[Interactions and adverse drug reactions: how to obtain information].

Adverse drug reactions (ADR) are common. They may mimick many other diseases. It is therefore important to consider always ADR as possible causes for new complaints. Interactions are less common but they may also be the source of serious problems. First informations on both topics are commonly found in the Swiss Drug Compendium ("Arzneimittel-Kompendium der Schweiz") and in the accompanying "Grundlagen der Pharmakotherapie". Further information is found in several standard text books, on new substances eventually also via the internet. Rare side-effects require a Medline-search or eventually consultation of the WHO-database on ADR. Several institutions in Switzerland provide information on ADR (an index is found in an annex of the "Arzneimittel-Kompendium der Schweiz"). It is essential for drug safety monitoring that every physician communicates observation of ADR.