[Pharmaceutical, pharmacokinetic and dynamic interactions in tumor drug therapy]

Because of unfavourable therapeutic index application of cytostatic agents is often leading to adverse drug interactions. To avoid that kind of results it is important to know risks, early symptoms and possibilities of prevention. Recent observations show a potential occupational hazard for personnel handling cytostatic drugs by aerosols or direct contact (in-vitro-interactions). In cancer patients multimorbidity is not unusual. Drugs for the treatment of these diseases or the treatment or prevention of toxicity may interact with cytostatics (in-vivo-interactions) by influencing the absorption, protein binding, active drug transport, metabolism and excretion (pharmacokinetic interactions) as well as by changing mechanisms of the intracellular uptake of drugs or regulation of physiological functions and by blocking receptors (pharmacodynamic interactions). Inducing synergism or antagonism loss or potentiation of effectively as well as toxic reactions may result. In medical practice we have to pay attention to known clinically important interactions. The importance of other possible but still unknown interactions has to be investigated. To avoid adverse drug interactions in patients the application of drugs should be restricted to only a few but indicated drugs of established effectivity.