[Drug interactions].

Beneficial and adverse interactions between drugs may occur in any process that influences the pharmacokinetic and pharmacodynamic behaviour of a given drug and thus affects its therapeutic or toxic effects. Many additional "patient factors" and "drug factors" influence clinical occurrence and severity of adverse drug interactions. In dealing with drug interactions and their consequences, a uniform mode of classifying and reporting drug interactions based on clinical relevance appears to be the prime necessity. A number of adverse drug interactions commonly occurring during cardiovascular therapy are discussed.