Position Statement

Position Statement: Medication Errors and Adverse Drug Reactions or Events

American College of Medical Toxicology
Kenneth Kulig, MD

Int J Med Toxicol 2001; 4(1): 13

Medication errors are mistakes involving pharmaceuticals, usually due to human error, whether or not patient harm results. Common causes of these mistakes include look-alike or sound-alike medications, illegible handwriting, misplaced or misinterpreted decimal points, wrong drug, wrong patient, wrong time, or wrong dose. Data are usually collected by hospital pharmacies, quality improvement departments, and physician peer review systems.

Adverse Drug Reactions (ADRís) are any undesirable effects of a drug. Adverse Drug Events (ADEís) include the omission of the properly prescribed medication due to noncompliance or medication error. Common causes of ADRís include known side effects, drug-drug interactions, drug-alternative medicine interactions, true drug allergies, and medication errors. Data are collected by the Medwatch program at the FDA, and by drug manufacturers who then also report them to the FDA. Underreporting is common, even among toxicologists. Preventable Adverse Drug Events are those caused by medication errors.

Medication errors and adverse drug reactions are common and costly. Estimates of hospitalized patients experiencing them has ranged from 1.5% to 35%, depending on the population studied, the adequacy of reporting, and the case definitions used. Fatal drug reactions are estimated to occur in 0.32% of hospitalized patients. Between 1.1 % and 8.5 % of all hospital admissions are reportedly caused by adverse drug reactions. Many of these cases are preventable, but this requires sufficient reporting, investigation, identification and elimination of systems errors, and aggressive education of health care providers.

Medical toxicologists, particularly those that are hospital based, are in a unique position to investigate the causes of, and help decrease the incidence of, both medication errors and adverse drug reactions in their institutions. By using their special skills and training, and becoming involved in groups such as the Pharmacy and Therapeutics Committee, medical toxicologists can directly improve patient care by helping to reduce the incidence of preventable adverse drug events. Educational presentations on these issues by toxicologists to their hospital staffs should be beneficial as well. They should encourage patients to be proactive in their care and to ask questions about their medications.

Toxicologists should help develop and encourage computerized order entry and other preventative measures (i.e. bar coding of medications) in their institutions whenever possible. ACMT encourages these practices among its members.

ACMT also encourages all of its members to be diligent in reporting medication errors to the hospital in which they occur, and ADRís to Medwatch at the FDA. This can be easily done via Internet: www.fda.gov/medwatch

Finally, ACMT encourages drug manufacturers to be very diligent at alerting physicians about potential problems they have identified such as in studies identifying potential adverse effects and mechanisms (whether to be published or remain unpublished), newly identified drug-drug interactions, patterns of serious ADRís , and sound-alike or look-alike medication errors. Toxicologist, like other physicians, need this information to properly care for their patients.


  1. Kohn LT, Corrigan JM, Donaldson MS, eds. To err is human: building a safer health system. Washington, D.C.: National Academy Press, 2000.
  2. Leape LL. Error in medicine. J Amer Med Assoc 1994; 272:1851-7.
  3. Brennan TA, Leape LL, Laird NM, et al. Incidence of adverse events and negligence in hospitalized patients- results of the Harvard Medical Practice Study I . New Engl J Med 1991; 324: 370-6.
  4. Thomas EJ, Struddert DM, Burstin HR, et al. Incidence and types of adverse events and negligent care in Utah and Colorado. Med Care 2000; 38:261-271.
  5. Bates DW, Cullen DJ, Laird NM, et al. Incidence of adverse drug events and potential adverse drug events : implications for prevention. J Amer Med Assoc 1995; 274: 29-34.
  6. Ruck B, Jennis T, Marcus S. Few NACCT abstracts of adverse drug reactions are reported to Medwatch. Int J Med Toxicol 2000; 3(2): 4.
  7. Leape LL, Brennan TA, Laird N, et al. The nature of adverse events in hospitalized patients: results of the Harvard Medical Practice Study II. N Engl J Med 1991; 324: 377-384.
  8. Dormann H, Muth-Selbach U, Krebs S, et al. Incidence and costs of adverse drug reactions during hospitalization. Drug Safety 2000 22(2): 161-168.
  9. Hasegawa GR. Responsibility for medication errors. Am J Health Syst Pharm 1999 56(3): 215.
  10. Bates DW. Frequency, consequences and prevention of adverse drug events. J Qual Clin Pract 1999 19(1): 13-17.

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