technology – Scientists use living cells, bacteria, or DNA to produce medicines like insulin.

FDA Definition of a Drug

According to the FDA , a drug is something used to:

• Diagnose a disease (find out what disease someone has)

• Cure a disease (get rid of it)

• Relieve symptoms (make a person feel better)

• Treat a disease (help manage it)

• Prevent a disease (stop it from happening)

"Produces a Change in Function" Means:

A drug causes the body to do something different.

Examples:

• Pain medicine → decreases pain.

• Insulin → lowers blood sugar.

• Allergy medicine → reduces allergy symptoms.

• Caffeine → makes you feel more awake.

Drug

a chemical that changes how the body works.
It can come from plants, animals, laboratories, or biotechnology.
Drugs are used to diagnose, cure, treat, relieve, or prevent disease and they cause some kind of change in the body's function.

Pharmacokinetics- AD

What the BODY does to the DRUG

Think: "The drug is taking a trip through the body."

The drug goes through ADME :

A = Absorption

How the drug gets into the blood.

Example:

• You swallow a pill.

• The drug is absorbed from your stomach/intestines into your bloodstream.

D = Distribution

Where the drug travels in the body.

Example:

• The blood carries the drug to your brain, heart, muscles, and other tissues.

Pharmacokinetics- ME

M = Metabolism

How the body changes or breaks down the drug.

Example:

• The liver acts like a chemical factory and breaks down many drugs.

E = Excretion

How the drug leaves the body.

Example:

• The kidneys remove the drug through urine.

Pharmacokinetics- ADME

A Drug Moves Everywhere

1. Absorption → Gets in

2. Distribution → Moves around

3. Metabolism → Broken down

4. Excretion → Gets out

Pharmacodynamics

What the DRUG does to the BODY

Think: "What effect does the drug have?"

Examples:

• Aspirin → reduces pain.

• Insulin → lowers blood sugar.

• Antibiotics → kill or stop bacteria.

• Caffeine → makes you feel more awake.

Pharmacodynamics- MOA

MOA = How the drug works.

Examples:

• Insulin's MOA → helps glucose move into cells.

• Antibiotic's MOA → damages bacteria or stops them from growing.

• Pain medicine's MOA → blocks pain signals.

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Pharmacokinetics vs Pharmacodynamics

Term	Easy Meaning
Pharmacokinetics	What the body does to the drug
ADME	Absorption, Distribution, Metabolism, Excretion
Pharmacodynamics	What the drug does to the body
MOA	How the drug works

Pharmacokinetics = Drug's journey (ADME).
Pharmacodynamics = Drug's effect.
MOA = How the drug causes that effect.

Pharmacotherapeutics

Studies how drugs help treat diseases or conditions .

ex: Using antibiotics to treat an infection.

Pharmacy

The science of making, preparing, and giving out medicines .

ex: A pharmacist fills your prescription and explains how to take it.

Posology

Studies how much medicine (dose) a person needs to obtain the desired effect.

• study of amount of drug required to produce a therapeutic effect, dosing

ex:Deciding whether a patient needs 250 mg or 500 mg of a drug.

Toxicology

Studies the harmful or poisonous effects of drugs and chemicals .

ex: Learning what happens if someone takes too much medication.

Pharmacotherapeutics

"Which drug will help treat the illness?"

Treatment

Treat the disease

Pharmacy

"Prepare and give the medicine."

Preparing & dispensing drugs

Prepare the medicine

Posology

"How much medicine should be given?"

Dose

Choose the dose

Two Pharmacology Principles:

Drugs do not create function, they only modify it.

A drug cannot make your body do something it was never able to do .

Instead, a drug changes, increases, decreases, or helps a normal body function .

Examples:

💓 Heart medicine → helps the heart beat better, but doesn't create a heart.

💉 Insulin → helps the body use sugar correctly, but doesn't create a new body function.

Easy Study Definition:

Drugs modify existing body functions; they do not create new functions.

Two Pharmacology Principles:

. "No drug has a single action."

When a drug enters the body, it usually affects more than one thing .

A drug has:

• A desired effect (what we want it to do)

• Other effects (some helpful, some unwanted)

Example:

Benadryl (allergy medicine)

• Desired effect → reduces allergy symptoms

• Other effect → makes you sleepy

So the drug is doing more than one thing.

Easy Study Definition:

Every drug produces multiple effects in the body, not just one.

Two Pharmacology Principles

Side Effects

A …. is an effect of the drug that is not the main reason you are taking it .

Examples:

• Antibiotic → may cause nausea.

• Allergy medicine → may cause drowsiness.

• Pain medicine → may cause constipation.

The main effect is wanted, but the side effect is an extra effect.

Easy Study Definition:

Side effects are secondary or unwanted effects that occur in addition to the desired effect.

🔀 Every drug has multiple actions

Drug Uses: Therapeutic Use

means treatment .

What it means:

Drugs are used to control symptoms or cure a disease or condition .

Examples:

💊 Antibiotics → treat bacterial infections.

😌 Anti-anxiety medication → helps reduce anxiety.

🤕 Pain medicine → helps reduce pain.

Easy Study Definition:

… use = using a drug to treat or control a disease, condition, or symptom.

Drug Uses: Preventative Use = To Prevent

means stop something before it happens.

What it means:

Drugs are used to prevent a disease or condition from occurring.

Examples:

💉 Vaccines → help prevent diseases.

💊 Some medications can prevent blood clots or infections.

Easy Study Definition:

… use = using a drug to prevent disease or symptoms before they occur

Diagnostic Use = To Find a Disease

Drug Uses

means helping doctors identify or detect a disease.

What it means:

Some drugs or chemicals help doctors see what's happening inside the body.

Examples:

🩻 Contrast dye used in CT scans or MRIs helps certain organs or blood vessels show up more clearly.

Easy Study Definition:

…= using a drug or substance to help detect or diagnose a disease.

Detect

Professionals Administering Drugs

• MD/ Medical Doctor

• Dentists

• RN

• LVN

• EMS/ Emergency Medical Services/Paramedics

• PA/ (Physician Assistant)

• NP

• Medication aide

• Surgical/radiology technicians

• RT/ Respiratory Therapist)

• Unlicensed trained individuals under supervision of licensed personnel- some trained workers may give certain medications while supervised by licensed healthcare personnel.

"Professionals Administering Drugs" mean

means giving medication to a patient safely and correctly .

➡The trained people who are allowed to give medications to patients.

Why is this important?

Medicines can help people, but they can also be dangerous if given incorrectly.

These professionals are trained to:

• Give the correct drug

• Give the correct dose

• Give it to the correct patient

• Watch for side effects

• Make sure it is safe

Important Facts about Medications

• What to know prior to administering a drug:

  • use

  • correct dose/form

  • methods of administration

  • side effects/adverse effects

  • drug interactions

  • precautions/contraindications

  • symptoms of overdose

  • evidence and control of abuse

  • patient allergies

What to Know Before Administering a Drug

1-3

1. Use

Why is the patient taking this drug?

• What disease or symptoms does it treat?

• What is it supposed to do?

Example: Antibiotics are used to treat bacterial infections.

Easy word: Purpose

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2. Correct Dose/Form

How much should be given, and what form should it be in?

• Dose = amount of medication

• Form = pill, liquid, injection, cream, etc.

Example: A patient may need 500 mg as a tablet, not a liquid.

Easy word: Amount

3. Methods of Administration

How should the drug be given?

Examples:

• By mouth (oral)

• Injection

• Inhaler

• Eye drops

• Skin cream

Easy word: Route

What to Know Before Administering a Drug

4-6

4. Side Effects/Adverse Effects

What unwanted effects could happen?

Examples:

• Drowsiness

• Nausea

• Rash

Easy word: Extra effects

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5. Drug Interactions

Can this drug react with other drugs?

Sometimes two medications together can:

• Make a drug stronger

• Make it weaker

• Cause harmful effects

Easy word: Drug + Drug Problems

6. Precautions/Contraindications

When should the drug be used carefully or not at all?

• Caution = be careful

• Contraindication = do not use

Example: Some drugs should not be taken during pregnancy.

Easy word: Warnings

What to Know Before Administering a Drug

7-9

7. Symptoms of Overdose

What happens if too much is taken?

Healthcare workers need to know the warning signs.

Examples:

• Trouble breathing

• Extreme sleepiness

• Confusion

Easy word: Too much medicine

8. Evidence and Control of Abuse

Can the drug be misused or become addictive:

Some drugs can be abused if not used properly.

Examples:

• Opioid pain medications

• Certain anxiety medications

Easy word: Misuse risk

9. Patient Allergies

Is the patient allergic to the medication?

Giving a drug to a patient is allergic to can be dangerous.

Examples:

• Penicillin allergy

• Sulfa allergy

Easy word: Allergy check

What to Know Before Administering a Drug

side by side

Know Before Giving Drug	Easy Meaning
Use	Why give it?
Correct Dose/Form	How much and what type?
Method of Administration	How is it given?
Side Effects	What unwanted effects can happen?
Drug Interactions	Does it react with other drugs?
Precautions/Contraindications	Any warnings or reasons not to use it?
Symptoms of Overdose	What happens if too much is taken?
Evidence and Control of Abuse	Can it be misused?
Patient Allergies	Is the patient allergic?

Rights

They are a safety checklist that healthcare workers use to make sure the right patient gets the right medicine safely.

Easy Way to Think About It

Before giving a medication, ask:

"Am I giving the right medicine to the right person in the right way?"

rights list

• Right patient

• Right medication

• Right dosage

• Right time

• Right route of administration 

• Right form

• Right response 

• Right documentation

RIGHT 1-4

1. Right Patient 👤

Make sure the medication is being given to the correct person .

2. Right Medication 💊

Make sure you have the correct drug .

3. Right Dosage 📏

Give the correct amount of the medication.

4. Right Time ⏰

Give the medication at the correct time .

5. Right Route of Administration 🩺

Give the medication the correct way .

Examples:

• By mouth (oral)

• Injection

• 6. Right Form 💊🥄

Use the correct form of the medication.

Examples:

• Tablet

• Capsule

7. Right Response ✅

Check that the medication is doing what it is supposed to do.

Example:

Pain medicine should help reduce pain.

8. Right Documentation 📝

Write down:

• What drug was given

• When it was given

• How much was given

right side by side chart

Right	Easy Meaning
Right Patient	Right person
Right Medication	Right medicine
Right Dosage	Right amount
Right Time	Right schedule
Right Route	Right way
Right Form	Right type
Right Response	Did it work?
Right Documentation	Write it down

Effects of Drugs

1. Therapeutic Effect ✅

What it means:

This is the desired effect — the reason the drug was given.

Example:

💊 Antibiotic → kills bacteria and treats an infection.

😌 Anti-anxiety medication → reduces anxiety.

This is the good effect we want.

Easy Study Definition:

….= the wanted effect of the drug.

Keyword: WANT

Effects of Drugs

Drug Indication

What it means:

The indication is the reason the drug is used.

Example:

• Antibiotic indication = bacterial infection

• Pain medicine indication = pain

Easy Study Definition:

Indication = what the drug is used for.

Keyword: USE

Effects of Drugs

Contraindication 🚫

What it means:

A reason the drug should NOT be used.

Example:

A person allergic to penicillin should not receive penicillin.

Easy Study Definition:

Contraindication = do not use.

Keyword: DON'T

Effects of Drugs

2. Side Effect ⚠

What it means:

An extra unwanted effect that happens along with the therapeutic effect.

Usually not dangerous, just annoying.

Examples:

😴 Drowsiness

👄 Dry mouth

🤢 Mild nausea

Easy Study Definition:

Side Effect = unwanted but usually not harmful.

Keyword: EXTRA

Effects of Drugs

3. Adverse Effect 🚨

What it means:

An unwanted effect that may be more serious or harmful.

Example:

A drug causes severe dizziness or nervous system problems.

(CNS = Central Nervous System = brain and spinal cord.)

Easy Study Definition:

…= harmful unwanted effect.

Keyword: HARMFUL

Effects of Drugs

4. Toxic Effect ☠

What it means:

The drug has become poisonous to the body.

This can happen if:

• Too much drug is taken

• The drug builds up in the body

Examples:

• Drug overdose

• Organ damage from a medication

Easy Study Definition:

Toxic Effect = poisonous or life-threatening effect.

Keyword: POISON

Easy Order from Best to Worst

effects of drugs

✅ Therapeutic Effect = Wanted

⚠ Side Effect = Unwanted but usually mild

🚨 Adverse Effect = Harmful

☠ Toxic Effect = Poisonous or life-threatening

effects of drugs side by sude chart

Term	Easy Meaning	Keyword
Therapeutic Effect	Effect you want	WANT
Indication	Why the drug is used	USE
Contraindication	When not to use it	DON'T
Side Effect	Extra unwanted effect	EXTRA
Adverse Effect	Harmful unwanted effect	HARMFUL
Toxic Effect	Poisoning/life-threatening effect	POISON

Effects of Drugs 2

1. Lethal Effect ☠

causes death.

A lethal effect is a drug effect that is so severe that it kills the person.

Easy Study Definition:

Lethal Effect = an effect that causes death.

Keyword: DEATH

Effects of Drugs 2

2. Allergic Reaction 🤧

What it means:

An allergic reaction happens when the body's immune system mistakenly thinks a drug is dangerous and attacks it.

Step 1: First Exposure (Sensitization)

Allergic Reaction 🤧

The first time a person takes a drug:

• The immune system notices the drug.

• The body may make antibodies against it.

• Usually there is little or no reaction yet.

This is called sensitization .

Easy Definition:

Sensitization = the body learns to recognize the drug and prepares antibodies.

2. Allergic Reaction 🤧

Step 2: Later Exposure

The next time the person takes that drug:

• The antibodies recognize it.

• The immune system reacts.

• An allergic reaction occurs.

This is called an antigen-antibody reaction .

Easy Definition:

Antigen = the drug or substance causing the allergy.

Antibody = the body's defense protein that reacts to it.

Common Allergic Symptoms

🤕 Rash = red irritated skin

🐝 Hives = raised itchy bumps

🤚 Itching = skin feels itchy

👃 Nasal congestion = stuffy nose

⬇ Hypotension = low blood pressure

🫁 Bronchoconstriction = airways become narrow, making breathing harder

Easy Study Definition:

Allergic reaction = the immune system overreacts to a drug.

Anaphylaxis 🚨 (Medical Emergency)

a severe, life-threatening allergic reaction.

The reaction happens very quickly and can affect the whole body.

Symptoms:

🫁 Respiratory difficulty

• Trouble breathing

⬇ Decrease in blood pressure

• Blood pressure drops dangerously low

❤ Cardiac arrest

• The heart stops beating normally

☠ Death

• Can occur if not treated immediately

Easy Study Definition:

… = a severe allergic reaction that can cause breathing problems, low blood pressure, and death.

Effects of Drugs 2

lethal effect summary

First Time:

Drug → Body learns it → Antibodies form (Sensitization)

Next Time:

Drug → Antibodies react → Allergy symptoms

Worst Case:

Anaphylaxis → Trouble breathing + Low blood pressure + Possible death

Effects of Drugs 3

1. Iatrogenic Effect 🏥

is a problem or illness that is caused by medical treatment or a drug.

The healthcare provider is trying to help the patient, but an unwanted problem happens.

Example:

• A patient takes an antibiotic.

• The antibiotic causes a severe yeast infection.

The doctor didn't mean for this to happen, but it resulted from the treatment.

Easy Study Definition:

…. = an unintentional problem caused by medical treatment or a drug.

Keyword:

Treatment-caused

Effects of Drugs 3

2. Idiosyncratic Effect 🤷

is a strange or unusual drug reaction that happens in one person and is not expected.

Most people do not react this way.

Example:

A medication usually makes people sleepy, but one person becomes very energetic and hyper.

That's an idiosyncratic effect because it's unusual and unique to that individual.

Easy Study Definition:

… Effect = an unexpected drug reaction that is unique to a particular person.

Keyword:

Unusual

Iatrogenic Effect vs

Idiosyncratic Effect

Term	Easy Meaning	Keyword
Iatrogenic Effect	Problem caused by treatment or a drug	Treatment-caused
Idiosyncratic Effect	Strange, unexpected reaction unique to one person	Unusual

Iatrogenic Effect

Problem caused by treatment or a drug

Treatment-caused

👨‍⚕ "The treatment caused the problem."

Example:
Drug → unwanted illness

effects are unwanted problems caused by treatment

Idiosyncratic effect

Strange, unexpected reaction unique to one person

Unusual

🤷 "This person reacted differently than everyone else."

Drug → weird, unexpected reaction

effects are unusual and unexpected reactions that occur in a specific individual

1. Dose 💊

The dose is the exact amount of medication given to a patient.

Example:

• 500 mg of Tylenol

• 1 tablet of an antibiotic

What does this quote mean?

"Only the dose separates a drug from a poison."

This means:

✅ The right amount can help you.

❌ Too much can harm you.

Example:

Water is good for you, but drinking an extreme amount can be dangerous.

Medicines are the same way:

• Correct dose = therapeutic effect

• Too much = toxic effect (poisoning)

Easy Study Definition:

…. = the amount of drug given.

Keyword: HOW MUCH?

2. Site of Action 🎯

What it means:

The… is the place in the body where the drug works.

Example:

Aspirin helps reduce fever by acting on the hypothalamus (the body's temperature-control center in the brain).

Think of it like this:

The drug travels through the body and reaches its "workplace."

That workplace is the…

Easy Study Definition:

….= where the drug works in the body.

Keyword: WHERE?

3. Mechanism of Action (MOA) ⚙

What it means:

The …. explains how the drug produces its effect.

Example:

Anesthetics reduce pain by interrupting nerve signals.

SW:

• Site of Action = nerves

• MOA = blocks/interferences with nerve conduction

Another Example:

Insulin lowers blood sugar.

• Site of Action = body cells

• MOA = helps glucose move into cells

Easy Study Definition:

MOA = how the drug works.

Keyword: HOW?

side by side

Dose,

Site of Action MOA

Term	Question It Answers	Easy Meaning
Dose	How much?	Amount of drug given
Site of Action	Where?	Location where the drug works
MOA	How?	How the drug causes its effect

Imagine a drug as a worker:

💊 Dose = How many workers were sent?

🎯 Site of Action = Where is the job site?

⚙ MOA = How do the workers do the job?

2. Affinity 🤝

What it means:

… describes how strongly a drug wants to attach to a recipient.

Some drugs bind very tightly.

Some drugs bind only weakly.

Example:

• High affinity = strong attraction to the receptor

• Low affinity = weak attraction to the receptor

Easy Way to Think About It:

Imagine a magnet.

🧲 Strong magnet = high affinity

🧲 Weak magnet = low affinity

Easy Study Definition:

… = how strongly a drug binds to a receptor.

Keyword: STRENGTH OF BINDING

3. Lock and Key 🔑

What it means:

A drug must have the correct shape to fit the receptor.

If the drug fits, it can produce an effect.

If it doesn't fit, it won't work on that receiver.

Example:

🔒 Lock = receiver

🔑 Key = drug

Correct key → lock opens → drug effect occurs

Wrong key → lock doesn't open → no effect

Easy Study Definition:

Lock and Key = the drug must fit the receptor to work.

Keyword: FIT

How They Work Together

• Receptor Site:  

• Affinity

• Lock and Key: 

• Drug travels through the body.

• Drug finds a receptor site (lock).

• Drug must fit the receiver (key).

• The drug binds.

• The strength of binding is called affinity .

• The drug produces an effect.

Term	Easy Meaning	Keyword
Receptor Site	Place where drug attaches	LOCK
Affinity	How strongly drug binds	STRENGTH
Lock and Key	Drug must fit receptor	FIT

Receptor site

the whole protein; receptor site = the specific spot on that protein where the drug binds.

lock

• specific location on the site of action where the drug binds to a cell in order to cause an effect

• i.e. beta-1 receptors on the heart, opioid receptors in the brain