Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services for fainting, trouble breathing, a seizure, inability to wake, or a fast or irregular heartbeat with severe symptoms.
And for anyone, someone who:
Seek urgent medical advice after discharge for increasing sleepiness, repeated vomiting, new muscle stiffness, difficulty urinating, or worsening dizziness.
Follow-up needs depend on any complications and on the reason for the overdose.
Follow-up may include contact with a psychiatrist, therapist, primary care clinician, or crisis service.
The goal is to address the circumstances that led to the overdose and create a practical safety plan.
And for anyone, someone who:
The article also says
Before discharge, the healthcare team should confirm that alertness, blood pressure, breathing, walking ability, and heart findings are stable.
Do not restart, stop, or change chlorpromazine without speaking with the prescribing clinician.
After an overdose, the prescriber may review whether the medicine is still appropriate, whether the dose or packaging should change, and whether other medicines could interact with it.
After an accidental dosing error, a pharmacist can help simplify the schedule and check for duplicate products.
A locked storage box, supervised administration, or limited quantities may help prevent another exposure when appropriate.
An intentional overdose should be followed by a mental health and safety assessment.
Every sign above is quoted from the sofidex article on Chlorpromazine overdose. If you are not sure, err upward — it is always reasonable to be checked.