title: [Therapy control in cardiology: serum level monitoring].
abstract: Treatment of cardiac patients with drugs of low therapeutic ratio (i.e. cardiac glycosides, antiarrhythmics) must be individualized to avoid undertreatment or intoxication with their often deleterious consequences. However, in most cases the dose-response effect cannot be predicted, especially in those instances in which the desired effect is hard to measure (e.g. intermittent arrhythmias). Very often a potentially useful drug is not effective because the applied dose is either too low or administered at incorrect intervals. An effective medication can also be incorrectly assumed to be intolerable when the dose administered is too high relative to the patient's impaired renal or liver function. Fixed application schedules will not be successful in the majority of cases due to the following large interpatient variables: absorption, distribution, elimination, biotransformation, protein and tissue binding, and effect on the target organ. If drug efficacy cannot be proven by clinical observation the determination of blood levels of substances with a narrow therapeutic ratio cen be helpful. However, an interpretation should only be made by considering the clinical condition of the patient and the inherent kinetic variables of the drug.
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000097:blood* / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000188:drug therapy*; D001711:Biotransformation; D002301:Cardiac Glycosides / Q000097:blood* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D008657:Metabolic Clearance Rate; D011485:Protein Binding
chemical_list: D000889:Anti-Arrhythmia Agents; D002301:Cardiac Glycosides
vernacular_title: Therapiekontrolle in der Kardiologie: Serumspiegel-Monitoring.