Which class of medication may enhance the hypotensive effects of nitrates?

Calcium channel blockers are known to enhance the hypotensive effects of nitrates, making them the correct choice in this scenario. Nitrates work by dilating blood vessels, which can lower blood pressure. Calcium channel blockers also have vasodilatory effects; they inhibit calcium from entering the cells of the heart and blood vessel walls, leading to further relaxation of the vascular smooth muscle and a decrease in blood pressure. When these two classes of medications are used together, their actions can be synergistic, resulting in a more pronounced hypotensive effect compared to using either medication alone.

The other classes mentioned do not significantly contribute to the hypotensive effects of nitrates in the same way. Antidepressants may influence blood pressure but are not typically used specifically for enhancing the effects of nitrates. Anticoagulants focus on preventing blood clot formation without directly affecting blood pressure. Antibiotics are primarily used to treat infections and do not have a direct effect on blood pressure regulation or enhancement of nitrate actions. Thus, calcium channel blockers stand out as the most relevant and appropriate choice in this context.