Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Elsewhere, use your local poison information service or emergency number.
Call emergency services now if the person:
Is difficult to wake, collapses, or loses consciousness
Has a seizure, severe confusion, or trouble breathing
Vomits blood or passes black, tar-like stools
Has severe or rapidly worsening abdominal pain
Has taken naproxen intentionally to cause self-harm
May have taken other dangerous medicines or substances
For routine follow-up after emergency assessment, contact the treating service if vomiting continues, urine output decreases, swelling develops, or stomach symptoms do not improve.
And for anyone, someone who:
is unconscious, or cannot be woken
you believe has taken an overdose or swallowed something poisonous
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
2
Does any of this apply?
Book an appointment
Attend any planned blood tests even if symptoms have settled.
And for anyone, someone who:
is having side effects from a medicine, or is struggling to take it as prescribed
The article also says
Get immediate poison-centre or medical advice for any suspected naproxen sodium overdose, even if there are no symptoms.
In the United States, Poison Help can be reached at 1-800-222-1222 .
Do not leave an unconscious or severely drowsy person alone.
Place them on their side if it is safe to do so, and do not give anything by mouth.
Do not drive yourself if you are drowsy, confused, or unwell.
Every sign above is quoted from the sofidex article on Naproxen sodium overdose. If you are not sure, err upward — it is always reasonable to be checked.