what antibiotic to give for a particular bug - helpful figures?

[aashkab]

Hi,

I am finding myself missing a lot of the questions where I know the organism causing the infection and can't select between two antibiotics. I've tried using those first AID pnemonics (not really my style) but I also find a lot of inconsistencies in the Kaplan/USMLERX qbanks about it also.

Is there a certain figure or table in another source that I can look at it all at once, basically just bacteria - drug. boom. as simple as that.

I'm looking through CMRS and its tables are decent but still find it a bit overwhelming to pick out the info.

Worst comes to worse, I'll have to start compiling my own.

Thanks for the help.

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[PokerDoc]

This has been my biggest weakness too, and the problem is.. no chart like this exists b/c theres always more than one choice.

If you look at the questions, it always says which of the FOLLOWING drugs is the best treatment, not.. which drug is the best treatment.. In the real world, and doctor will tell you always give your patient X when he has Y.. but on the exam, X may not be an answer choice and you have to chose the next best thing.


I've asked this question to a lot of 3rd years, and the best answer I've gotten was to spend more time studying drug mechanisms, adverse reactions and side-effects, rather than what bug cures what drug. Those seem to be more consistent and more high yield.

 

[kryptik]

when you cannot figure out an antibiotic and you have to guess use this generality

G +ve - cell wall inhibitor
G -ve - protein synthesis inhibitor

 

[HTxFrog]

I feel like there are certain things they want you to know, but you don't really need to know every bug a particular drug covers. I usually think about it like intracellular/weird atypical stuff like chlamydia mycoplasma legionella rickettsia etc. use tetracycline/macrolide and normal gram + use a penicillin/cephalosporin. Use penicillinase resistant penicillins (nafcillin dicloxacillin) for staph unless mrsa then use vancomycin. Clindamycin for anaerobes above diaphragm. Metronidazole for anaerobes below diaphragm. TB drugs for TB. Later generation cephs kill more gram - stuff. Ampicillin w/ gentamycin will kill a bunch of gram negatives and stuff if thats a choice. Imipinem/cilastatin for enterobacter. Metronidazole for C. dificile or vancomycin if metronidazole isn't a choice. TMP-SMX for UTI or sometimes a fluoroquinolone if tmp-smx isn't a choice. Triple-therapy for h. pylori. Ceftriaxone + Azithromycin or Doxycyline for suspected chlamydia/gonorrhea b/c they coinfect. CAP usually macrolides. Idk there definitely isn't a chart you can memorize for this though. If you know those specific infection treatment combos you can get most of the questions (if anyone can think of more feel free to add).

 

[lord_jeebus]

I feel like there are certain things they want you to know, but you don't really need to know every bug a particular drug covers. I usually think about it like intracellular/weird atypical stuff like chlamydia mycoplasma legionella rickettsia etc. use tetracycline/macrolide and normal gram + use a penicillin/cephalosporin. Use penicillinase resistant penicillins (nafcillin dicloxacillin) for staph unless mrsa then use vancomycin. Clindamycin for anaerobes above diaphragm. Metronidazole for anaerobes below diaphragm. TB drugs for TB. Later generation cephs kill more gram - stuff. Ampicillin w/ gentamycin will kill a bunch of gram negatives and stuff if thats a choice. Imipinem/cilastatin for enterobacter. Metronidazole for C. dificile or vancomycin if metronidazole isn't a choice. TMP-SMX for UTI or sometimes a fluoroquinolone if tmp-smx isn't a choice. Triple-therapy for h. pylori. Ceftriaxone + Azithromycin or Doxycyline for suspected chlamydia/gonorrhea b/c they coinfect. Idk there definitely isn't a chart you can memorize for this though. If you know those specific infection treatment combos you can get most of the questions (if anyone can think of more feel free to add).

This is excellent.

Remember that PO Vancomycin works for C. diff colitis, but IV does not.

Also know what drugs kill pseudomonas. Empiric therapies for bacterial meningitis, community-acquired PNA, hospital-acquired PNA.

 

[PokerDoc]

I feel like there are certain things they want you to know, but you don't really need to know every bug a particular drug covers. I usually think about it like intracellular/weird atypical stuff like chlamydia mycoplasma legionella rickettsia etc. use tetracycline/macrolide and normal gram + use a penicillin/cephalosporin. Use penicillinase resistant penicillins (nafcillin dicloxacillin) for staph unless mrsa then use vancomycin. Clindamycin for anaerobes above diaphragm. Metronidazole for anaerobes below diaphragm. TB drugs for TB. Later generation cephs kill more gram - stuff. Ampicillin w/ gentamycin will kill a bunch of gram negatives and stuff if thats a choice. Imipinem/cilastatin for enterobacter. Metronidazole for C. dificile or vancomycin if metronidazole isn't a choice. TMP-SMX for UTI or sometimes a fluoroquinolone if tmp-smx isn't a choice. Triple-therapy for h. pylori. Ceftriaxone + Azithromycin or Doxycyline for suspected chlamydia/gonorrhea b/c they coinfect. CAP usually macrolides. Idk there definitely isn't a chart you can memorize for this though. If you know those specific infection treatment combos you can get most of the questions (if anyone can think of more feel free to add).

I just copied and pasted this and printed it out and put on top of my FA.. thanks lol

 

[blahwhatever]

I feel like there are certain things they want you to know, but you don't really need to know every bug a particular drug covers. I usually think about it like intracellular/weird atypical stuff like chlamydia mycoplasma legionella rickettsia etc. use tetracycline/macrolide and normal gram + use a penicillin/cephalosporin. Use penicillinase resistant penicillins (nafcillin dicloxacillin) for staph unless mrsa then use vancomycin. Clindamycin for anaerobes above diaphragm. Metronidazole for anaerobes below diaphragm. TB drugs for TB. Later generation cephs kill more gram - stuff. Ampicillin w/ gentamycin will kill a bunch of gram negatives and stuff if thats a choice. Imipinem/cilastatin for enterobacter. Metronidazole for C. dificile or vancomycin if metronidazole isn't a choice. TMP-SMX for UTI or sometimes a fluoroquinolone if tmp-smx isn't a choice. Triple-therapy for h. pylori. Ceftriaxone + Azithromycin or Doxycyline for suspected chlamydia/gonorrhea b/c they coinfect. CAP usually macrolides. Idk there definitely isn't a chart you can memorize for this though. If you know those specific infection treatment combos you can get most of the questions (if anyone can think of more feel free to add).

That's really helpful, thank you!

 

[DiscoDoc]

I feel like there are certain things they want you to know, but you don't really need to know every bug a particular drug covers. I usually think about it like intracellular/weird atypical stuff like chlamydia mycoplasma legionella rickettsia etc. use tetracycline/macrolide and normal gram + use a penicillin/cephalosporin. Use penicillinase resistant penicillins (nafcillin dicloxacillin) for staph unless mrsa then use vancomycin. Clindamycin for anaerobes above diaphragm. Metronidazole for anaerobes below diaphragm. TB drugs for TB. Later generation cephs kill more gram - stuff. Ampicillin w/ gentamycin will kill a bunch of gram negatives and stuff if thats a choice. Imipinem/cilastatin for enterobacter. Metronidazole for C. dificile or vancomycin if metronidazole isn't a choice. TMP-SMX for UTI or sometimes a fluoroquinolone if tmp-smx isn't a choice. Triple-therapy for h. pylori. Ceftriaxone + Azithromycin or Doxycyline for suspected chlamydia/gonorrhea b/c they coinfect. CAP usually macrolides. Idk there definitely isn't a chart you can memorize for this though. If you know those specific infection treatment combos you can get most of the questions (if anyone can think of more feel free to add).

thanks, Frog!!

 

[aashkab]

I feel like there are certain things they want you to know, but you don't really need to know every bug a particular drug covers. I usually think about it like intracellular/weird atypical stuff like chlamydia mycoplasma legionella rickettsia etc. use tetracycline/macrolide and normal gram + use a penicillin/cephalosporin. Use penicillinase resistant penicillins (nafcillin dicloxacillin) for staph unless mrsa then use vancomycin. Clindamycin for anaerobes above diaphragm. Metronidazole for anaerobes below diaphragm. TB drugs for TB. Later generation cephs kill more gram - stuff. Ampicillin w/ gentamycin will kill a bunch of gram negatives and stuff if thats a choice. Imipinem/cilastatin for enterobacter. Metronidazole for C. dificile or vancomycin if metronidazole isn't a choice. TMP-SMX for UTI or sometimes a fluoroquinolone if tmp-smx isn't a choice. Triple-therapy for h. pylori. Ceftriaxone + Azithromycin or Doxycyline for suspected chlamydia/gonorrhea b/c they coinfect. CAP usually macrolides. Idk there definitely isn't a chart you can memorize for this though. If you know those specific infection treatment combos you can get most of the questions (if anyone can think of more feel free to add).

awesome! thanks man.

the pseudomonas killer is ticar, piper, carbeni -cillins

 

[greg1184]

I feel like there are certain things they want you to know, but you don't really need to know every bug a particular drug covers. I usually think about it like intracellular/weird atypical stuff like chlamydia mycoplasma legionella rickettsia etc. use tetracycline/macrolide and normal gram + use a penicillin/cephalosporin. Use penicillinase resistant penicillins (nafcillin dicloxacillin) for staph unless mrsa then use vancomycin. Clindamycin for anaerobes above diaphragm. Metronidazole for anaerobes below diaphragm. TB drugs for TB. Later generation cephs kill more gram - stuff. Ampicillin w/ gentamycin will kill a bunch of gram negatives and stuff if thats a choice. Imipinem/cilastatin for enterobacter. Metronidazole for C. dificile or vancomycin if metronidazole isn't a choice. TMP-SMX for UTI or sometimes a fluoroquinolone if tmp-smx isn't a choice. Triple-therapy for h. pylori. Ceftriaxone + Azithromycin or Doxycyline for suspected chlamydia/gonorrhea b/c they coinfect. CAP usually macrolides. Idk there definitely isn't a chart you can memorize for this though. If you know those specific infection treatment combos you can get most of the questions (if anyone can think of more feel free to add).

Excellent compilation. One question on my NBME 6 actually addresses this. It had a presentation of Strep and asked for the antibiotic. You might have helped many many people Frog.

 

[Nesiritide]

That is an excellent overview. I would also add TMP-SMX for PCP pneumonia, dapsone for leprosy, penicillin for syphilis, rifampin for n. meningitidis prophylaxis, ceftriaxone or any 3rd generation cephalosporin for empiric meningitis, plus ampicillin for listeria in the very young/very old.

 

[username456789]

I feel like there are certain things they want you to know, but you don't really need to know every bug a particular drug covers. I usually think about it like intracellular/weird atypical stuff like chlamydia mycoplasma legionella rickettsia etc. use tetracycline/macrolide and normal gram + use a penicillin/cephalosporin. Use penicillinase resistant penicillins (nafcillin dicloxacillin) for staph unless mrsa then use vancomycin. Clindamycin for anaerobes above diaphragm. Metronidazole for anaerobes below diaphragm. TB drugs for TB. Later generation cephs kill more gram - stuff. Ampicillin w/ gentamycin will kill a bunch of gram negatives and stuff if thats a choice. Imipinem/cilastatin for enterobacter. Metronidazole for C. dificile or vancomycin if metronidazole isn't a choice. TMP-SMX for UTI or sometimes a fluoroquinolone if tmp-smx isn't a choice. Triple-therapy for h. pylori. Ceftriaxone + Azithromycin or Doxycyline for suspected chlamydia/gonorrhea b/c they coinfect. CAP usually macrolides. Idk there definitely isn't a chart you can memorize for this though. If you know those specific infection treatment combos you can get most of the questions (if anyone can think of more feel free to add).

Nice.

And I've gotten several UTI-type questions right just based on the fact that I know Cipro and Bactrim are commonly prescribed for them (and I know their generics).