Okay. Antiarrhythmics drugs seem complicated in the beginning but hopefully they would get better by studying some diagrams and drawing them. Lippincott pharm book has many good pictures. I'm not sure about pharm recall.
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It is my personal opinion that it will be the to memorize those drugs by categories. What I mean is that all of class IA drugs have a same mechanism, IB drugs same and IC drugs same. So, as long as we know which drugs belong to which category, we can easily know what each does.
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With Sanjai's recommendation, (thanks to Sanjai!) I listened to Doctors in Training. These audio files are too big to send out via email but they are all over the places in internet. I got the 2010 audio version.
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DIT said some good mneumics to start. I think I sent out about this menumonics while ago but here it is! I also like the FIRST AID mneumonics on pg.280 because their mneumonics contain more similar words/rhyms to actual names of the drugs while DIT's mneumonics only uses first letters of each drug. Sometimes, remembering the mneumonics is more difficult than remembering the actual contents. lol.
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No // Bad boy // Keeps // Clean

NO
[Na+] channel blockers. Class I
BAD BOY
B-blockers. Class II
KEEPS
[K+] channel blockers. Class III.
CLEAN
[Ca+2] channel blockers. Class IV.
.

Police Department Questions // The Little Man // For Pushing Ecstasy.

Police Department Questions
Procainamide, Disopyramide, Quinidine. Class IA (*Not commonly used)
The LIttle Man
Tocainide, Lidocaine, Mexiletine. Class IB (*Most commonly used)
For Pushing Ecstasy
Flecainide, Encainide, Propafenone. Class IC.
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In continuation from Sanjai's awesome IA drugs mneumonics...here is class IB drugs that I noted from the Kaplan lecture.
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Class IB ;
It blocks
1) Fast [Na+] channels
2) Inactivated [Na+] channels (M gate opened and h gate closed), therefore, preventing it from going back to the resting state (M gate closed and h gate opened). This mechanism is specific to hypoxic and ischemic heart as it keeps those cells in the hypoxic tissues to enter refractory --> Slowing the conduction.
3) Slow [Na+] window current --> decreased action potential duration. **I didn't know this before that slow [Na+] channel opens during plateau phase to keep integrity of the membrane while K+ and Ca2+ are passing out/in. --> ultimately, this would allow shorten action potential so that there is more time for diastole/filling

Lidocaine.
Usage;
1. The same drug that you would use for anesthetics. Used for Post-MI, Open-heart surgery and Digoxin toxicity (or digitalis-induced arrhythmias).
2. Digoxin toxicity was very emphasized in both of Kaplan and DIT. (but i still struggle to get the big concept..) What I understood is that digoxin or positive inotropy can cause tachyrhythmia when it is given too much. As an antidote (FIRST AID p.279), you would give Lidocaine.

Side-effects;

1. First pass metabolism digests this drug so only used via IV --> cannot send patients home with this drug --> if necessary, use Mexiletine or Tocainide (oral) instead.

2. CNS toxicity or seizure. However it has the least cardiotoxicity among conventional anti-arrhythmics.

Mexiletine and Tocainide
Same as Lidocaine, however they are available as oral formulations.
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Sept 28th, 2010

For cardio, let's go in the order of Kaplan, but refer to First Aid for what's most relevant.
ie) since Kaplan starts with Antiarrhythmic drugs, we'll start creating mnemonics for those even though these drugs are toward the end of First Aid.

Na Channel Blockers: Class 1A
Quinidine, Procainamide, disopyramide
- all increase action potential duration and effective refractory period

mn
- First Aid has a good one
- the Queen Proclaims Diso's pyramid


Toxicities
Quinidine
- M blocker and alpha blocking effects (as you can see, it's really important to have a solid foundation of basic pharm from earlier units!).
- Just think of a Queen dictator blocking any competition to the throne.

Procainamide
- Lupus- like syndrome
- I think of ProKane (the professional wrestler Kane). He wears a mask to cover the typical malar rash of the face and if you watch him move, he moves like he has arthritis and joint pain. Just google Kane and think of him (note: he's apparently become unmasked in recent years, but just ignore that...it was news to me!)

Reminder: meeting at noon Tues Sept 28th at Fake Aroma

I'm going to throw out the drug names and we'll see if we can figure out what they do by remembering the mnemonics from here or ones that you created on your own.

I created some new mnemonics as well which might help the drugs stick better. I think we're all starting to get the hang of pharmonics!!!

Sept 25, 2010 - Cytochrome P450

Just a small detour because this is really important. Certain drugs either induce or inhibit P-450 proteins of the liver. We need to have a general idea of the major ones that do this. I basically used First Aid and Kaplan and added the drugs together. I mostly used First Aid mnemonics and adjusted them slightly.

INDUCERS:

Quinidine

Barbiturates

St.John's Wart

Phenytoin

Rifampin

Griseofulvin

Carbamazepine

Chronic alcohol

Glucocorticoids

Queen Barb Steals Phen-Phen and Refuses Greasy Carbs, Chronic Alcohol, and Glucose.

(Queen Barb is really fat so she takes Phen-Phen and she refuses all the other things so she can get skinny) - Phen-Phen was a weight loss drug in the past

*Quinidine can be both an inducer or an inhibitor depending on the person's P-450 isoform. It is more commonly an inducer.

INHIBITORS:

Acute alcohol

Ketoconazole

Erythromycin (& other macrolides)

Grapefruit juice

Sulfonamides

Isoniazid

Cimetidine

Chloramphenicol

Omeprazol

Inhibit yourself from drinking Alcohol from a KEG. It will make you a SICCO!

1) Drug: Clonidine

Use:
Hypertension, especially with renal disease

Mechanism:
Clonidine is a centrally-acting α-adrenergic receptor agonist with more affinity for α2 than α1. Stimulates α2 receptors in the brain, which decreases cardiac output and peripheral vascular resistance, lowering blood pressure. It has specificity towards the presynaptic α2 receptors in the vasomotor center in the brainstem. This binding decreases presynaptic calcium levels, and inhibits the release of norepinephrine (NE). The net effect is a decrease in sympathetic tone.

Side Effects:
Short half-life. Sudden discontinuation can cause rebound hypertension. Sedation. Dizziness. Dry-mouth. As mentioned before, Clonidine is a centrally-acting α-adrenergic receptor agonist with more affinity for α2 than α1. Therefore if overdose, it actually can causes hypertension. These effects are seen during an overdose in children, where after taking clonidine their blood pressure increases. As the clonidine is eliminated by the body the peripheral effects wear off and the central hypotensive effects become visible. Both the hypertensive and hypotensive effects can be harmful.

Mnemonic:
"Cl" looks like α. And there are two "i"s in Clonidine. Clonidine is clonning α2. Therefore, it is α2 agonist.


2) Drug: α-Methyldopa
Almost same as Clonidine.

Use:
Hypertension, especially with renal disease

Mechanism:
Stimulates central pre-synaptic α2-adrenergic receptors, and inhibits the release of norepinephrine. -> Decreased peripheral vascular resistance and reduction in cardiac output.
***α-Methyldopa is considered to be safe to use pregnancy for hypertensive blood pressure medication.

Side Effects:
Hemolytic anemia. Hepatitis. Edema. Sedation. Impotence. Dizziness. Dry-mouth.

Mnemonic:
α-Methyldopa starts with α and ends with a. Therefore two α or α2. As you know epi/norepinephrine are derived from DOPA (Tyrosine -> DOPA -> Dopamine -> Norepinephrine -> Epinephrine). If you compare at the molecular structures of α-Methyldopa and DOPA, methyldopa has an extra methyl (CH3) group added to DOPA at carbon #2. Since α-Methyldopa is so similar to DOPA, it will replace DOPA, which now canNOT be made to further derivates of dopamine, norepi and epi due to the presence of extra methyl group.

So it wants to be agonist but blocking out norepi sympathetic effect.
α-Methyldopa = α2 agonist.

Sept 23rd, 2010

Here are Lindsey's from Thursday! Look at her attachment for her picture.

Thursday September 23, 2010

(1)  Dobutamine = B1 agonist (minor B2 and α1 agonist)

Inotropic (↑SV and ↑ contractility) but not chronotropic (does not ↑ HR)

Used to treat heart failure by ↑CO

**since it does not activate D receptors (which release norepinephrine) Dobutamine is is less prone to induce hypertension

Mnemonic:  Dobutamine sounds like Dopamine.  So when you see a patient with Cardiac Failure think of using Dopamine BUT without the bad D receptor effects.  

(2) Phenylephrine = α1 agonist (minor  α2 agonist)

Used clinically:

nasal decongestant (nasal spray or PO)

pupil dilation (for eye exams)

Vasoconstrictor 

To ↑ BP for pts with hyp0tension

To abort priapsism (nonsexual erection)

Side effects = Hypertension

This mnemonic is very much like a MMRS

First of all you see the word EPHRINE in the word so you know that the drug has “epinephrine-like” properties.

Now look at the picture below:

This man who has phenyl groups for eyes has an unwanted erection and a runny nose.  He is so embarrassed that he is hypOtensive.

After you prescribe Phenylephrine, he feels so much better that his eyes brighten (mydriasis)

Sept 21st, 2010

Pretty hard to get these words down since the vacation has just started! But I managed to muster the energy somehow : P


Hexamethonium
- not used clinically, but important in research

Clinical applications
- none
- but some ganglionic blockers can be used for severe hypertension

Action
- nicotinic receptor antagonist and since nicotinic receptors are widespread throughout the body, you will see many effects.
- most important is that they block the baroreceptor response by blocking the receptor at the ganglia where preganglionic and postganglionic neurons meet.
ex) alpha 1 vasoconstriction increases BP. Blocking the baroreceptor reflex will prevent reflex bradycardia.

Side Effects
- since it blocks at so many sites, there will be many potential adverse effects.
- look at First Aid. Key is that ganglionic blockers will mainly block dominant system at the organ.
ie) in the heart: mainly PANS blocked causing tachycardia as potential adverse effect

mn
- Hex = spell. So I just think of a witch casting a spell on someone. Spells don't affect one organ, they affect the entire person. So you'll see all sorts of side effects. A witch wants to weaken you, so all dominant innervation will be affected at each organ.


Epinephrine & Norepinephrine
- no need for mnemonics here since we'll see these everywhere!
- just keep in mind that Epi is a hormone secreted from the adrenal gland and has affinity to B2 receptors, whereas, NorEpi does not bind to B2 and acts mainly as a neurotransmitter.


Isoproterenol

Mechanism/Selectivity
- B1 & B2 affinity

Clinically
1) B1 stimulation for heart block/arrythmias to increase HR
2) B2 stimulation used to be used for bronchodilation in asthmatics

mn
- here, you have to keep in mind its dual action.
- I think of : IsAproRenal ... ppl who have good renal function (Pros), have 2 kidneys and kidneys are bean shaped (like B receptors)

Methscopolamine (oxybutynin, glycopyrrolate)

mech--parasynpathetic muscarinic (Ach) antagonist

tx--genitourinary cystitis, bladder spasms, decrease urgency to pee.

mnemoic: scopolamine is to treat motion sickness, think of adding a ch3 (meth) group would make you less wanting to pee. Story time: you are on the airplane, you had to pee, but there was turbulence on your walk to the toilet, by the time you get there, you don't want to pee anymore, but just are dizzy.

Pirenzepine (propantheline)

mech-parasynpathetic muscarinic (Ach) antagonist

tx--peptic ulcer

mnemoics: when you have a "piercing "(piren) pain from the ulcer in your stomach, pirenzepine can "zap" it.

Sept 17, 2010

1) Drug: Scopolamine

Use: prophylaxis or treatment of motion sickness

Mech: Muscarinic blocker

Side Effect: nothing special

Mnemonic: I just think of looking through a 'teleSCOPE' while driving and getting really dizzy!

2) Drug: Ipratropium

Use: asthma or COPD

Mech: Muscarinic blocker - bronchodilates and inhibits bronchus secretions

Side Effect: nothing special

Mnemonic: First aid has a good one- 'I PRAY I can breathe again'

(1) Echothiophate= acytlcholinesterase inhibitor

Usage= treat Glaucoma

Adverse effects = muscle spasms and other systemic effects

Mnemonic:

A man suffering from Glaucoma is relying on hearing an ECHO to determine the distance of objects near him (basically “seeing” like a bat). His doctor prescribes him Echothiophate to treat his glaucoma. Now, he can see but his THIGH (thi) has a tendency to spaz. He is so happy he can see that he responds to this symptom by saying “Oh (o), I guess it’s my FATE (phate)”.

(2) sort of skipping this one because I’m sure we all know this important drug: Atropine (belladonna).

Reminder:

Atropine = competitive antagonist for the muscarinic acetylcholine receptor.

Atropine basically blocks the parasympathetic system. Therefore all of its effects/usage are basically anti-parasympathetic – or pseudo-sympathetic effects.

I can't think of any mnemonics for it. But there are a bunch of drugs that are derivatives of this and so have atropine (trop, opine, or pine) in the name. - So just look out for that

Examples:

* Homatropine (I went HOMe to take Atropine)

* tropamide (TROP from atropine with an amide attached)

(3) Benztropine

Here's another example - right half of the word TROPINE = atropine!!

First Aid's mnemonic is great!

Benztropine is used to treat Parkinson's disease. --> go PARK my Mercedes BENZ

Edrophonium

mech: increast Ach by blocking cholinesterase

usage: short acting to diagnose Myasthenia Gravis ( Antibody blocks Ach receptor)

mnemonic: all it takes is a DROP to know if you have got MG


Physostigmine

mech: increase Ach by blocking cholinesterase

usage: glaucoma (cx BBB to CNS) and atropine (pupil dilation) counteraction

mnemoic: it STIGs your eyes (PHYS)

Methacholine
-choline refers cholinomimetic agent (stuffs that act like acetylcholine that activates parasympathetic responses).

Meth- ; think of it as the addictive meth drug.

Minsoo thought meth was some sniffing sugar, so he tries to stiff it in. However, it turned out to be meth! So he coughs very bad.

Explanation;

Methacholine causes bronchoconstriction which is used for diagnostic purposes of asthma.

Neostigmine, Pyridostigmine
-stigmine; think of it as STIG MISSILE that destroys acetylcholinesterase. However, STIG MISSILE has some program errors so that it can only reversibly destroys acetylcholinesterase.

Neostigmine stimulates BenG because BenG likes to watch fireworks of STIG MISSILE destroying acetylcholinesterase. But BenG watches it too close and now screams NEEOOO! and runs strangely because he doesn’t want to get fireworks falling on top of his head and get damaged on his CNS. But Minsoo already saw some fireworks are about to fall on his head so the pilot Minsoo throws some mint pies at him to protect his head. Fortunately, BenG ‘s head is safe! Woo hoo!

Explanation;

Neostigmine stimulates the bladder and GI tract (BenG). It does not enter CNS. And it is used in treatment of myasthenia gravis, an autoimmune disease caused by antibodies to the nicotinic receptor at neuromuscular junctions. Its popular symptoms are weakness of eyes and limb muscles in which people walk strangely.

Pyridostigmine is another cholinesterase inhibitor that is used in the chronic management of myasthenia gravis. It also does not penetrate CNS.

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Minsoo

Sept 14, 2010- Methacholine

1) Drug: Methacholine

Use: challenge test for asthma. As a Muscarinic agonist, it will cause bronchoconstriction. However, those with asthma, since their airways are very sensitive, bronchoconstriction occurs at a much lower dose.

Mechanism: Muscarinic agonist. With 'chol', always think of Ach

Side effects: nothing special. Same side effects as with any Muscarinic agonist

Mnemonic: 'chol' gives you the mechanism of action.

The most important thing here is to link 'methacholine' to asthma. I just think of 'meta-coal'. Meta-coal is a type of coal. It's usually called 'meta-anthracite'. I just think of smoking some 'meta-coal' which would be really bad for your lungs!

- you can also think of it as 'metal coal'. Smoking a mix of 'metal-coal' would be pretty bad for the lungs!

2) Drug: Edrophonium

Use: diagnosis of Myasthenia Gravis

- it's use will make a cholinergic crisis worse but it will improve Myasthenia Gravis. That way, if you give it to a patient with muscle weakness and edrophonium improves it, then the patient has Myasthenia Gravis.

Mechanism: inactivates AchE (reversibly) thereby increasing Ach

Side effect: nothing special

Mnemonic: I just think of diplomacy which can prevent war. Diplomacy 'On the phone' (leaders talking on the phone) prevents 'graves' .

I want to point out that Edrophonium doesn't TREAT graves, it DIAGNOSES it.

Sept 12th, 2010

1) Bethanechol
- clinically: used for ileus and urinary retention
- action: activates smooth muscle in Bowel to push feces out, and destrusor muscle of Bladder to push urine out.

mnemonic
- bethanechol = BeThinAndCall
 Think of a horse jockey. They are notorious for losing weight (ie. using diuretics). So, they would be taking BeThinAndCall.
When you want to lose weight, you want to lose as much urine and feces as possible.

Think of a horse jockey in a race. He's desperate to win, so he starts taking BeThinAndCall, thus urinating and excreting to lose weight and Become Thin. He Calls out as he charges past other contenders.

Or, an alternative: think of a horse jockey in the toilet taking BeThinAndCall before a big race, eliminating his feces and urine, thus Becoming Thin. While he urinates or excretes, he is calling
(ie. the noises you make when you go to the washroom)


2) Carbachol
- clinically: glaucoma
- action: decreasing intraocular pressure

mnemonic
- Carbachol = CarbsAndAlcohol
- think of Carbs in Alcohol (ie. slice of pizza in a bottle of beer). That's got to give you a killer sleep! If you've noticed, when you take a nap or feel tired, your eyes get really watery. Watery eyes = decreasing fluid from eyes, thus decreasing ocular pressure.


3) Pilocarpine
- clinically: glaucoma
- action: decrease intraocular pressure (by contraction of ciliary muscle and circular muscle of iris)

mnemonic
- Pilocarpine = PillowOfCarps
Imagine you are sleeping on a Pillow of Carps (type of big fish). Again, when you're sleeping, your eyes get watery. Watery eyes = decreasing fluid from eyes, thus decreasing ocular pressure.

Or think of the hungry carps desperate for some water. They are suffocating in the pillow and suck at your eyes to get at the liquid for their gills.

Brain and CNS disturbances are common side effects. You are sleeping on a PillowOfCarps...can't be too comfortable for your head, thus it affects your brain.