Assessment of patients in whom an allergic drug reaction is suspected
should include a carefully taken drug history. This should be followed
by diagnostic testing if it is available for the drug in question. If
neither an alternative therapeutic agent nor a diagnostic test is ava
ilable, then a provocation challenge or desensitization may be necessa
ry. Increased understanding of allergic drug reactions requires the fo
llowing: better pharmacoepidemiologic studies, improved in vitro and i
n vivo methods of studying the immune responses involved, and expanded
comparisons between the pharmacokinetics and pharmacodynamic effects
of drugs and their metabolites. Until improvements are made in these a
reas, the appropriate approach is to avoid the unnecessary use of drug
s. When a drug is required, patient risk factors for an allergic react
ion must always be weighed against the benefits of treatment.