At the end of the chapter, the reader will be able to:
Develop a general understanding of how problems occur in the use of medications.
Identify and describe eight types of drug-related problems.
Discuss relationships between drug-related problems and drug-related morbidity.
Medications are one of the key tools in the therapeutic management of disease. However, they are not always used in an ideal, or appropriate, manner.1,2 When medications are not used appropriately, patients may experience adverse events or fail to achieve their therapeutic goals. In turn, this results in suboptimal quality of life and wasted resources for our society.
Hepler and Strand have used the term “drug-related morbidity” to describe the phenomenon of therapeutic malfunction – the failure of a therapeutic agent to produce the intended therapeutic outcome.3 This concept encompasses both treatment failure and the production of new medical problems. Considering that drug-related morbidity accounts for at least 7% of hospital admissions and billions of dollars in unnecessary health care expenditures, drug-related morbidity is an important public health issue.4–6
Drug-related morbidity is often preceded by a drug-related problem (DRP).7 A DRP is an event or circumstance involving drug treatment that actually or potentially interferes with the patient experiencing an optimum outcome of medical care. Strand et al. delineated eight categories of DRPs:
Untreated indications: the patient is in need of a drug that was not prescribed.
Improper drug selection: the wrong drug is being used.
Subtherapeutic dosage: too little of an appropriate drug is being used.
Overdosage: the patient receives too much of an appropriate drug.
Failure to receive drug: the patient does not obtain/use the drug that was prescribed.
Adverse drug reaction: an unintended and potentially harmful effect of a drug.
Drug interactions: undesirable consequences of drug–drug or drug–food interactions.
Drug use without indication: the patient is taking a drug for which he or she has no medical need.7
DRPs may arise due to inappropriate prescribing, inappropriate dispensing/administration of the drug, inappropriate behavior by the patient, inappropriate monitoring of the patient, or patient idiosyncrasy. Although idiosyncrasy is inherently unpreventable, most of the other causes of DRPs can be prevented. The following section of this chapter will provide a framework for examining the causes of suboptimal medication use.
Hepler and Grainger-Rousseau's conceptualization of a pharmaceutical care system offers a good framework for examining the quality of medication use.8 The pharmaceutical care system is similar to the drug-use process described by Knapp et al.9 but adds the functions of drug monitoring and management to denote the importance of ongoing attention to the patient and drug regimen. Hepler and Grainger-Rousseau suggest that there are three key elements to the proper functioning of a pharmaceutical care system: (1) initiating therapy; (2) monitoring therapy; and (3) managing (i.e., correcting) therapy.