Response to Issue of Antimicrobial Storage

To the Editor: Arya writes that improper storage of antimicrobials may affect their potency and contribute to resistance. This is an important issue and is a known issue with respect to vaccines. However, Arya starts with some faulty and unsubstantiated premises.

First, very few commonly used antibiotics in the outpatient setting in the Unites States require constant storage at sub-zero temperatures.

Then the author fails to substantiate the statement “they are inadvertently subjected to harsh environment before administration to patients… . ” The author also fails to substantiate the supposition that a harsh environment leads to “a reduced effective potency.”

The author implies that the 1995 heat wave in Chicago affected the quality of medications, especially antimicrobials. I was present in Chicago as a medical student during this heat wave. What the author fails to realize is that hospitals and pharmacies are air-conditioned, very few areas lost power, and hospitals have back-up generators in case of power loss, so the heat wave did not affect medications stored in hospitals or pharmacies. It is doubtful that storage issues are a significant contributor to antimicrobial resistance and failure in the United States, and research within the United States would be more useful investigating other areas.

Because power is erratic in developing countries, and air conditioning may be unaffordable to many facilities, storage issues and resultant antimicrobial failure is more likely to occur in those countries. Certainly in those countries, such research should be undertaken and the author's suggestion of labeling medications with storage specifications may prove useful.

Degradation of antimicrobials due to improper storage in developing countries can indirectly affect the United States, because US residents may be purchasing these foreign-made and improperly stored drugs. It may be possible that the lack of or reduced potency of active ingredient detected in shipped foreign-made drugs mentioned in my paper is due, in part, to improper storage, rather than just improper manufacture.

Testing medication potency at point of usage is not feasible as one would need to develop an assay for every antimicrobial, and this assay would need to be available in every town or village in each country. The author fails to substantiate the statement that developing this assay “would be cost-effective.”

Two of the suggestions mentioned in my paper can help counteract this storage issue. First is eliminating over-the-counter dispensation of antimicrobials and limiting them to licensed pharmacies, whose storage mechanisms are monitored by the government. Second is the regulation of the manufacture, storage, and distribution of drugs to ensure their potency at the point of distribution to hospitals and pharmacies. Again, the feasibility and costs of these suggestions are yet to be determined.

In the last paragraph, the author's suggestion of syndrome-wise categorization on an individual community/hospital basis is interesting and warrants further consideration and possible emulation. However, there needs to be research as to whether this system implemented in 2004 has resulted in reduced resistance in the surrounding community, or at the very least, in nosocomial isolates in the hospital.

As a final note, my paper could not encompass all the issues that may be contributing to resistance in the United States I would also suggest research into the effects of antimicrobial use in farm animals, as well as the appearance of antimicrobials in groundwater/rivers/streams resulting from the disposal of leftover antibiotics into sewage systems (ie, “flushing them down the toilet”).