Several years ago, Janet Corrigan, the Director of the Institute of Medicine’s Board on Health Care Services, gave alarming testimony to the Senate Special Committee on Aging, on the subject of medication errors. She told the Committee that medication errors was one of the most common, preventable kinds of medical errors that harm patients. According to various studies, approximately 770,000 patients each year are killed or injured because of a medication error. It is estimated that at least half of these errors were preventable. A large percentage of the reported cases of medication errors occur in hospitals or nursing homes. Pharmacy medication errors have not been as well studied, although with nearly 3 billion prescriptions filled annually, a significant number of pharmacy medication errors is likely.

In a laudable, ongoing effort to reduce patient harm due to medication errors, the medical profession has identified a number of causes prevalent in many preventable medication mistakes. Systemic problems are a major factor in preventable medication errors. Systemic issues include physical factors such as poor lighting or chaotic organization, to errors of fatigue or distraction caused by pressure on pharmacists and pharmacy technicians, for a higher volume of drug preparation than can be safely performed. Miscommunication between pharmacists and doctors and nurses is another major cause of medication errors. Handwritten prescriptions by the physician may be misinterpreted by the pharmacist. Sound-alike and look-alike drug names, may result in the wrong drug being administered to the patient – a sometimes deadly mistake. In hospitals, some of the worst medication error tragedies occur when allergy information in a patient’s chart is overlooked, and the patient given a drug containing ingredients to which the patient is allergic. The wrong drug to the wrong patient is a significant source of error, as is the administration of an excessive drug dosage for the patient’s age, weight and condition.

Progress has been made in reducing medication errors. Since, however, there are many causes of preventable medication errors, there is no single, easy cure. Computerization of patient records, the conveyance of prescriptions from the doctor to the pharmacy, and checking for drug interactions, has significantly reduced drug errors in hospitals where such computerization has been implemented. Conditioning doctors to write drug names in full, rather than using abbreviations, prevents errors. Mistakes can be lessened with techniques as simple as making sure that a “0” is always placed before the decimal point when appropriate. Thus, for example, “0.25” is less likely to mistaken for “2.5” than is “.25”. Decades of bad habits need to be broken before medication errors disappear as a major cause of preventable patient injury and death. As medicine becomes more complicated, medication error reduction efforts will need to be sophisticated and persistent to be successful.