Precedex Overdosage

The tolerability of dexmedetomidine HCl was noted in 1 study in which healthy subjects achieved plasma concentrations from 1.8-13 times the upper boundary of the therapeutic range. The most notable effects observed in 2 subjects who achieved the highest plasma concentrations were 1st-degree AV block and 2nd-degree heart block. No hemodynamic compromise was noted with the AV block and the heart block resolved spontaneously within 1 min.
Of 5 patients reported with overdose of dexmedetomidine hydrochloride in the phase II/III ICU sedation studies, 2 had no symptoms reported; 2 had bradycardia with or without hypotension; and 1 who received 20 times the upper limit of the therapeutic range had a cardiac arrest from which he was successfully resuscitated.
Because dexmedetomidine HCl has the potential to augment bradycardia induced by vagal stimuli, clinicians should be prepared to intervene. In clinical trials, atropine and glycopyrrolate were effective in the treatment of Precedex-induced bradycardia.