Type (A to F) of adverse drug reaction

A (augmented): common dose-related reaction, related to a pharmacological action of the drug, predictable and with low mortality.

B (bizarre): uncommon non-dose-related reaction, not related to a pharmacological action of the drug, unpredictable and with high mortality.

C (chronic): uncommon dose- and time-related reaction related to the cumulative dose.

D (delayed): uncommon reaction occurring sometime after the use of the drug, usually dose-related.

E (end of use): uncommon reaction that occurs soon after withdrawal of the drug.

F (failure): common dose-related unexpected failure of therapy reaction, often caused by drug interactions.