Adverse drug reactions

Adverse drug reactions (ADRs) are important but often difficult to diagnose. They should be considered in the differential diagnosis of a wide range of conditions. Estimates of the proportion of acute hospital admissions caused by ADRs range from 0.5% to 12.8%. They can be classified according to dose-relatedness, time course and susceptibility. Toxic effects are caused by high doses, for example nephrotoxicity with aminoglycosides. Collateral effects are encountered within the therapeutic range, as for Clostridioides difficile infection with broad-spectrum antibiotics.