MODULE 8 (MODIFIED VER. ORICS)

1. Direct-Acting Parasympathomimetic

2. Naturally occurring Cholinomimetic Alkaloids

under Parasympathetic/Cholinergic, enumerate the types

1. Reversable Inhibitors

2. Irreversible Inhibitors

under Cholinesterase inhibitors, enumerate the types

1. competing for the muscarinic receptor (Atropine and Scopolamine, Synthetic Muscarinic Blocking Drugs)

2. competing for the nicotinic receptor (Nicotine, Synthetic Drugs)

under Parasympatholytic/ANTICHOLINERGIC Drugs, enumerate the types

a. Skeletal Muscle Relaxants.

1. Pre-junctional blockade (biotoxin, electrolytes, antibiotics)

2. Post-junctional blockade (Competitive Non-depolarizing drugs, Competitive Depolarizing drugs)

b. Skeletal Muscle Spasmolytic

1. Centrally acting muscle relaxants

2. Intracellular muscle relaxants

under Neuromuscular Blocking Drugs, enumerate the types

A. Choline Esters → M-B-C
B. Naturally Occurring Cholinomimetic Alkaloids → P-A-M

Think:
“Cholinergic = MBC + PAM

MEMORY ANCHOR

Direct-Acting Parasympathomimetic = 2 groups

3 Drugs → M-B-C
5 Body Actions → C-G-E-R-U
7 Clinical Uses → R-E-T-U-C-I-R

Think:
“MBC acts on CGERU for RETUCIR.”

MEMORY ANCHOR

Choline Esters = 3 • 5 • 7

M-B-C

1. Methacholine

2. Bethanechol

3. Carbachol

💡 Mnemonic:
“My Best Car.”

M = Methacholine
B = Bethanechol
C = Carbachol

Direct-Acting Parasympathomimetic under Choline Esters has what 3 drugs?

Choline / ACh

💡 Mnemonic:
Choline esters = ACh family

ACh = acetylcholine

Choline esters are related to what?

Muscarinic receptor

💡 Mnemonic:
METHA = MUSCA

Methacholine → muscarinic receptor

Methacholine primarily acts on what receptor?

Heart

Less action on muscarinic receptor of:

GI tract
Urinary tract

💡 Mnemonic:
Metha-HEART-line

Methacholine → more active on heart

Methacholine is more active where?

GI tract + urinary tract

💡 Mnemonic:
Metha loves Heart, not Gut/Urine

Heart ↑
GI/Urinary ↓

Methacholine has less action where?

Muscarinic receptor of:

GI tract
Urinary tract

Less active in the muscarinic receptor of the heart.

💡 Mnemonic:
BETHANECHOL = Belly + Bladder

Belly = GI tract
Bladder = urinary tract

Bethanechol is more active where?

Heart

💡 Mnemonic:
Bethanechol = Belly + Bladder, not Beat

Beat = heart

Bethanechol is less active where?

Both nicotinic and muscarinic

Especially in:

GI tract
Urinary tract

💡 Mnemonic:
CARBACHOL = Car has 2 pedals

2 pedals = nicotinic + muscarinic

Carbachol acts on what receptors?

Both nicotinic and muscarinic actions

GI tract
Urinary tract

💡 Mnemonic:
CAR = 2 pedals to Gut + Bladder

Nicotinic + muscarinic
GI + urinary tract

Carbachol is more active on what areas according to the notes?

C-G-E-R-U

1. Cardiovascular system

2. Gastro-intestinal tract

3. Eye

4. Respiratory system

5. Urinary bladder

💡 Mnemonic:
“Choline Gets Eyes Respiratory Urine.”

MEMORY ANCHOR

Choline ester body actions = 5

C-G-E-R-U

1. Cardiovascular system

2. Gastro-intestinal tract

3. Eye

4. Respiratory system

5. Urinary bladder

💡 Mnemonic:
“Choline Gets Eyes Respiratory Urine.”

Choline esters act on what 5 body systems?

Decreases the function of the heart

💡 Mnemonic:
Choline chills the heart

Heart function ↓

Choline esters action on Cardiovascular System?

Contraction → increased peristaltic movement

💡 Mnemonic:
Gut contracts → food moves

GI contraction → peristalsis ↑

Choline esters action on Gastro-Intestinal Tract?

Contraction in the muscle of the eye

💡 Mnemonic:
Eye muscle tightens

Eye → contraction

Choline esters action on Eye?

Constriction

💡 Mnemonic:
Choline constricts breathing tubes

Respiratory → constriction

Choline esters action on Respiratory System?

Contraction

💡 Mnemonic:
Bladder squeezes

Urinary bladder → contraction

Choline esters action on Urinary Bladder?

Carbachol

💡 Mnemonic:
CARBA-horse sweats

Carbachol → profuse sweating in horses

Which choline ester evokes profuse sweating in horses?

R-E-T-U-C-I-R

1. Raynaud’s Disease

2. Ergot Poisoning

3. Tachycardia of supraventricular origin

4. Urinary Bladder Atony in Cats

5. Colic

6. Impaction

7. Rumen atony

💡 Mnemonic:
“Ray Ergot Tachy Urinary Cats Impact Rumen.”

CHOLINE ESTER CLINICAL USES

MEMORY ANCHOR

Clinical uses = 7

R-E-T-U-C-I-R

1. Raynaud’s Disease

2. Ergot Poisoning

3. Tachycardia of supraventricular origin

4. Urinary Bladder Atony in Cats

5. Colic

6. Impaction

7. Rumen atony

💡 Mnemonic:
“Ray Ergot Tachy Urinary Cats Impact Rumen.”

Enumerate the clinical uses of Choline Esters. Mnemonic?

Methacholine

💡 Mnemonic:
Raynaud’s needs Metha

Raynaud’s Disease → DOC: Methacholine

DOC for Raynaud’s Disease?

Any of the 3 choline esters

Methacholine
Bethanechol
Carbachol

💡 Mnemonic:
Ergot poisoning? Use M-B-C.

Any of the 3

Treatment for Ergot Poisoning?

Supraventricular origin

💡 Mnemonic:
Tachy above the ventricles

Supra = above
Ventricular = ventricles

Choline esters are used for tachycardia of what origin?

Bethanechol

💡 Mnemonic:
Bethanechol = Bladder + Cat

B = Bladder
Cat = urinary bladder atony in cats

DOC for Urinary Bladder Atony in Cats?

Bethanechol

💡 Mnemonic:
BETHA-BELLY

Bethanechol → belly/GI → colic

DOC for Colic?

Carbachol

💡 Mnemonic:
CARBA-clears the clog

Impaction → DOC: Carbachol

DOC for Impaction?

Carbachol

💡 Mnemonic:
Carbachol starts the cow car engine

Rumen atony → DOC: Carbachol

DOC for Rumen Atony?

U-C

1. Urinary Bladder Atony in Cats

2. Colic

💡 Mnemonic:
Bethanechol = Bladder + Belly

Bladder atony in cats
Colic

Which choline ester DOCs are Bethanechol?

I-R

1. Impaction

2. Rumen atony

💡 Mnemonic:
CARBA-clears Impacted Rumen

Impaction
Rumen atony

Which choline ester DOCs are Carbachol?

Raynaud’s Disease

💡 Mnemonic:
Metha meets Ray

Methacholine → Raynaud’s Disease

Which choline ester DOC is Methacholine?

3 Drugs → P-A-M
7 Body Actions → C-G-E-R-U-S-S
3 Clinical/Contra Uses → G-S-T

Think:
“PAM acts on CGERUSS for GST.”

NATURALLY OCCURRING CHOLINOMIMETIC ALKALOIDS MEMORY ANCHOR

Naturally Occurring Cholinomimetic Alkaloids = 3 • 7 • 3

P-A-M

1. Pilocarpine

2. Arecoline

3. Muscarine

💡 Mnemonic:
“PAM is natural.”

P = Pilocarpine
A = Arecoline
M = Muscarine

Enumerate the 3 Naturally Occurring Cholinomimetic Alkaloids. Mnemonic?

Pilocarpus jaborandi
P. microphyllus

💡 Mnemonic:
PILO from PILO-carpus

Pilocarpine → Pilocarpus

Pilocarpine comes from what plant?

Areca catechu

Also known as:

Betel nut / nga-nga

💡 Mnemonic:
ARECOLINE from ARECA

Areca catechu → Betel nut / nga-nga

Arecoline comes from what plant?

Poisonous mushroom Amanita muscaria

💡 Mnemonic:
MUSCARINE from MUSCARIA

Muscarine → Amanita muscaria

Muscarine comes from what source?

C-G-E-R-U-S-S

1. Cardiovascular system

2. Gastro-intestinal tract

3. Eye

4. Respiratory system

5. Urinary bladder

6. Skeletal muscle

7. Sweat gland

💡 Mnemonic:
“Choline Gets Eyes Respiratory Urine, Skeletal Sweat.”

NATURAL CHOLINOMIMETIC ACTIONS

MEMORY ANCHOR

Natural cholinomimetic actions = 7

C-G-E-R-U-S-S

1. Cardiovascular system

2. Gastro-intestinal tract

3. Eye

4. Respiratory system

5. Urinary bladder

6. Skeletal muscle

7. Sweat gland

💡 Mnemonic:
“Choline Gets Eyes Respiratory Urine, Skeletal Sweat.”

Naturally occurring cholinomimetic alkaloids act on what 7 body systems?

Decreases the function of the heart

💡 Mnemonic:
Natural choline chills the heart

Heart function ↓

Natural cholinomimetics action on Cardiovascular System?

Contraction → increased peristaltic movement

💡 Mnemonic:
Gut contracts → peristalsis increases

Natural cholinomimetics action on Gastro-Intestinal Tract?

Contraction in the muscle of the eye

💡 Mnemonic:
Eye muscle contracts

Natural cholinomimetics action on Eye?

Constriction

💡 Mnemonic:
Respiratory tubes constrict

Natural cholinomimetics action on Respiratory System?

Contraction

💡 Mnemonic:
Bladder squeezes

Natural cholinomimetics action on Urinary Bladder?

Contraction

💡 Mnemonic:
Skeleton squeezes

Skeletal muscle → contraction

Natural cholinomimetics action on Skeletal Muscle?

Sweat gland

💡 Mnemonic:
S = Sweat

Natural cholinomimetics → sweat gland

Natural cholinomimetics act on what gland?

Pilocarpine

💡 Mnemonic:
PILO opens eye flow

Glaucoma → DOC: Pilocarpine

NATURAL CHOLINOMIMETIC CLINICAL USES

DOC for Glaucoma?

Pilocarpine

💡 Mnemonic:
PILO pulls apart Synechia

Synechia → DOC: Pilocarpine

DOC for Synechia?

G-S

1. Glaucoma

2. Synechia

💡 Mnemonic:
PILO protects the eye: Glaucoma + Synechia

Pilocarpine is DOC for what 2 conditions?

Iridocyclitis

Inflammation of:

Iris
Ciliary body

Pilocarpine should not be used.

💡 Mnemonic:
PILO? NO if Iris is Inflamed

Contraindication of Pilocarpine?

Iris + ciliary body

💡 Mnemonic:
IRIDO = iris
CYCLITIS = ciliary body inflammation

Iridocyclitis is inflammation of what?

Arecoline

💡 Mnemonic:
ARECOLINE attacks tapeWORM

Arecoline → taeniacide / tapeworm

DOC for Taeniacide / tapeworm?

Parasympathetic / Cholinergic

MASTER MEMORY MAP

Drugs acting on Autonomic Nervous System

Methacholine

Bethanechol

Carbachol

MASTER MEMORY MAP

A. Direct-Acting Parasympathomimetic

Choline Esters = M-B-C

Cardiovascular → decreases heart function
GI tract → contraction → peristaltic movement ↑
Eye → contraction in eye muscle
Respiratory → constriction
Urinary bladder → contraction

MEMORY MAP

Choline Ester Actions = C-G-E-R-U

Raynaud’s Disease → DOC: Methacholine
Ergot Poisoning → any of the 3 drugs
Tachycardia of supraventricular origin
Urinary Bladder Atony in Cats → DOC: Bethanechol
Colic → DOC: Bethanechol
Impaction → DOC: Carbachol
Rumen atony → DOC: Carbachol

Clinical Uses = R-E-T-U-C-I-R

Pilocarpine
→ from Pilocarpus jaborandi, P. microphyllus
→ DOC: glaucoma + synechia
→ contraindication: iridocyclitis

Arecoline
→ from Areca catechu
→ betel nut / nga-nga
→ DOC: taeniacide / tapeworm

Muscarine
→ from poisonous mushroom Amanita muscaria

Actions = C-G-E-R-U-S-S

Cardiovascular → decreases heart function
GI tract → contraction → peristaltic movement ↑
Eye → contraction in eye muscle
Respiratory → constriction
Urinary bladder → contraction
Skeletal muscle → contraction
Sweat gland

Naturally Occurring Cholinomimetic Alkaloids

Drugs = P-A-M

1 Natural drug → Physostigmine
4 Synthetic drugs → N-E-P-A
7 Body actions → C-G-E-R-U-S-S
4 Clinical uses → G-S-I-M

Think:
“PHYSO has NEPA, acts on CGERUSS, treats GSIM.”

MEMORY ANCHOR

Cholinesterase Inhibitors → Reversible Inhibitors = 1 • 4 • 7 • 4

They bind temporarily to the cholinesterase enzyme.

💡 Mnemonic:
Reversible = returns / releases

Temporary binding → reversible inhibition

What do reversible cholinesterase inhibitors do?

Cholinesterase enzyme

💡 Mnemonic:
Choline-esterase = enzyme that handles choline signals

Reversible inhibitor → temporarily binds cholinesterase

Reversible cholinesterase inhibitors bind temporarily to what enzyme?

Physostigmine

💡 Mnemonic:
PHYSO = physical / natural source

Physostigmine → main drug listed

Main natural drug under reversible cholinesterase inhibitors?

Physostigmine venenose

Also called:
Calabar of ordeal bean

💡 Mnemonic:
PHYSO from PHYSO plant

Physostigmine → Physostigmine venenose

Physostigmine comes from what plant?

Calabar of ordeal bean

💡 Mnemonic:
PHYSO took the ordeal bean test

Calabar of ordeal bean → Physostigmine source

What is the plant source nickname of Physostigmine?

N-E-P-A

1. Neostigmine

2. Edrophonium

3. Pyridostigmine

4. Ambenomium

💡 Mnemonic:
“NEPA blocks cholinesterase.”

N → Neostigmine
E → Edrophonium
P → Pyridostigmine
A → Ambenomium

SYNTHETICS

Enumerate the synthetic reversible cholinesterase inhibitors. Mnemonic?

N → Neostigmine
E → Edrophonium
P → Pyridostigmine
A → Ambenomium

💡 Mnemonic:
“NEPA = synthetic squad.”

What does N-E-P-A stand for?

Neostigmine

💡 Mnemonic:
NEO = new synthetic

Which synthetic reversible inhibitor starts with N?

Edrophonium

💡 Mnemonic:
E = Edrophonium

Which synthetic reversible inhibitor starts with E?

Pyridostigmine

💡 Mnemonic:
PYRIDO = P

Which synthetic reversible inhibitor starts with P?

Ambenomium

💡 Mnemonic:
AMBEN = A

Which synthetic reversible inhibitor starts with A?

C-G-E-R-U-S-S

1. Cardiovascular system

2. Gastro-intestinal tract

3. Eye

4. Respiratory system

5. Urinary bladder

6. Skeletal muscle

7. Sweat gland

💡 Mnemonic:
“Choline Gets Eyes Respiratory Urine, Skeleton Sweats.”

BODY ACTIONS MEMORY ANCHOR

Reversible cholinesterase inhibitor actions = 7

C-G-E-R-U-S-S

1. Cardiovascular system

2. Gastro-intestinal tract

3. Eye

4. Respiratory system

5. Urinary bladder

6. Skeletal muscle

7. Sweat gland

💡 Mnemonic:
“Choline Gets Eyes Respiratory Urine, Skeleton Sweats.”

Reversible cholinesterase inhibitors act on what 7 body systems?

Decreases the function of the heart

💡 Mnemonic:
Choline chills the heart

Heart function ↓

Action of reversible cholinesterase inhibitors on the cardiovascular system?

Contraction → increased peristaltic movement

💡 Mnemonic:
GI contracts → peristalsis goes

Action of reversible cholinesterase inhibitors on the GI tract?

Contraction in the muscle of the eye

💡 Mnemonic:
Eye muscle contracts

Action of reversible cholinesterase inhibitors on the eye?

Constriction

💡 Mnemonic:
Respiratory tubes constrict

Action of reversible cholinesterase inhibitors on the respiratory system?

Contraction

💡 Mnemonic:
Bladder squeezes

Action of reversible cholinesterase inhibitors on the urinary bladder?

Contraction

💡 Mnemonic:
Skeleton squeezes

Action of reversible cholinesterase inhibitors on skeletal muscle?

Sweat in horse

💡 Mnemonic:
Horse sweats from choline effect

Sweat gland → sweat in horse

Action of reversible cholinesterase inhibitors on sweat gland?

G-S-I-M

1. Glaucoma

2. Synechia

3. Impaction

4. Myasthenia gravis / Grandmal in dogs

💡 Mnemonic:
“Good Students Improve Muscles.”

G → Glaucoma
S → Synechia
I → Impaction
M → Myasthenia gravis / Grandmal in dogs

CLINICAL USES

MEMORY ANCHOR

Clinical uses = 4

G-S-I-M

1. Glaucoma

2. Synechia

3. Impaction

4. Myasthenia gravis / Grandmal in dogs

💡 Mnemonic:
“Good Students Improve Muscles.”

Enumerate the clinical uses of reversible cholinesterase inhibitors. Mnemonic?

Physostigmine

💡 Mnemonic:
PHYSO fixes eye pressure

Glaucoma → DOC: Physostigmine

DOC for Glaucoma under reversible cholinesterase inhibitors?

Physostigmine

💡 Mnemonic:
PHYSO separates Synechia

Synechia → DOC: Physostigmine

DOC for Synechia under reversible cholinesterase inhibitors?

Physostigmine

💡 Mnemonic:
PHYSO pushes impaction

Impaction → DOC: Physostigmine

DOC for Impaction under reversible cholinesterase inhibitors?

G-S-I

1. Glaucoma

2. Synechia

3. Impaction

💡 Mnemonic:
PHYSO = GSI

Think:
“Physostigmine Goes Straight In.”

G → Glaucoma
S → Synechia
I → Impaction

Physostigmine is DOC for what 3 clinical uses?

Neostigmine

💡 Mnemonic:
NEO = nerve-muscle helper

Myasthenia gravis / Grandmal in dogs → DOC: Neostigmine

DOC for Myasthenia gravis / Grandmal in dogs?

Myasthenia gravis / Grandmal in dogs

💡 Mnemonic:
NEO helps weak muscles

Myasthenia gravis → muscle weakness clue

Neostigmine is DOC for what condition in dogs?

→ A. Reversible Inhibitors
→ bind temporarily to cholinesterase enzyme

MASTER MEMORY MAP

Cholinesterase Inhibitors

→ from Physostigmine venenose
→ Calabar of ordeal bean

MEMORTY MAP

Main drug:
Physostigmine

Neostigmine
Edrophonium
Pyridostigmine
Ambenomium

MEMORY MAP

Synthetics = N-E-P-A

Cardiovascular → decreases heart function
GI tract → contraction → peristaltic movement ↑
Eye → contraction in eye muscle
Respiratory → constriction
Urinary bladder → contraction
Skeletal muscle → contraction
Sweat gland → sweat in horse

MEMORY MAP

Actions = C-G-E-R-U-S-S

Glaucoma → DOC: Physostigmine
Synechia → DOC: Physostigmine
Impaction → DOC: Physostigmine
Myasthenia gravis / Grandmal in dogs → DOC: Neostigmine

MEMORY MAP

Clinical Uses = G-S-I-M

5 OP Compounds → M-P-R-C-DTH
2 Clinical Uses → A-P
5 Poisoning Signs → V-S-D-S-B
2 Antidote/Treatment Drugs → A-P

Think:
“OP = 5 drugs, 2 uses, 5 signs, 2 treatments.”

MEMORY ANCHOR

Irreversible Cholinesterase Inhibitors = 5 • 2 • 5 • 2

Permanently

Binding with the enzyme is irreversible.

💡 Mnemonic:
Irreversible = it cannot reverse

Temporary = reversible
Permanent = irreversible

Irreversible cholinesterase inhibitors bind to the enzyme how?

Organo Phosphorus Compounds

Also written as:

OP Compounds

💡 Mnemonic:
OP = Organophosphorus

Irreversible inhibitors are also called what compounds?

M-P-R-C-DTH

1. Malathion

2. Parathion

3. Ronnel

4. Co-ral

5. Dichlorvos / Trichlorphon / Haloxon

💡 Mnemonic:
“Mali Para Ron Cor DTH.”

Or easier:

“Mali Para, Ron Cor, DTH.”

OP COMPOUNDS / DRUGS

MEMORY ANCHOR

OP Compounds = 5 groups

M-P-R-C-DTH

1. Malathion

2. Parathion

3. Ronnel

4. Co-ral

5. Dichlorvos, Trichlorphon, Haloxon

💡 Mnemonic:
“Mali Para, Ron Cor, DTH.”

Enumerate the OP compounds under irreversible inhibitors. Mnemonic?

M → Malathion
P → Parathion
R → Ronnel
C → Co-ral
D → Dichlorvos
T → Trichlorphon
H → Haloxon

💡 Mnemonic:
“Mali Para, Ron Cor, DTH.”

What does M-P-R-C-DTH stand for?