Life is very unpredictable at times, but imagine how it must feel like to have no control over your body’s response to stress. This is part of everyday life for patients with familial dysautonomia (FD).
Without warning, their blood pressure surges, their heart races at more than 100 beats a minute, and they quickly become overwhelmed with nausea and cannot stop retching or vomiting. These episodes – which families often call a crisis – can be terrifying for patients. Uncontrollable crisis episodes frequently land patients in the hospital, sometimes for days on end.
While carbidopa has shown to be effective for the treatment of recurrent frequent crises, it has to be taken each day. Patients that do not have frequent episodes may not want to take a preventative medication every day. This leaves them with limited options at the times that they do have a crisis.
Three year ago, one of our patients had undergone spine surgery and immediately thereafter he began suffering a severe autonomic crisis. None of the usual measures were working and he was transferred to the intensive care unit. His father, an experienced anesthesiologist, suggested that we try a new compound dexmedetomidine (Precedex). What an excellent idea that turned out to be. Soon after, his blood pressure became under control, his heart rate slowed and his symptoms began to ease.
In 2015, the NYU Dysautonomia Center started collaborating with the Pharmacy Department to evaluate the effectiveness of dexmedetomidine in a bigger group of patients with FD. Each time patients were admitted to NYU for uncontrollable crisis and dexmedetomidine was administered, we methodically monitored their progress. In almost all people, the adrenergic crisis symptoms were under control within one hour and had completely resolved by the time the medication was weaned off. This means we now have a way to safely and effectively stop and acute adrenergic crisis induced due to emotions or illness. It enables us to treat the underlying cause, while making the patients comfortable.
Dexmedetomidine acts within the brain and spinal cord on α2 receptors. Its mechanism of action is somewhat similar to clonidine, but the drug is far superior and much more specific. Dexmedetomdine needs to be infused constantly because it acts for only a very short period of time. This is a great advantage, as it allows us to tightly regulate the dose at the touch of a button, allowing the effect of the drug can be stopped quickly. Importantly, it does not suppress the drive to breath, so it appears to be a safer alternative.
What is next?…
At the moment, dexmedetomidine can only be given IV while in the intensive care unit. But this may change. We are planning a clinical trial using this compound intranasally. Stay tuned.
Read more: Dillon RC, Palma JA, Spalink CL, Altshuler D, Norcliffe-Kaufmann L, Fridman D, Papadopoulos J, Kaufmann H. Dexmedetomidine for refractory adrenergic crisis in familial dysautonomia. Clin Auton Res. 2016 Oct 17. PMID: 27752785