Which substance can interact with nitrates to enhance hypotensive effects?

Nitrates are commonly used in the treatment of angina as they work primarily by dilating blood vessels, which helps to reduce the heart's workload and improve blood flow to the heart muscle. One of the significant side effects of nitrates can be hypotension, or lower than normal blood pressure.

Alcohol is known to potentiate the hypotensive effects of nitrates. When taken together, alcohol can enhance the vasodilatory effects of nitrates, leading to a greater drop in blood pressure than would occur with either substance alone. This interaction can significantly increase the risk of side effects such as dizziness, lightheadedness, and falls due to the more pronounced hypotension.

In contrast, caffeine, nicotine, and acetaminophen do not have this effect. Caffeine is a stimulant that may raise blood pressure, nicotine can constrict blood vessels leading to elevated blood pressure, and acetaminophen generally does not have any significant effects on blood pressure or interact with nitrates in a way that would enhance hypotensive effects.