What's the best treatment to get rid of diphenhydramine overdose?

Let help: Fluids through an intravenous line (IV) , medicines to increase blood pressure, control an irregular heart rhythm, or control seizures , close monitoring of the heart and lungs , a breathing tube to help with breathing , other treatments based on complications that occur.

Emergency Room: Treatment for Diphenhydramine O/D may include: administration of activated charcoal, intravenous fluids, intubation, Sodium Bicarbonate (Cardiac), Physostigmine, & benzodiazpines or barbituates for seizures. REF: https://overdoseinfo.com/diphenhydramine-overdose/