[Acute side-effects of drugs. Causes and prevention].

A successful therapy with causative acting drugs (e.g. antibiotics, hormones) or with symptomatic acting drugs (e.g. antihypertensive, psychopharmacological drugs, anticoagulants) cannot be practicable without secondary effects. These unavoidable "side-effects" either are of no consequence or, these have to be risked and to be controlled, especially in long-term-therapy. Often, it is impossible to foresee allergic reactions. Avoidable "side-effects" may be dangerous in case of patient's self-medication, medical negligence or in case of drug interactions. 5 classes of drugs with possible threatening secondary effects are demonstrated: glykosides, sulfonylureas (antidiabetics), coumarin derivatives (anticoagulants), corticosteroids and parenteral contrast mediums.