[Serotonin syndrome and pain medication : What is relevant for practice?].

Serotonin syndrome is a dangerous and rare complication of a pharmacotherapy and can lead to death. Caused by unwanted interactions of serotonergic drugs, it is characterised by a neuroexcitatory triad of mental changes, neuromuscular hyperactivity and autonomic instability. Opioids with serotonergic effects include the phenylpiperidine series opioids fentanyl, methadone, meperidine and tramadol and the morphine analogues oxycodone and codeine. In combination with certain serotonergic drugs, e.g. antidepressants, they can provoke serotonin syndrome. In patients with such combinations, special attention should be paid to clinical signs of serotonergic hyperactivity. Higher risk combinations (e.g. monoamine oxidase inhibitors with tramadol) must be avoided. Treatment with serotonergic agents must be stopped in moderate or severe serotonin syndrome. Patients with a severe serotonin syndrome require symptomatic intensive care and specifically a pharmacological antagonism with cyproheptadine or chlorpromazine.