[Age 89 years, depression, fall with pelvic fracture, severe confusion - serotonin syndrome : Differential diagnosis, importance of CYP450 and economic considerations].

A case study of an 89-year-old patient is reported, who was admitted to hospital because of immobility due to pain. After the cause of the pain could initially be clarified and treated, the further clinical course in this very old woman showed an alarming symptom complex of agitation, confusion and cognitive deterioration, which took on grave forms. The work-up of this case showed a typical constellation of pain and depression in old age; however, the pharmaceutical treatment in this case is not atypical and could lead to a severe serotonin syndrome. The interaction, diagnostics, differential diagnosis, pharmacological, functional, codification and economic aspects of the course of the disease are discussed.