Paradoxical excitation on diphenhydramine may be associated with being a CYP2D6 ultrarapid metabolizer: three case reports.

摘要: Diphenhydramine is a widely used antihistaminic that frequently included in over-the-counter medications. Due to its sedating properties, diphenhydramine some hypnotic preparations. Occasionally, patients respond with paradoxical excitation. There are no studies on the prevalence of excitation healthy subjects. appears cause mild inhibition cytochrome P450 (CYP) 2D6 enzyme. This can be interpreted as competitive inhibition, suggesting may CYP2D6 substrate. When subjects have at least three active copies gene, they called ultrarapid metabolizers (UMs) and present high metabolic capacity for substrates. In United States, UMs account approximately 1% 2% population. We describe who reported diphenhydramine. These cases suggest UMs, converted compound causes due abnormally activity. Therefore, such individuals higher risk Although these only anecdotal from reports illustrate need larger, more formal responses metabolism.