Infectious Disease Compendium

General Concepts Concerning the Use of Antimicrobials and Infectious Diseases

1) There is nothing intrinsically 'powerful', 'strong', or 'big gun' about an antibiotic. The use of these terms is a reliable marker (sensitivity and specificity of 99% in my hands) that the speaker knows nothing about antibiotics. They are marketing concepts, no more helpful than the phrase ‘new and improved’. I think, without data in this instance, that antibiotics are not used as chemicals to kill organisms in a specific body space. Rather, they are magical talismans that are used to ward off evil spirits. Instead of possession by demons we have infection by Pseudomonas and instead of exorcism we give Zosyn. The words may have changed, but the thinking behind it remains unchanged.

2) There is nothing intrinsically good about 'broad-spectrum', the concept of which, like the terms mentioned in 1, may lead to a false sense of security that you are appropriately treating the patients infection. The good thing about broad-spectrum antibiotics is that they breed really resistant infections, which in turn leads to ID consultations, which in turn pays my mortgage. On second thought, maybe broad-spectrum antibiotics are not such a bad idea after all..........

3) Most antibiotics work most of the time in most patients. That is why 40% of the time we give antibiotics inappropriately in the in hospital, yet patients do just fine. Most of the time. There are diseases (sepsis, pneumonia, and endocarditis to give three examples) where giving the wrong antibiotics actually leads to a worse outcome. Such as death, Really. Giving an antibiotic to which the organism is resistant can be a bad idea. People can and do die if you choose wrong. And since 40% of the time antibiotics are given incorrectly, it is important that the hospital formulary reflect this. The antibiotics available for people who do not know what they are doing should be those that can do the least harm. The formulary needs to protect patients not from the good doctors, but from those whose practice may be, shall we say, suboptimal.

4) Anyone who gets their information from a pharmaceutical rep is a self-deluded fool. Advertising works. Most doctors say they pay no attention to what drug reps say. But the data suggests that not only is the information one gets from the pharmaceutical rep wrong but it is their primary source of information on drugs. For the record, I have not talked to a rep, except for a terse hello, in over 15 years, and, with one exception (a rep sent be a Fleets enema. I have it proudly in my desk), have accepted nothing from industry. Unlike most of my colleagues, I have not whored myself. (But it is not to say I wouldn't. Given enough zeroes, my honor and integrity are for sale). Go to for the skinny.

5) I practice the "My Mothers Infected Prosthetic Valve Has To Be Treated Medically" or MMIPVHTBTM approach to infectious diseases. If antibiotic X is the best drug for MMIPVHTBTM, then why would I use an inferior antibiotic in other circumstances? The answer is, of course, I wouldn't.

6) ‘I like X and have used it to good effect over the years.’ If X equals a condiment you put on your cheeseburger, then that is a reasonable assertion. If X is an antibiotic, that makes no rational sense. Such an approach ignores all the difficulties of human memory and is not an appropriate paradigm for the prescription of antibiotics (or any other drug). If however, you say I use X because the in vitro and in vivo data support its use, it makes sense. It would not be good criteria for choosing condiments for your cheeseburger. So if your rationale for using a drug would be equally applied to mustard and onions, perhaps you should rethink the reasoning used for said drug.

7) In treating patients, then, we want to give antibiotics that kill the organisms that will kill our patients, and we want reliable empiric killing (in serious illnesses, empiric susceptibility bordering on 100%) and we want to give antibiotics that have good levels in the body fluid(s) that are infected, that are minimally toxic, that do not breed resistance and that are inexpensive. We want the most bang for the buck (ID doctors are all closet military men).

8) The best article ever is called Spiraling Empiricism, published in Am J Med. 1989 Aug;87(2):201-6. I suggest you take the time to find and read this classic that outlines many of the cognitive errors we all do when treating infections and, perhaps, other diseases. I would love to get permission to include the full text; someday I shall ask.

9) It is amazing how many times I get a consult or hear about a patient where it is evident the treating physician has no clue about the significance of a culture or what the best antibiotic is. Sending a S. aureus bacteremia home on po clindamycin is a good example. No one would treat a cancer without an oncologist or deliver a baby without Ob help, but for some reason people feel it is appropriate to screw up, er, I mean, take care of complex infections without ID input.

It is the classic example of the Dunning Kruger effect (Ref): "The Dunning–Kruger effect is a cognitive bias in which unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than average. "

The ID doc knows more than you about infections. Pay attention to what they say. For any number of infections following ID recommendations will improve care and decrease cost (PubMed).

10) The three most dangerous words in medicine: In my experience. If a doc wants to use an antibiotic (or any therapy) because in their experience it works, run. That is why we have evidence, to know how to treat infections. Also pay no attention to someone who 'likes' a given antibiotic. Treatments should not be chosen like a flavor of ice cream.

Are 'cidal' antiotics better than static? The data suggests no (PubMed). That being said, for meningitis, endicarditis and the neutropenic (not evaluated in this study) I would still try to kill rather than stun the bacteria. Outcomes in ID depend on sone indefinable ballance of source control, host immune system, virulence of the organism and the antibiotic. When the first two are lacking, you have to make it up with the last.

Curious Cases

Relevant links to my Medscape blog

Weird Rashes

Why is ID different?


Flying Pigs

There is much to be Thankful for


Rare Quasi-ethical Dilemma

Phone Call.

The Nevernever

No Problem

Premature Closure

A Quadruple Whinge



What is Worse than Drunk Driving?



Nailed It


The Worst Part of Being a Doctor

110 Years Ago

Everything is Going to Hell in a Hand Basket

Conflicts? Who can tell.

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