Question – What do you do when bacterial pathogens are developing resistance to available medicines faster than new therapies are being introduced to take their place?
Doesn’t sound like a sustainable situation, does it? Unfortunately it’s a very real situation in developed countries around the world. Strains of bacteria like methicillin-resistant Staphylococcus aureus (MRSA) have evolved in both hospital and community settings, and while MRSA is currently getting most of the press, the scary reality is that other strains are emerging that are even more deadly. Today, even most MRSA infections can be treated using a last-line antibiotic such as vancomycin. The problem arises when drugs like vancomycin are used more frequently because they are the only effective alternatives available. Only slightly less sure than death and taxes, is the relationship between use of an antibiotic and the subsequent ability of bacteria to develop and pass on resistance to that antibiotic. This is why original life-savers like first generation penicillins are no longer generally useful to us for treating modern day infections. It’s also why we have to be very careful about the use of vancomycin and our other last-line antibiotics.
Increasingly, hospital administrators are adopting programs to control and monitor the use of antibiotics within their institutions. These programs, collectively referred to using the term “Antimicrobial Stewardship”, are designed to effectively limit the use of precious last-line antibiotic therapies to only the most serious cases of infection. Goals of antimicrobial stewardship also include elimination of antibiotic use in cases of non-bacterial infections (e.g. viral infections), optimization of dosing schedules, and achievement of uniformity in antibiotic prescribing practices. These programs are usually cross-functional efforts, and involve hospital pharmacists as well as clinicians, nurses, and administrators. A key attribute of most Antimicrobial Stewardship programs is the intent to achieve “evidence-based” prescribing practices, meaning that antibiotic therapies are carefully tailored to the diagnosis of a specific type of bacterial infection and take into account previous studies showing positive responses in treatment of that infection.
Antimicrobial Stewardship makes a lot of sense given the often haphazard approach to antibiotic therapy in hospitals. On a theoretical level, restriction of antibiotic usage will decrease the exposure of bacterial pathogens to a specific drug, and thus delay the ability to develop resistance mechanisms. Practically, published studies are now starting to show that Stewardship programs can result in measurable improvements such as decreases in both hospital stay and readmission rate.1 Regardless of the theoretical arguments for Antimicrobial Stewardship, continued practical demonstration of utility will be critical to the success of this movement in the future.
Detractors of antimicrobial stewardship claim that the practice doesn’t actually prolong the useful lifetime of antibiotics, or in fact delay the development of antibiotic resistance at all. They also contend that individual clinicians have the right to treat patients as they see fit, and should not be restricted in their treatment/prescribing practices. This individualistic point of view, especially popular in cultures like the United States, becomes controversial in this case because of the very nature of bacterial antibiotic resistance. It has been well documented that a major portion of antibiotic prescriptions are written by doctors as a “cover-all-bases” strategy, often with no definitive diagnosis of bacterial infection. This practice has been traditionally viewed as acceptable to clinicians, since most antibiotics cause only very minor side effects anyway. Furthermore, even if the case does not have a bacterial origin, the placebo effect can be a very powerful phenomenon and doctors know this well. Unfortunately, we know now that the effects of these over-prescribing practices extend well beyond a single case. Every unnecessary antibiotic prescription filled contributes a little bit more to the decreased usefulness of these drugs for the rest of us.
While still controversial, Antimicrobial Stewardship efforts certainly represent a step towards more responsible antibiotic prescribing practices in the face of growing bacterial resistance and widespread emergence of strains such as MRSA. An argument can certainly be made that antibiotics are a special class of medicine unto themselves, and that special controls on prescribing practices, administered correctly, could significantly prolong their utility. The key to making these programs the norm in hospitals, as always, will be the demonstration of measurable impact on infection rates and ultimately healthcare economics.
1 Mansouri et al. (2010) Infection. published online ahead of print on Feb 12, 2011