Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
A suspected meprobamate overdose is an emergency, even if the person is still awake.
Contact emergency services or a poison centre immediately.
Have the medicine container available if you can do so safely.
Call emergency services now if the person:
If they are not breathing normally, begin cardiopulmonary resuscitation if you know how and follow the emergency call handler's instructions.
And for anyone, someone who:
New breathing difficulty, fainting, severe confusion, hallucinations, or seizures require urgent reassessment.
Routine follow-up is appropriate after the immediate poisoning has been treated.
Arrange follow-up for continuing tiredness, medication dependence, withdrawal symptoms, anxiety, or concerns about future safety.
And for anyone, someone who:
The article also says
Do not leave the person alone.
Do not give food, drink, coffee, charcoal, or another medicine.
Do not make them vomit.
If they are unconscious but breathing, place them on their side if it is safe to do so.
Every sign above is quoted from the sofidex article on Meprobamate overdose. If you are not sure, err upward — it is always reasonable to be checked.