Which first aid measure should be prioritized in cases of suspected overdose?

In cases of a suspected overdose, ensuring the airway is clear is critical because an obstructed airway can lead to respiratory failure and can be life-threatening. Many overdose situations may result in a decreased level of consciousness, which increases the risk of airway compromise due to the patient's inability to protect their own airway or manage their breathing effectively.

Clearing the airway allows for proper ventilation and oxygenation, which are essential for survival while further interventions are considered, such as administering medication or calling emergency services. This first aid measure takes precedence over others because even if other actions, such as providing medication or psychological support, are crucial, they cannot be effective if the patient is unable to breathe adequately due to an obstructed airway.

Monitoring vital signs, while important, is secondary to taking immediate action to secure the airway, as vital signs alone do not address the underlying danger of potential asphyxiation.