Which emergency condition can be caused by overdosing on a sedative?

Respiratory depression is the correct answer because an overdose of a sedative can significantly depress the central nervous system, leading to diminished respiratory drive. Sedatives like benzodiazepines or barbiturates can relax the muscles involved in breathing, reduce the brain's ability to stimulate breathing, and may result in inadequate oxygen exchange. This can lead to hypoxia or even respiratory failure if not promptly addressed.

In contrast, while hypertension can occur due to various physiological stress responses or drug interactions, it is not directly a result of sedative overdose. Severe allergic reactions, although potentially life-threatening, are typically related to exposure to allergens rather than sedatives. Cardiac arrest can occur as a severe consequence of multiple factors, including respiratory depression, but it is not the primary effect directly attributable to sedative overdoses. Understanding the effects of sedatives on the respiratory system is essential for recognizing and managing this critical emergency effectively.