Chemistry of drug allergenicity

Of the very large number and variety of drugs used in medicine, those that are frequently implicated in immediate allergic reactions are relatively small in number and include neuromuscular blocking drugs used in anaesthesia, beta-lactam antibiotics, some other antibacterial agents including broad-spectrum antibiotics and quinolones and, less often, some narcotics. Structure-activity and immunochemical investigations have been most numerous and detailed for neuromuscular blocking drugs and beta-lactams, particularly penicillins. For the former group of drugs, morphine is proving to be a useful agent for the in-vitro detection of clinically relevant neuromuscular blocking drug-- as well as morphine- and fentanyl-reactive IgE antibodies. The employment of so-called 'major' and 'minor' determinants for a range of different penicillins and cephalosporins has revealed previously unsuspected heterogeneity in patient recognition responses, and has reinforced findings on the allergenic importance of side-chain groups. Many reports have been published on anaphylaxis to chlorhexidine, and progress in identifying allergenic determinants is reviewed together with the still inadequately understood subject of IgE antibody recognition of quinolone antibacterial agents.