We define an adverse drug reaction as "an appreciably harmful or unpleasant
reaction, resulting from an intervention related to the use of a medicinal
product, which predicts hazard from future administration and warrants pre
vention or specific treatment, or alteration of the dosage regimen, or with
drawal of the product." Such reactions are currently reported by use of WHO
's Adverse Reaction Terminology, which will eventually become a subset of t
he International Classification of Diseases. Adverse drug reactions are cla
ssified into six types (with mnemonics): dose-related (Augmented), non-dose
-related (Bizarre), dose-related and time-related (Chronic), time-related (
Delayed), withdrawal (End of use), and failure of therapy (Failure). Timing
, the pattern of illness, the results of investigations, and rechallenge ca
n help attribute causality to a suspected adverse drug reaction. Management
includes withdrawal of the drug if possible and specific treatment of its
effects. Suspected adverse drug reactions should be reported. Surveillance
methods can detect reactions and prove associations.