What do tigecycline, daptomycin, ceftaroline, have in common?
They are all relatively new broad spectrum antibiotics, to which various MDROs are often susceptible. They are also manufactured and marketed by pharmaceutical companies in whose basic interest it is that we use as much of these antibiotics as possible.
However to maintain the life expectancy of these antibiotics for use against MDROs, we actually have to do the opposite, i.e. use them as little as possible. These antibiotics really should only be used when we have no other reasonable or viable choices. They should essentially be protected antibiotics, and this is often the case in anti-microbial guidelines issued by Antimicrobial Stewardship committees.
How can the laboratory assist in this objective? Can they help?
It is my belief that the laboratory is of paramount importance in protecting antibiotics like these…..
The most important thing the laboratory can do is not to test or routinely report susceptibilities to these types of antibiotics, except when they are really needed. In this way usage can be targeted and antibiotic selection pressure can be minimised.
If every Gram negative isolate in blood cultures from the laboratory was released with tigecycline susceptibilities, not only would all the general clinicians be aware of this choice, but some would find a way to prescribe it, despite good stewardship guidelines being in place. Such a practice essentially normalises the antibiotic.
Much like some of the newer chemotherapeutic drugs should remain in the domain and expertise of oncologists, the same can be said for some of the newer antimicrobials staying in the domain of Infectious Diseases physicians and Clinical Microbiologists.
Sometimes it is better not to know…… Ignorance is bliss.