[Few drugs dominate among clinically important interactions. Swedish register study lists problem drugs].

In a recent Swedish register study, a limited number of specific drugs explained a large part of clinically relevant, potential drug-drug interactions (DDI), as defined and detected by the DDI database SFINX. Regarding interactions that should be avoided according to the definition in the database (class D), 15 drug combinations accounted for as much as 80 % of the prevalence in the Swedish population. Ten specific drugs were involved in 94 % of all detected class D interactions. About half of the clinically relevant interactions detected during the four-month study period were associated with an increased risk of adverse drug reactions, whereas the other half has a potential to cause therapeutic failure. An increased awareness among prescribers of these interacting drugs could contribute to safer and more effective drug use.