Final answer:
The nurse should expect headache as an adverse effect of sublingual nitroglycerin, which is a vasodilator used for angina treatment.
Step-by-step explanation:
The nurse should expect headache as an adverse effect of sublingual nitroglycerin. Nitroglycerin is a vasodilator that helps to relieve angina by relaxing the smooth muscles of the coronary arteries, which increases blood flow and oxygen to the heart muscle. However, the mechanism that allows nitroglycerin to be effective also causes dilation of other blood vessels, leading to a common side effect: headache. This occurs due to the sudden increase in blood flow and a decrease in blood pressure, which can cause headaches. Other common side effects may include dizziness and flushing, but among the options provided, headache is the most relevant.