Module 7 -Classification of Autonomic Nervous System drugs

1. Sympathomimetics/Adrenergic/Andromimetic

2. Sympatholytic

3. Parasympathomimetic/Cholinergic/Cholinomime tics

4. Parasympatholytic

SSPP

Classification of Autonomic Nervous System drugs

1. Ach

2. NE

• The Cranium and Sacrum are for Chilling (ACh).

• The Thorax and Lumbar are for Threats (Norepinephrine).

2 basic neurotransmitters

Sympathomimetics/Adrenergic/Andromimetic

• Mimics (copy) the action of the sympathetic nerves which neurotransmitter is norepinephrine but the action will depend to which receptor it will bind (α or β).

Sympathomimetics/Adrenergic/Andromimetic

• ______ (___) the action of the _______ nerves which neurotransmitter is __________ but the action will depend to which receptor it will bind (α or β).

Sympathomimetics/Adrenergic/Andromimetic

• Norepinephrine came from the Adrenal Gland, which is normally called as adrenaline.

Sympathomimetics/Adrenergic/Andromimetic

• ______ came from the _______ ______, which is normally called as _______.

1. Receptor-blocking Sympatholytic Drug/ Adrenergic-blocking (competitive)

2. Adrenolytic/Neuronal blocking (noncompetitive)

Sympatholytic 2 types

Sympatholytic

Drugs that inhibits the action of the sympathetic nerve

Sympatholytic

Drugs that ______ the action of the _______ nerve

Receptor-blocking Sympatholytic Drug/ Adrenergic-blocking (competitive)

• Drugs that compete with norepinephrine for the same receptor

Adrenolytic/Neuronal blocking (noncompetitive)

• It cause breakdown of norepinephrine

Receptor-blocking Sympatholytic Drug/ Adrenergic-blocking (competitive)

• Drugs that compete with _______ for the _____ receptor

Adrenolytic/Neuronal blocking (noncompetitive)

• It cause _______ of norepinephrine

Parasympathomimetic/Cholinergic/Cholinomimetics

• Mimics (copy) the action of the parasympathetic

• Receptors are Muscarinic and Nicotinic receptor.

Parasympathomimetic/Cholinergic/Cholinomimetics

• ______ (___) the _____ of the __________

• Receptors are _______ and _______ receptor.

1. Receptor-blocking Parasympatholytic Drug/ Cholinergic-blocking (competitive)

2. Neuronal Blocking Drugs/Anticholinergic (noncompetitive)

Parasympatholytic

2 types

Parasympatholytic

Drugs that inhibits the action of the parasympathetic nerve

Parasympatholytic

Drugs that _______ the action of the _________ nerve

Receptor-blocking Parasympatholytic Drug/ Cholinergic-blocking (competitive)

• Drugs that compete with acetylcholine for the same receptor

Neuronal Blocking Drugs/Anticholinergic (noncompetitive)

• It cause breakdown of acetylcholine

Receptor-blocking Parasympatholytic Drug/ Cholinergic-blocking (competitive)

• Drugs that ______ with _______ for the same receptor

Neuronal Blocking Drugs/Anticholinergic (noncompetitive)

• It cause _______ of ________

• Sympathomimetic (Turn ON Fight)

• Sympatholytic (Turn OFF Fight)

• Parasympathomimetic (Turn ON Rest)

• Parasympatholytic (Turn OFF Rest)

The 4 master switches of the body's autonomic control board.

SSPP = Stop Stressing, Please Pooping. (Sympathetics stop stress/deal with it; Parasympathetics handle GI motility/pooping).

What are the 4 main categories of autonomic pharmacology (the SSPP rule)?

• ____________ (Turn ON Fight)

• __________ (Turn OFF Fight)

• _____________ (Turn ON Rest)

• _______________ (Turn OFF Rest)

Connect each drug class to a physical animal behavior to remember if you are turning ON or OFF the stress and rest responses.

• Sympathomimetic (Mimics Stress) = Startle Snow! Imagine your 2-year-old cat getting spooked and zooming around the house. Full fight-or-flight: pupils dilate, heart races, airways open up.

• Sympatholytic (Blocks Stress) = Soothe Snow. You block the panic. The cat calms down, heart rate drops, and she transitions into a resting state.

• Parasympathomimetic (Mimics Rest) = Peaceful Shih Tzu! Imagine your 12-year-old dog taking a deep, heavy nap after dinner. Ultimate rest-and-digest: slow heart rate, GI tract moving, maybe a little drool (secretions).

• Parasympatholytic (Blocks Rest) = Poke the Shih Tzu! You interrupt the nap and block the rest! The dog wakes up startled, heart rate spikes, and secretions dry up (mimicking a stress response).

Always remember the "criss-cross" effect for your pharmacology exams. Blocking stress (Sympatholytic) looks exactly like resting. Blocking rest (Parasympatholytic) looks exactly like stress!

What is the best mnemonic to remember the effects of the 4 autonomic classes (Sympathomimetic, Sympatholytic, Parasympathomimetic, Parasympatholytic)?

1. Catecholamines

2. Dopamine

3. Fenoldopam

4. Dobutamine

5. Non-catecholamine

6. β2 – selective bronchodilators

Cats Do Find Dogs Naturally Boring (CDFDNB)

enumerate Sympathomimetics Drugs/Adrenomimetic/Adrenergic drugs

Sympathomimetics Drugs/Adrenomimetic/Adrenergic

Mimics (copy) the action of the sympathetic nerves which neurotransmitter is norepinephrine but the action will depend to which receptor it will bind (α or β).

Sympathomimetics Drugs/Adrenomimetic/Adrenergic

Mimics (copy) the action of the sympathetic nerves which neurotransmitter is norepinephrine but the action will depend to which receptor it will bind (α or β).

Sympathomimetics Drugs/Adrenomimetic/Adrenergic

______ (____) the action of the _______ nerves which neurotransmitter is __________ but the action will depend to which receptor it will bind (α or β).

Norepinephrine

came from the Adrenal Gland, which is normally called as adrenaline

Norepinephrine came from the Adrenal Gland, which is normally called as adrenaline.

Norepinephrine came from the _______ _____, which is normally called as ________.

1. Epinephrine

2. Norepinephrine

3. Isoproterenol (synthetic drug)

ENI = Every Nerve Ignites! (These jump-start the body)

What are the drugs under Catecholamines?

➡ Mostly VASOCONSTRICTION

Especially in:

• Skin

• Mucosa

• Kidney

• Mesentery

💡 Mnemonic

"SKiM gets SQUEEZED."

Skin
Kidney
Mesentery

Imagine someone squeezing SKiM milk.

👉 Squeezing = Vasoconstriction

Catecholamines generally cause what effect on blood vessels?

Coronary blood vessels

Catecholamines want the heart to receive more blood during emergencies.

Heart = OPEN vessels.

Which blood vessels are dilated by catecholamines?

Vasodilation of skeletal muscle blood vessels

💡 Mnemonic

Imagine someone suddenly sees a bear.

Your legs need blood to RUN.

Small dose

↓

Blood goes to muscles.

Small dose of epinephrine causes?

🦵 Vasoconstriction of skeletal muscle blood vessels

💡 Mnemonic

Small = Stretch open

Large = Lock closed

Remember:

Small opens.

Large closes.

Large dose of epinephrine causes?

Propranolol

💡 Mnemonic

PRO players BLOCK everything.

Propranolol

↓

Blocks β receptors

↓

Blocks vasodilation.

What blocks epinephrine-induced vasodilation?

INOTROPES

Meaning:

Increase the force of cardiac contraction.

💡 Mnemonic

INO = "I NEED OUTPUT."

More force

↓

More cardiac output

Catecholamines are positive ________.

Heart rate (tachycardia)

💡 Mnemonic

Emergency

↓

Heart goes

🏃💨

"TACHY"

Catecholamines increase ________ by changing pacemaker automaticity.

• Halothane

• Chloroform

💡 Mnemonic

"HALO + CHLORO = Heart HAZARD."

Remember:

These anesthetics

↓

↑ Cardiac rhythm irregularities.

Which anesthetics make the heart more sensitive to catecholamines?

They act as an adjunct.

They constrict blood vessels

↓

Drug stays longer.

💡 Memory Trick

Imagine closing the exit doors.

The anesthetic cannot escape.

Catecholamines + local anesthetic

Why are they given together?

Local hemostatic

↓

Constricts blood vessels

↓

Stops bleeding

💡 Mnemonic

"SQUEEZE to STOP."

Bleeding stops because vessels are squeezed shut.

Why are catecholamines used for epistaxis (nosebleed)?

Epinephrine

💡 Mnemonic

EPI saves EPIC emergencies.

Whenever you see

🚨 Anaphylaxis

Immediately think

➡ EPINEPHRINE

Drug of choice for anaphylaxis (life-threatening acute hypersensitivity reaction)?

Isoproterenol

💡 Mnemonic

ISO = "I Save Output."

Heart blocked?

↓

Use Isoproterenol

Drug of choice for heart block?

Dilate the bronchi.

💡 Mnemonic

Imagine opening a bronchial umbrella.

Open umbrella

=

Open airway.

Catecholamines are used for bronchial asthma because they...

Small dose ➡ Vasodilation

Large dose ➡ Vasoconstriction

Memory Trick

Think of a faucet:

💧 Small turn → Water flows (vessels open)

💥 Full blast → Safety valve shuts (vessels constrict)

Epinephrine on skeletal muscle blood vessels

1. Adjunct with local anesthetic

2. Local hemostatic

3. Hypertension

4. Cardiac arrest

5. Anaphylaxis

6. Bronchial asthma

"A Happy Horse Can Always Breathe."

enumerate what catecholamine treats:

• 2 Major Actions

• 1 Major Treatment

• 3 Contraindications

Dopamine = 2 - 1 - 3

CR

C = Cardiovascular function ❤

R = Renal & Splanchnic beds 🫘

💡 Mnemonic

"DOPA drives the CAR to the RENAL station."

CAR = Cardiovascular

RENAL = Kidney & splanchnic circulation

Dopamine has 2 major actions outside from the brain or Parkinson's disease.

Mnemonic?

Dopamine

BUT...

Dopamine itself cannot cross the blood-brain barrier.

Instead,

↓

α-dopa (L-dopa)

↓

Crosses BBB

↓

Converted into dopamine.

Mnemonic

DOPA needs a DOOR.

The Blood-Brain Barrier is locked.

Only L-dopa (α-dopa) has the key. Inside the brain...

🔑

Drug of choice for Parkinson's disease?

3 Steps

ABC

α-dopa formed

↓

Blood-brain barrier crossed

↓

Converted to dopamine

How does dopamine reach the brain?

Shock

Why?

Shock can cause:

Cardiovascular dysfunction

Renal failure

Dopamine supports both.

💡 Mnemonic

Think

"SHOCK the HEART and KIDNEY."

Dopamine protects both.

Major treatment use of dopamine?

PPH

Phenoxybenzamine > Pressor effect > Blocks α receptor

Propranolol > Stimulatory effect > Blocks β receptor

Haloperidol > Depressor effect in the brain > Blocks β receptor

Mnemonic

PPH

Think

"Please Protect Head."

There are 3 contraindication drugs in dopamine.

Mnemonic?

Blocks α receptor > Pressor effect

Mnemonic

PHENO = PRESSURE

Phenoxy

↓

Pressure ↑

Phenoxybenzamine effect?

Blocks β receptor > Stimulatory effect

Mnemonic

PRO players STIMULATE the game.

Propranolol effect?

Blocks β receptor > Depressor effect in the brain

Mnemonic

HALO = Head goes LOW.

HALOperidol

↓

Brain activity ↓

Haloperidol effect?

2 Actions: CR

• Cardiovascular

• Renal/Splanchnic

1 Treatment: Shock

• (Heart + Kidney)

3 Contraindications: PPH

• Phenoxybenzamine

• Propranolol

• Haloperidol

DOPA = 2 • 1 • 3 BREAKDOWN

Claviceps purpurea

💡 Mnemonic:
CLAVI-CEPS = fungus with big biceps

Imagine a purple fungus flexing its biceps.

Claviceps purpurea → source of Ergot Alkaloids

Ergot Alkaloids come from what fungus?

Vasodilation of vascular beds

💡 Mnemonic

"DA = Dilates Arteries."

Think:

Dopamine receptor

↓

Dilates arteries

(DA → Dilates Arteries)

Activation of the dopamine receptor by Fenoldopam causes what effect?

Hypertension

💡 Mnemonic

"HIGH pressure? Open the pipes!"

Hypertension

↓

Fenoldopam

↓

Vasodilation

↓

Pressure goes down.

Main treatment use of Fenoldopam?

GR

G = Improves GIT perfusion

R = Renal protection from vasoconstriction

💡 Mnemonic

"GR = Gut & Renals"

Fenoldopam has 2 major benefits in treating hypertension.

Mnemonic?

D → V → H → GR

• D = Dopamine receptor

• V = Vasodilation

• H = Hypertension

• GR = Gut perfusion + Renal protection

Fenoldopam in 4 words.

Selectively increases cardiac contractility

💡 Mnemonic

DO-BEAT-amine

Think:

"DO the HEART BEAT harder!"

Dobutamine = Stronger heartbeat

(Contractility ↑)

What is the main effect of Dobutamine?

RB

R = Cardiac Rhythmicity

B = Blood pressure

💡 Mnemonic

"RB = Rhythm & BP"

Dobutamine makes the heart beat stronger, NOT faster and doesn't change BP.

Think:

💪 Stronger

❌ Not faster

❌ No BP change

Dobutamine increases cardiac contractility without affecting what 2 things?

Mnemonic?

Low-output cardiac failure

💡 Mnemonic

"LOW OUTPUT? DO BETTER!"

Think:

Low cardiac output

↓

DO-BUTAMINE

↓

Heart pumps stronger

Main treatment use of Dobutamine?

C → RB → L

• C = Contractility ↑

• RB = Rhythm & Blood pressure unchanged

• L = Low-output cardiac failure

Dobutamine in 4 words.

• DOPAmine = Think "DOPE does MANY jobs." (brain, heart, kidneys, shock)

• DOBUtamine = Think "DO BETTER." It has one main job: make the heart pump stronger without changing its rhythm or blood pressure.

A way to distinguish dopamine from dobutamine:

• 1 Starting Drug

• 2 Pathways

• 3 Contraindication/Key Facts

Think:

"One tree with TWO branches." 🌳

Everything starts from Ephedrine.

Non-Catecholamine = 1 → 2 → 3

Natural catecholamines → Synthetic drugs

The first drug is:

Ephedrine

(an alkaloid from the Chinese shrub Ma Huang)

💡 Mnemonic

"EPH = Entry Point."

Everything starts with Ephedrine.

Non-catecholamines are derived from what?

Ma Huang

(Chinese shrub)

Ephedrine comes from what plant?

AM vs PP

AM Pathway

• Ephedrine > Amphetamine > Methamphetamine > Methoxamine > Metaraminol

PP Pathway

• Ephedrine > Pseudoephedrine > Phenylephrine > Phenylpropanolamine

Mnemonic

AM vs PP

AM = Amphetamine & Methamphetamine branch

PP = Pseudoephedrine & Phenylpropanolamine branch

Ephedrine has 2 pathways.

Mnemonic?

• Ephedrine > Amphetamine > Methamphetamine > Methoxamine > Metaraminol

💡 Mnemonic

AMMM

Amphetamine

Methamphetamine

Methoxamine

Metaraminol

Think:

"AM makes MANY M's."

⭐ Exam Pearl: Methoxamine and Metaraminol have low drug action.

What happens in the AM pathway?

Methoxamine

Metaraminol

💡 Mnemonic

MM = Mild Medicine

The two M's are less active.

Which drugs have low drug action?

• Ephedrine > Pseudoephedrine > Phenylephrine > Phenylpropanolamine

Mnemonic

PPP

Pseudoephedrine

Phenylephrine

Phenylpropanolamine

Think:

"Three P's in a row."

What happens in the PP pathway?

CADUHT

C = Cough syrup

A = Allergy

D = Decongestant

U = Urinary incontinence

H = Hemostatic (topical)

T = Heart pressor

💡 Mnemonic Sentence

"Cats Always Drink Under Hot Tables."

Phenylpropanolamine has 6 uses.

Mnemonic?

Do NOT take with coffee.

Why?

Both affect the CNS.

💡 Mnemonic

"Coffee + PPA = CNS Overload."

☕

Phenylpropanolamine = 🚫 Too much CNS stimulation

Contraindication of Phenylpropanolamine?

Both pathways originate from Ephedrine, and your notes indicate that these processes may affect the CNS.

💡 High-yield point from your notes:

The notes mention that CNS effects may cause drowsiness.

💡 Mnemonic

"EPH enters the HEAD."

Think:

Ephedrine

↓

CNS effects

↓

Possible drowsiness

Which pathway contains drugs that may affect the CNS?

EPH → AM | PP

AM Branch

AMMM

• Amphetamine

• Methamphetamine

• Methoxamine

• Metaraminol (low drug action)

P Branch

PPP

• Pseudoephedrine

• Phenylephrine

• Phenylpropanolamine

↓

CADUHT

• Cough syrup

• Allergy

• Decongestant

• Urinary incontinence

• Hemostatic

• Heart pressor

↓

❌ No coffee (CNS effects)

Non-catecholamines in one glance.

• 1 Function

• 6 Anti-asthma drugs

• 2 Adverse effects

• 1 Enzyme

• 1 Enzyme inhibitor

β₂ Bronchodilators = 1 • 6 • 2 • 1 • 1

β₂ receptor of the respiratory system

↓

Causes bronchodilation

💡 Mnemonic

β₂ = BREATH

Think:

B₂ → Breathe Better

β₂-selective bronchodilators bind to what receptor?

Bronchodilation

💡 Mnemonic

"Beta TWO opens TWO lungs."

Whenever you see β₂, immediately think:

➡ Bronchi OPEN

Main effect of β₂-selective bronchodilators?

STCPMI

• S = Salbutamol

• T = Terbutaline

• C = Clenbuterol

• P = Pirbuterol

• M = Metaproterenol

• I = Isohaline

💡 Mnemonic Sentence

"Smart Tigers Chase Playful Mighty Iguanas."

There are 6 anti-asthma drugs.

Mnemonic?

Decrease fat in porcine

💡 Mnemonic

SC = Skinny Swine

Salbutamol and Clenbuterol > Skinny pig

Salbutamol and Clenbuterol have what adverse effect in pigs?

Loss of β₂ pulmonary receptor population

💡 Mnemonic

Think:

"Too much knocking, fewer doors."

If β₂ receptors are constantly stimulated, > The lungs remove receptors.

What is the down-regulation effect?

cAMP

💡 Mnemonic

"cAMP carries the message."

Imagine cAMP as a camp messenger delivering the signal from the β₂ receptor.

What serves as the messenger for β-receptor activation?

An intracellular enzyme

↓

Breaks down cAMP

💡 Mnemonic

PDE = "cAMP Destroyer."

Think:

PDE is a pair of scissors ✂Cutting up cAMP.

What is phosphodiesterase?

Inhibits phosphodiesterase

↓

Prevents the breakdown of cAMP

💡 Mnemonic

"A-MINO = Minus PDE."

Aminophylline > PDE inhibited > More cAMP > Better bronchodilation

Aminophylline acts by doing what?

It inhibits phosphodiesterase, preventing cAMP breakdown and enhancing bronchodilation.

💡 Mnemonic

Think of Aminophylline as the bodyguard.

The anti-asthma drug opens the bronchi.

🛡 Aminophylline protects cAMP, so the bronchi stay open longer.

Why is Aminophylline given together with anti-asthma drugs?

1 • 6 • 2 • 1 • 1

1 Enzyme

• Phosphodiesterase

6 Drugs STCPMI

• Salbutamol

• Terbutaline

• Clenbuterol

• Pirbuterol

• Metaproterenol

• Isohaline

2 Adverse Effects SL

• S = Skinny swine (↓ fat in porcine with Salbutamol & Clenbuterol)

• L = Loss of β₂ receptors (down-regulation)

1 Enzyme

• Phosphodiesterase > Breaks down cAMP

1 Inhibitor

Aminophylline > Inhibits phosphodiesterase > More cAMP > Better bronchodilation

β₂-selective bronchodilators in one glance.