What is the definition or description of: hydrocodone overdose?

Hydrocodone overdose: An overdose occurs when an excessive / dangerous dose of a drug / substance is used. O/D symptoms may include: Pinpoint pupils, Constipation, Nausea, Spasms (pain) of the stomach or intestinal tract, Vomiting, Low blood pressure, Weak pulse, Coma (unresponsiveness), Drowsiness, Possible seizures, Difficulty breathing, Slow breathing that requires more effort, Shallow breathing, No breathing"