Which medication could potentially cause severe tissue damage if extravasated?

Norepinephrine is the correct answer because it is a potent vasoconstrictor. When norepinephrine is administered intravenously, it is crucial that it stays within the vein. If it extravasates, which is the leakage of the drug into surrounding tissues, it can lead to severe vasoconstriction and subsequent ischemia in those areas. This can result in tissue necrosis and damage due to reduced blood flow and oxygen delivery.

In contrast, the other medications listed typically do not cause tissue damage through extravasation. Nitroglycerin, for example, is a vasodilator that, while potentially causing localized irritation, does not typically result in severe tissue injury. Metoprolol, a beta-blocker, and amlodipine, a calcium channel blocker, are less likely to cause complications related to extravasation since they do not exert strong vasoconstrictive effects in the same manner as norepinephrine. Therefore, norepinephrine stands out as the drug with a significant risk of causing severe tissue damage if it leaks out of the vascular system during administration.