Lawrence Trissel has served as Director of Clinical Pharmaceutics Research, Division of Pharmacy at the University of Texas, M.D. Anderson Cancer Center, where he managed the development and compounding of specialty investigational drug products. Trissel has also been the Senior Research Products Manager, Pharmaceutical Resources Branch, Developmental Therapeutics Program, Division of Cancer Treatment at the National Cancer Institute, within the National Institutes of Health.
Trissel’s many major professional accomplishments include authoring Trissel’s 2 Clinical Pharmaceutics Database, the Handbook on Injectable Drugs, and Trissel’s Stability of Compounded Formulations. These publications remain leading references in clinical pharmaceutics for today’s practicing pharmacist.
The terms “drug stability” and “drug compatibility” have very different implications to drug manufacturers and regulators than to those who use drugs in clinical practice. These different perceptions of the issues lead to drugs being marketed with little or no information available on many real-life situations involving drug stability and compatibility.
In actual drug use situations, particularly intensive care and oncology treatment, drugs are used in a complex and changing milieu of other drugs and biologicals, solutions, delivery systems, and materials. The old dictum just to administer each drug separately cannot always be achieved and still deliver today’s intensive multiple-drug therapies. The delivery of multiple parenteral drugs through the same administration set or port is likely to be the most common situation. Our modern administration equipment is often designed to permit multiple-drug administration simultaneously, sequentially, or in a variety of pre-programmed patterns. Consequently, it is unlikely that we as a profession will be able to move beyond these problems; it is rather more likely that the problems of drug compatibility and stability will actually be exacerbated.
Therefore, pharmacy practitioners must develop strategies to minimize risk to the patient from drug stability and compatibility issues while facilitating the patient’s drug therapy, and do all of this in the absence of complete information. It is a balancing act that is not easy to accomplish. Drug therapy needs may run afoul of drug compatibility options. Or maybe no information is available at all.
Consideration must be given to the drug’s chemical stability, an issue of great importance. But this information is expensive and difficult to obtain. Furthermore, most practicing pharmacists are not in a position to routinely perform drug stability testing. Of equal importance are the issues of physical incompatibilities, and these are certainly evaluable by practicing pharmacists, at least in simple aqueous admixtures. Examples of physical phenomena include haze, precipitate, color change, and gas evolution.
What can you do when you are faced with a situation where admixture or simultaneous administration of drugs is being contemplated, but inadequate or no information is available? Several options should be considered and these will be discussed. But, in the midst of these options, the most important is to balance all of the therapeutic and pharmaceutic concerns, always keeping the patient’s best interests paramount.
Quoted from the 2007-2008 Philip C. and Ethel F. Ashby Lecture Announcement Announcement Brochure