Final answer:
When a patient who has overdosed vomits and is experiencing gurgling as they try to breathe, the immediate action you should take is to suction the airway.
Step-by-step explanation:
When a patient who has overdosed vomits and is experiencing gurgling as they try to breathe, the immediate action you should take is to suction the airway. This is important because the vomit can obstruct the airway and lead to further respiratory distress. By suctioning the airway, you can remove any remaining vomit and ensure that the patient's airway is clear.