Dopamine and Serotonin

I prefer to study material in table format becaue I can easily find what I want and it provides a condensed version of the same material in text. I often create tables like the ones below and use them instead of material in First Aid or Kaplan. These 2 tables are for Dopamine and Serotonin Pharmacology. I will post more tables and notes like these soon.

Final Thoughts on Pharmacology

I'm finally done with Pharm! I'm very ecstatic, this was one of my worst subjects in school but I've come to enjoy it over the past few days.
My plan for Pharm was to use Kaplan and then go through first aid. That's exactly what I did at the beginning, but it was too time consuming. When I started going through first aid, I realized that everything I needed to know was in first aid! I realized that I wouldn't have time to go through Kaplan again before the exam, so I decided to annotate in First Aid anything that was written in Kaplan but not first aid (sometimes making page references if there was a diagram or a whole page that I didn't want to copy into first aid). I think this will save me so much time when it comes time to do my final reading. Having one source to study from is much more pragmatic than reading the same material from 2 different books.

The moral of the story: Don't underestimate First Aid!

Near the end of the Pharmacology section in First Aid, there's a 2 page list of the most important side effects and their drug associations. These 2 pages are PURE GOLD! I'd say that these 2 pages are the 2 most important pages in Pharm.
Now that I'm done with my first read for all subjects, I'm going to be starting my 2nd read, during which I plan on annotating everything from Kaplan into First Aid. This way, during the final week, I can go through first aid and now have to worry about going through all the kaplan books again. I'm scheduled to take the exam in late July, and I still have a lot to do!

Serotonin Syndrome and Hypertensive Crisis

Two highly tested drug interactions for CNS drugs are Serotonin syndrome and Hypertensive crisis.

The purpose of this diagram is to present these interactions in an "easily digestible" manner.

SSRI Can cause Serotonin syndrome
MAOI can cause Serotonin Syndrome
MAOI can cause Hypertensive Crisis

*Note that TCAs can cause all 3 of the above interactions.

The drug at the beginning of the arrow can cause the result at the end of the arrow with any 1 of the drugs above or below the arrow.

Print this diagram and stick it into the Pshchiatry-Pharmacology Section of First Aid.

Once Again

Conflict:

Kaplan says: Local anesthetics bind preferentially to activated Na channels.

First aid says: Local anesthetics bind preferentially to INactivated Na channels.

So who's right? Once again, both are correct! According to Katzung Basic and Clinical Pharmacology (LANGE), local anesthetics have an increased affinity for BOTH activated and inactivated states of Na channels, but they have a low affinity for resting Na channels. Remember that Na channels in the heart and neurons have 3 states according to their M and h gates (resting, activated, and inactivated). Neurons with higher rates of firing have more Na channels in the activated and inactivated states, and less in the resting/ready state.

Mannitol (First Aid VS Kaplan)

Conflict:

Kaplan says: Mannitol is used in anuric states

First Aid says: Mannitol is contraindicated in anuria
 
Which is right? They're both right. Huh? It depends on the cause of anuria. Here is what the ultimate encyclopedia of medicine (wikipedia) says:
 
"Mannitol is a medicine that is used to increase the amount of water removed from the blood and thus improve the blood flow to the kidneys. However, mannitol is contraindicated in anuria secondary to renal disease, severe dehydration, intracranial bleeding (unless during craniotomy), severe pulmonary congestion, or pulmonary edema."
http://en.wikipedia.org/wiki/Anuria

Antiarrhythmics

Each antiarrhythmic drug has a predominant use for certain types of arrhythmias. You need to be able to determine which antiarrhythmic is suitable for certain arrhythmias. Yes, this is more important for Step 2, however it is knowledge you are required to have some familiarity with for Step 1, especially since often the stem of the question may reveal the type of arrhythmia and ask you about the unkown drug being used. Unfortunately, in Kaplan and First Aid this information is scattered in a difficult to study manner.

THE SOLUTION: If you have Lippincott's Pharmacology, go to page 174 (figure 17.2). This is a full page sized reader-friendly figure showing the different arrhythmias and the anti-arrhythmics that can be used. It is very organized and I highly recommend you refer to this. If you don't have the book, email me and I will scan this page for you.

Reserpine

RESERpine acts by depleting RESERves of Norepinephrine in neurons.

People who took reserpine became severely DepRESsed

Speaking of Depression, here are the drugs that can induce depression:
PROMS:
Propranolol
Reserpine
Oral contraceptives
Methyldopa
Steroids

Bosentan

Bos-EN-t-AN is an ENdothelin receptor ANtagonoist.

Vasodilator Vessel Specificity

Vasodilators are commonly used in clinical practice, so make sure to get these facts straight.

Arteriolar Vasodilators: Calcium channel blockers, Potassium channel blockers, and Hydralazine. These cause reflex tachycardia and edema.

Venular dilators: Nitrates. These cause orthostatic hypotension.

Drugs that are Both Arteriolar and Venular dilators: all other vasodilators. These cause reflex tachycardia, edema, AND postural hypotension. A prime example would be alpha-1 blockers such as prazosin.

***There are 3 important dilators that act via increasing NO. These are Nitrates (venular), Hydralazine (arteriolar), and Nitroprusside (both).

Order of Subjects

Today I was asked a very good question on one of the usmle forums. The student asked me what the best order is to review the subjects for Step 1. The most logical method is to study them in the same order you took these classes in Med School. Start with subjects that don't need a lot of integrations with other subjects. For example, here is the order I am using:

1. Anatomy
2. Biochemistry
3. Physiology
4. Microbiology
5. Pathology
6. Pharmacology
7. Behavioral Sciences

Now, for the last 3 subjects, you may prefer to switch these around, and it would be okay. Please note that Pathology integrates almost all of the other subjects you've studied (makes sense since it's the main bulk of the USMLE step 1). You can do Pharm before Pathology if you want to take advantage of the Pharm integration in Rapid Review Pathology (however there aren't that many of them). I recommended Behavioral Sciences after Pharmacology because BS (lol) has a psychopharmacology section that requires you to have some background in Pharm.
I recently came across an excellent study guide for the USMLE by someone called Taus on SDN. I highly recommend it. It integrates several subjects well and is overall an excellent guide that you can mend to best fit you. Here is the link for it:
http://forums.studentdoctor.net/showthread.php?p=6192274#post6192274
If you guys have any further suggestions or questions, feel free to comment.

Bethanechol vs. Methacholine

As a med student, you have to make up ridiculous methods for memorizing certain facts. Bethanechol and Methacholine are both muscarinic receptor agonists, but Bethanechol only affects Muscarinic receptors, while Methacholine activates both muscarinic and nicotinic receptors.
To memorize this, think of AcetylCHOLINE. MethaCHOLINE has the whole "CHOLINE" in it, therefore, like Acetylcholine, it activates both M and N receptors. BethaneCHOL has only half what Acetylcholine has, therefore it only activates M receptors.
Now you won't ever again forget what these 2 drugs do!

The Sneeze Drug

Some drugs have wacky names! I was reviewing some Pharm today and I came across the drug Eptifibatide. It sounds like you're sneezing if you say it like this EPTI-fibatide!

I spent almost an hour laughing about this today. I don't know if it's the long stressful hours of studying that have induced a mania-like state, or perhaps I was stressing about memorizing this hard-to-remember drug that my ego decided to use humor as a defense mechanism...but wait, defense mechanisms are supposed to be unconscious...so if I'm thinking about it being a defense mechanism, then it probably isn't right? But does this statement hold for medical students and doctors, who are aware of the use of defense mechanisms? I'd like to know the answer to that.

Well, now that you've read about the drug that sounds like a sneeze, EPTI-fibatide, I might as well tell you what it is. It is an antiplatelet drug that acts as an antagonist on gp IIb/IIIa (receptors for fibrinogen, required for platelet adhesion). Note that this is the same receptor that is deficient in Glanzmann's disease.

I hope this helps!

Alright! Let's get the ball rolling! I'm going to be writing the USMLE step 1 in July 2010. My goal is to score 240/99 or higher. In this blog I will post updates on how my USMLE Step 1 prep is going and tips that will help you during YOUR USMLE Step 1 Prep. I will also post mnemonics and tables that I've created to help you study some of the high yield material for the USMLE Sep 1.