The most common manifestation of overdosage of hydroxyzine pamoate is hypersedation. 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 levophed® (levarterenol) or aramine® (metaraminol).
Do not use epinephrine as hydroxyzine pamoate counteracts its pressor action. Caffeine and Sodium Benzoate Injection USP, may be used to counteract central nervous system depressant effects.
There is no specific antidote. It is doubtful that hemodialysis would be of any value in the treatment of overdosage with hydroxyzine. However, if other agents such as barbiturates have been ingested concomitantly hemodialysis may be indicated. There is no practical method to quantitate hydroxyzine in body fluids or tissue after its ingestion or administration.