What are the signs and symptoms of a vasoconstrictor overdose?

• A. Respiratory depression
• B. CNS stimulation
• C. Cardiac arrest
• D. Vasodilation

Answer: (B)

A vasoconstrictor overdose is characterized primarily by CNS stimulation. This occurs because vasoconstrictors, such as epinephrine or norepinephrine, can lead to increased heart rate, elevated blood pressure, and heightened alertness. When there’s an overdose, the stimulation of the central nervous system can manifest as symptoms such as anxiety, tremors, restlessness, or convulsions.

This response results from the vasoconstrictors interacting with adrenergic receptors in the brain, leading to an overactive state. It's essential for practitioners to recognize these signs, as they may indicate the need for corrective measures to manage the overdose effectively.

In contrast, while respiratory depression and cardiac arrest might occur in severe cases of toxicity or in the presence of other complications, they are not typical signs of vasoconstrictor overdose itself. Vasodilation is contradictory to the effects of vasoconstrictors, as these agents are intended to narrow blood vessels and increase blood pressure. Understanding these nuances is critical for safe administration and monitoring during procedures involving local anesthesia with vasoconstrictors.