Which of the following is a sign of stimulant overdose?

Rapid heartbeat is a hallmark sign of stimulant overdose. Stimulants, such as amphetamines or cocaine, increase the levels of certain neurotransmitters in the brain, particularly norepinephrine and dopamine. This increase can lead to symptoms such as tachycardia (an abnormally rapid heart rate), hypertension, and palpitation, as the body is pushed into a state of heightened arousal and activity.

In the case of stimulant overdose, the positive inotropic and chronotropic effects on the heart result in an increased heart rate, which can be life-threatening if not managed promptly. While anxiety can occur with stimulant use or overdose, it does not specifically indicate overdose as it can also be present in normal usage or withdrawal syndromes. Respiratory distress could certainly be a severe complication but is not the most distinctive or common sign associated with stimulant overdoses compared to cardiovascular effects. Increased appetite is typically a characteristic of withdrawal rather than overdose, since stimulants usually suppress appetite during their action.

Thus, the presence of rapid heartbeat is a clear and distinctive sign that aligns with the physiological effects of stimulant overdose, highlighting the importance of monitoring cardiovascular status in individuals suspected of having taken excessive amounts of these substances.