Adverse Drug Effects

Drugs, including herbal remedies and various dietary supplements, seldom exert their beneficial effects without also causing adverse drug effects (ADEs). The inevitability of this therapeutic dilemma lends credence to the statement that there are no “absolutely” safe biologically active agents. ADEs range from mild to severe reactions and can lead to hospitalization, permanent disability, or death. ADEs may be predictable and unpredictable (Table 3).

Table 3. Classification of adverse drug effects.

Predictable ADEs, with the exception of drug overdose, are associated with the administration of therapeutic dosages of a drug. Predictable ADEs are usually avoidable, and they are responsible for most ADEs. Unpredictable ADEs are generally independent of the dose and they are usually unavoidable. While they are uncommon, unpredictable ADEs are often among the most serious and potentially life threatening, e.g., anaphylactic reaction.

Healthcare providers must be actively involved in monitoring for and reporting ADEs. In 1993, the FDA launched MEDWatch, an initiative to educate healthcare professionals about the critical importance of being aware of, monitoring for, and reporting ADEs (Box B).20 It is designed for voluntary reporting of problems associated with medical products. Importantly, reporting does not require proof of causality; a suspected association constitutes sufficient reason to report.

Box B. Mechanisms to report ADEs.
  • FDA Form 3500 available at
    • Complete Form 3500 online
    • Complete a downloaded a copy of Form 3500
      • Fax it to 1-800-FDA-0178
      • Mail the completed, postage-paid and addressed form to the FDA
    • Call 1-800-FDA-1088 to report by telephone