Clinically important drug interactions

Abstract

Much attention has been focused on adverse drug interactions during the last 15 years or so, and as a result many drug-drug interactions are now predictable and many of the unwanted consequences of using drug combinations can be avoided by simply adjusting the dosage of one or more of the interactants. As a result of this, there has been a considerable improvement in the safety and efficacy of therapy with drug combinations. Unfortunately, however, because much has been written and published with a lack of clinical perspective, the literature has become clogged with a sticky and impenetrable morass of irrelevant information much of which has been generated in animal studies or in single-dose pharmacokinetic studies in healthy subjects usually drawn from a young adult age group. Such studies can be of predictive value, but only if they mimic the clinical situation and if they relate to drug combinations and dosage regimes that are normally used in sick patients. Likewise a large number of uncorroborated or anecdotal observations on individual patients have appeared. These are useful if they stimulate other clinicians to report similar experiences in their own patients. However, if other reports are not forthcoming then the original report should be regarded as idiosyncratic and be accepted with some reservation as to its generality.