Pharmacists in organized health care systems should develop comprehensive, ongoing programs for monitoring and reporting adverse drug reactions (ADRs).1 It is the pharmacist’s responsibility and professional obligation to report any suspected ADRs. ADR-monitoring and reporting programs encourage ADR surveillance, facilitate ADR documentation, promote the reporting of ADRs, provide a mechanism for monitoring the safety of drug use in high-risk patient populations, and stimulate the education of health professionals regarding potential ADRs. A comprehensive, ongoing ADR program should include mechanisms for monitoring, detecting, evaluating, documenting, and reporting ADRs as well as intervening and providing educational feedback to prescribers, other health care professionals, and patients. Additionally, ADR programs should focus on identifying problems leading to ADRs, planning for positive changes, and measuring the results of these changes. Positive outcomes resulting from an ADR program should be emphasized to support program growth and development.
ASHP does not suggest that there is a predictable rate of incidence or severity of ADRs. The number and severity of ADRs reported in a given organization or setting would vary with the organization’s size, type, patient mix, drugs used, and the ADR definition used.
ASHP defines a significant ADR as any unexpected, unintended, undesired, or excessive response to a drug that
- Requires discontinuing the drug (therapeutic or diagnostic),
- Requires changing the drug therapy,
- Requires modifying the dose (except for minor dosage adjustments),
- Necessitates admission to a hospital,
- Prolongs stay in a health care facility,
- Necessitates supportive treatment,
- Significantly complicates diagnosis,
- Negatively affects prognosis, or
- Results in temporary or permanent harm, disability, or death.
Consistent with this definition, an allergic reaction (an immunologic hypersensitivity, occurring as the result of unusual sensitivity to a drug) and an idiosyncratic reaction (an abnormal susceptibility to a drug that is peculiar to the individual) are also considered ADRs.
Several other definitions of ADRs exist, including those of the World Health Organization (WHO),2 Karch and Lasagna,3 and the Food and Drug Administration (FDA).4
WHO: “Any response to a drug which is noxious and unintended, and which occurs at doses normally used in man for prophylaxis, diagnosis, or therapy of disease, or for the modification of physiological function.”
Karch and Lasagna: “Any response to a drug that is noxious and unintended, and that occurs at doses used in humans for prophylaxis, diagnosis, or therapy, excluding failure to accomplish the intended purpose.”
FDA: For reporting purposes, FDA categorizes a serious adverse event (events relating to drugs or devices) as one in which “the patient outcome is death, life-threatening (real risk of dying), hospitalization (initial or prolonged), disability (significant, persistent, or permanent), congenital anomaly, or required intervention to prevent permanent impairment or damage.”
For perspective, it may be helpful to note events that are not classified as ADRs. A side effect is defined by ASHP as an expected, well-known reaction resulting in little or no change in patient management (e.g., drowsiness or dry mouth due to administration of certain antihistamines or nausea associated with the use of antineoplastics). ASHP further defines a side effect as an effect with a predictable frequency and an effect whose intensity and occurrence are related to the size of the dose. Additionally, drug withdrawal, drug-abuse syndromes, accidental poisoning, and drug-overdose complications should not be defined as ADRs.
While individual health care organizations may need to apply ADR surveillance to different degrees for different groups of patients, ASHP believes it would be greatly beneficial if a common definition of ADRs were used in all settings to facilitate reporting, collective surveillance, and ADR-trend research.
A comprehensive ADR-monitoring and reporting program should be an integral part of an organization’s overall drug-use system. An ADR-monitoring and reporting program should include the following features:
1. The program should establish
a. An ongoing and concurrent (during drug therapy) surveillance system based on the reporting of suspected ADRs by pharmacists, physicians, nurses, or patients.5
b. A prospective (before drug therapy) surveillance system for high-risk drugs or patients with a high risk for ADRs.
c. A concurrent surveillance system for monitoring alerting orders. Alerting orders include the use of “tracer” drugs that are used to treat common ADRs (e.g., orders for immediate doses of antihistamines, epinephrine, and corticosteroids), abrupt discontinuation or decreases in dosage of a drug, or stat orders for laboratory assessment of therapeutic drug levels.6,7
2. Prescribers, caregivers, and patients should be notified regarding suspected ADRs.