How to treat S. aureus?

[mrmandrake]

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Question for those who have taken the exam. I'm reading Kaplan Lecture Notes and it says that you treat S. aureus with "methicillin (and nafcillin)" unless it's MRSA in which case you use vancomycin. OK I get that.

I look to Wiki and it says oxacillin is a better choice than methicillin. WTF? So am I going to have to pick between these two drugs on the actual exam or will there only be one penicillinase-resistant penicillin in the choices?

I understand that a question might not be that simple but I just don't know how to make sense of all these different information sources and which one I should "go" with. Thanks!

 

[vicinihil]

Methicillin --> AIN = BAD so you don't use that anymore either

 

[McGillGrad]

Ignore wiki. Go with what is written in textbooks and review books because they reflect what is tested on the step.

As a side note, they would ask for the class and not ask you to differentiate two similar class members unless it is extremely common knowledge (such as the treatment of syphilis)

 

[Speculatrix]

Question for those who have taken the exam. I'm reading Kaplan Lecture Notes and it says that you treat S. aureus with "methicillin (and nafcillin)" unless it's MRSA in which case you use vancomycin. OK I get that.

I look to Wiki and it says oxacillin is a better choice than methicillin. WTF? So am I going to have to pick between these two drugs on the actual exam or will there only be one penicillinase-resistant penicillin in the choices?

I understand that a question might not be that simple but I just don't know how to make sense of all these different information sources and which one I should "go" with. Thanks!

Whoever said they would ask for "class of drug to treat" is completely wrong - they will give specific drugs. I don't know if you ever read CMMRS or even went to lecture in school, but one of the first sentences about METHICILLIN is that it is it is never used clinically anymore due to its extreme nephrotoxicity. It is used in labs, and also in the abbreviations MRSA and MSSA. Methicillin is NEVER USED and will NEVER be the answer on a test unless the vignette is about a lab (or someone in a third world country with renal failure).

Nafcillin is given only parenterally. Dicloxacillin is more stable for oral adminstration than oxacillin, and hence you would choose this for outpatient use. Vancomycin is only IV unless you are looking at C. difficile eradication. When they mean 'methicillin', it is really a stand-in for dicloxacillin, cloxacillin, oxacillin, and nafcillin, which are all kind of all part of one group (for MSSA). Know something about each of these drugs and just use your common sense.

I would advise you to re-read CMMRS or your micro notes and learn the material from first principles, because knowing this building block information will help you score much higher on the test, and differentiate you from drone-like rote memorizing IMG's.

 

[mrmandrake]

Thanks for all the feedback guys. I guess I've come to the conclusion that I can't have ONE resource for the boards and that I'll have to use different books. I do have CMMRS in a PDF and I'll go through that shortly.

When I first started reviewing for the boards I found a forum with mostly IMGs and they had like 6 months to study and were using mostly the Kaplan Lecture Notes as review. The Notes are 8 books and 3000+ pages so I figured they were a good resource to read along with my classes and people on that forum were posting some pretty high scores.

I am switching my strategy now and I'm going to scour these forums for the best books in each subject.

 

[Instatewaiter]

Question for those who have taken the exam. I'm reading Kaplan Lecture Notes and it says that you treat S. aureus with "methicillin (and nafcillin)" unless it's MRSA in which case you use vancomycin. OK I get that.

I look to Wiki and it says oxacillin is a better choice than methicillin. WTF? So am I going to have to pick between these two drugs on the actual exam or will there only be one penicillinase-resistant penicillin in the choices?

I understand that a question might not be that simple but I just don't know how to make sense of all these different information sources and which one I should "go" with. Thanks!

It really depends on the source and whether you know susceptibilities as to how you treat it. Susceptibilities in real life take days to come back even after you know it is S aureus.

MSSA- nafcillin is the standard treatment (or same class)
MRSA- Vanc, Daptomycin, or linezolid