adverse drug reaction

• Type A reaction – an extension of the pharmacology of
the drug, dose related, and accounts for most adverse
reactions (e.g. ß-adrenoreceptor antagonist-induced
bradycardia or AV block).
• Type B reaction – idiosyncratic reaction to the drug, not
dose related, rare but severe (e.g. chloramphenicolinduced
aplastic anaemia).
• Other types of drug reaction (much rarer):
– type C reaction – continuous reactions due to longterm
use: analgesic nephropathy;
– type D reaction – delayed reactions of
carcinogenesis or teratogenesis;
– type E reaction – drug withdrawal reactions (e.g.
benzodiazepines).