Serotonin syndrome is thought to arise from serotonin excess. In many cases,
symptoms are mild and self-limiting. But serotonin syndrome can become life
threatening, when neuromuscular hyperexcitability spins out of control.
Uncontainable neuromuscular hyperexcitability may lead to cardiovascular
complications, linked to extreme changes in blood pressure. Currently, there is
little guidance on how to control blood pressure in hyperserotonergic states. We
report a case with treatment-resistant arterial hypertension, followed by a
clinical review (using systematic review principles and techniques) of the
available evidence from case reports published between 2004 and 2016 to identify
measures to control arterial hypertension associated with serotonin syndrome. We
conclude that classic antihypertensives may not be effective for the treatment
of severe hypertension associated with serotonin syndrome. Benzodiazepines may
lower blood pressure. Patients with severe hypertension not responding to
benzodiazepines may benefit from cyproheptadine, propofol or both. In severe
cases, higher cyproheptadine doses than currently recommended may be
necessary.