I have a pharmacological background and yes you can OD on hydroxyzine. It an antihistamine with several secondary uses i.e.non narcotic anti anxiety option." Yes, you can overdose on Vistaril. The most common manifestation of overdosage of Vistaril is hypersedation. Other reported signs and symptoms were convulsions, stupor, nausea and vomiting. As in the management of overdosage with any drug, it should be borne in mind that multiple agents may have been taken.If vomiting has not occurred spontaneously, it should be induced. Immediate gastric lavage is also recommended. General supportive care, including frequent monitoring of the vital signs and close observation of the patient, is indicated. Hypotension, though unlikely, may be controlled with intravenous fluids and vasopressors (do not use epinephrine as hydroxyzine counteracts its pressor action.) ".......excerpt from well known medication website.{ don't want to infringe on rights or violate trademark rules but if requested I'll gladly finish the foot note)
Also there is no benefit to taking more than prescribed by a practitioner. if you or someone you know of is planning to od please call your local crisis team, 911 or sponsor if in recovery. Im speaking from experience that life does improve and im glad i didnt finish the process