Think About Antibiotics Like We Think About Chemotherapy

Recently, I gave a talk on antibiotics to a small group of medical students and residents. After discussing common bacterial pathogens and the antimicrobial agents that target them, we turned to our list of inpatients on the ID service for review of their antibiotic histories. Each patient had been given more than a handful of different antibiotics since arrival, but the students and residents were unsure of why the empirical antibiotics were chosen in the ED, whether antibiotics deserved to be changed because of new data or exam findings, or what side effects and toxicities needed to be considered.

I was quickly reminded of how casually antibiotics can be ordered and administered, even when unnecessary or inappropriate. I realize that microbiology and pharmacology are hard topics — after all, infectious disease physicians like myself spend our entire careers studying the relationship between the two so that we can make expert clinical judgements. That being said, any physician who identifies infection and orders antibiotics should be knowledgeable about common pathogens and competent in choosing appropriate treatments.

Yet, I think antibiotics are often prescribed with limited consideration of a patient's differential diagnosis, potential causative microbiology, appropriateness of treatment and duration, possible side effects, or long-term consequences. As I struggled to convey the importance of these concepts to my students and residents, it hit me: What if we thought about antibiotics like we think about chemotherapy?

Is Treatment Even Necessary?

I'm sure that my colleagues in hematology/oncology consider many variables before planning a course of chemotherapy for a diagnosis of cancer. Sadly, for some patients, there may be no benefit to treatment, or the treatment may cause more harm than good. The same is true for infectious concerns. Some infections are incurable, while other infections resolve with intervention or the help of our immune system over time.

Before offering antibiotics, a provider should always ask themselves if a treatment regimen is necessary, beneficial, or risky. Chronic pelvic osteomyelitis and decubitus ulcers in a paraplegic who has undergone multiple surgical interventions, bone resections, and prolonged antibiotic courses? They may have reached a point of incurable disease. That isolated boil due to MSSA that you lanced? The drainage was the cure. The salmonella food poisoning case? The primary treatment is often just fluids and electrolyte replacement, not antibiotics.

Does the Treatment Target the Disease?

You can be sure that oncologists wouldn't include chemotherapy agents in a treatment regimen unless they targeted the cancer of concern. Likewise, antibiotics only work if they have activity against the pathogen causing the infection.

If it is determined that an infection necessitates antimicrobial treatment, the bug must be matched with the drug. To prevent a mismatch, consider the infectious diagnosis — if you don't know what organisms might be responsible, LOOK IT UP. If you can't remember which antibiotics target those organisms, LOOK IT UP. Avoid obtaining cultures that aren't interpretable for infection and cause inappropriate antibiotic use (for example, swab cultures of open wounds). If you're still struggling after doing your due diligence, consider an infectious disease consultation.

Is the Risk for Harm Worth the Benefit?

Chemotherapy agents are dangerous — they can interact with other drugs, cause impressive side effects, and lead to toxic consequences. Unfortunately, we seem to forget that antibiotics are hazardous, too, and for all the same reasons. A good provider will always consider the potential harm an antibiotic might cause while weighing it against the good it can offer.

Always ask about allergies and reactions before considering an antibiotic; there is often more to the story than what is listed in the chart. Drug interactions with antibiotics are common and can be hard to remember, so LOOK IT UP. Some antibiotics need to be closely monitored with drug levels and/or labs — if you're willing to prescribe it, you're accepting responsibility for monitoring it, too. Remember that antibiotics can be associated with considerable morbidity (such as drug-induced lupus or Clostridioides difficile colitis) or fatal reactions (such as anaphylaxis or Stevens-Johnson Syndrome).

Is the Course of Treatment Ideal?

Once an oncologist has determined an appropriate course of treatment, it is unlikely that they would order additional rounds of chemotherapy "just to be sure the cancer is gone." Yet, providers do this all the time with antibiotics, which increases the risk for side effects, adverse events, and antimicrobial resistance.

To be honest, as an ID consultant, I spend far more time stopping antibiotics than I do ordering them. That red and blistered leg that persists after 10 days of appropriate antibiotics for cellulitis? It's not because the beta-strep pathogen wasn't adequately treated, but rather the consequence of topical agents, dependent erythema, and continued edema. The cough that lingers after appropriate treatment for pneumonia, despite improvement in all other symptoms and a resolving x-ray? That's not due to ongoing infection or in need of a second course of antibiotics.

Is the Treatment Individualized for the Patient?

Heme/onc providers consider many other factors for their patients with cancer when tailoring their treatment over time: patient motivation, treatment failures or successes, organ dysfunction, and overall tolerance. We should be willing to do the same with antibiotics.

A patient might take an antibiotic pill twice a day but would never comply with a four times daily regimen. A concern for treatment failure should prompt reconsideration of the condition and the antibiotic regimen; an incorrect diagnosis may be just as likely as an inappropriate treatment choice or inadequate duration. Antibiotics should only be prescribed after review of organ function and confirmation of recommended dosing, and some patients will require ongoing assessment of organ function while on treatment.

As I continued to discuss these antibiotic/chemotherapy analogies with my students and residents, I began to sense a shift in their attitudes. They became less cavalier about randomly suggesting antibiotics for any given diagnosis. They frequently looked up a disease and its recommended antibiotic treatment before voicing an opinion during rounds. They were more willing to stop antibiotics if deemed inappropriate or potentially harmful. Maybe if we try harder to give antibiotics, like chemotherapy, the respect they deserve, we'd all do better by our patients.

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About Dr Roni Devlin

Roni K. Devlin, MD, MBS, is an infectious diseases physician currently residing in the Midwest. She is the author of several scholarly papers and two books on influenza. With a longstanding interest in reading and writing beyond the world of medicine, she has also owned an independent bookstore, founded a literary nonprofit, and published articles and book reviews for various online and print publications. You can reach her via LinkedIn.

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