Reconciling Antimicrobial Choices with Patient Safety Concerns

In this era of patient safety, it makes little sense to use antimicrobials with dose-related toxicity unless no alternatives exist.

 Antimicrobials are designed to kill bacteria, fungi, and parasites, which are living organisms.  Human beings, also living organisms, share many metabolic processes with bacteria, so simple poisons can kill humans as well as infecting organisms.  Good antimicrobial design selectively kills the infecting organisms while leaving humans unharmed.

 There have been a number of antimicrobials with toxic potential for humans: chloramphenicol,  B, vancomycin, and the aminoglycosides are key agents that come to mind.  As antimicrobial development has progressed, many of these agents have been replaced with drugs that are significantly less toxic. 

 However, it appears that the replacement process is relatively slow in clinical practice.  For example, relatively safe broad-spectrum penicillins and cephalosporins that could cover Gram-negative organisms emerged in the late 1970s and early 1980s, but did not seriously supplant aminoglycosides as drugs of first choice until the 1990s, when they started to come off patent.  In fact, many orthopedists still employ aminoglycosides as prophylactic agents despite evidence that they are no more effective than more modern drugs.  Similarly, fluconazole was approved by the FDA in 1990 but was heavily restricted by U.S. hospitals due to its high cost, making the highly-toxic amphotericin B the preferred agent.  Under Medicare’s prospective payment system and the managed care practices of private insurers, hospitals could no longer pass on the increased costs to those third-party payers.  It wasn’t until fluconazole came off patent in 2005 that it broadly replaced amphotericin B as the drug of choice for initial antifungal therapy.

 It appears that, despite better safety profiles, initial proprietary drug costs restrict their use under Medicare and managed care systems.  This process is bolstered by clinical practices that favor the perpetuation of traditional management processes and look skeptically at new developments.  The paradigm shift that should occur in medicine is that patient safety should be worth the price we pay.