Toxicity from which of the following medications may cause a patient to see a green-yellow halo around lights?

Choice A rationale:

Increased afterload refers to the resistance against which the heart must pump to eject blood into the aorta. While increased afterload can contribute to chest pain in certain conditions like aortic stenosis, it's not the primary cause of angina.

Angina is typically triggered by exertion or emotional stress, which increase myocardial oxygen demand. Increased afterload doesn't directly cause this imbalance in oxygen supply and demand, making it less likely to be the primary driver of angina pain.

Choice B rationale:

Inadequate myocardial oxygenation is a key concept in understanding angina, but it's not the most precise answer to the patient's question about the cause of their pain.

It's important to explain the underlying reason for the inadequate oxygenation, which is coronary artery disease.

Choice C rationale:

Coronary artery disease (CAD) is the most common cause of angina. It's characterized by narrowing or blockage of the coronary arteries, which supply oxygen-rich blood to the heart muscle.

When the heart's demand for oxygen exceeds the supply available through the narrowed arteries, it experiences ischemia (lack of oxygen), leading to the characteristic chest pain of angina.

This explanation directly addresses the patient's question about the cause of their pain, linking the symptom to the underlying disease process. Choice D rationale:

Increased preload refers to the amount of blood filling the ventricles before they contract. While increased preload can contribute to heart failure and pulmonary edema, it's not typically a direct cause of angina.

Choice A rationale:

Drowsiness and blurred vision are not common adverse effects of nitroglycerin.

While some individuals may experience mild drowsiness, it's not a primary concern.

Blurred vision is not typically associated with nitroglycerin use.

Choice B rationale:

Nervousness and paresthesia (tingling or numbness in the extremities) are not common adverse effects of nitroglycerin.

Some individuals may experience transient anxiety or nervousness, but it's not a characteristic side effect.

Paresthesia is more commonly associated with other medications or conditions.

Choice C rationale:

Throbbing headache and dizziness are the most common adverse effects of nitroglycerin.

They occur due to nitroglycerin's vasodilatory effect, which causes blood vessels to relax and widen.

This can lead to a temporary drop in blood pressure, resulting in headaches and dizziness.

The headaches are often described as throbbing or pulsating, and they typically occur in the frontal or temporal regions of the head.

Dizziness may be mild or severe, and it may be accompanied by lightheadedness or a feeling of unsteadiness.

Choice D rationale:

Tinnitus (ringing in the ears) and diplopia (double vision) are not common adverse effects of nitroglycerin.

They may occur in rare cases, but they are not typically associated with its use.