In which condition is nitroglycerin typically contraindicated?

Nitroglycerin is a common medication used to treat chest pain (angina) and heart-related conditions by dilating blood vessels and improving blood flow to the heart. However, it is particularly contraindicated in hypotension, meaning it should not be administered when blood pressure is low.

The reason for this contraindication is that nitroglycerin further lowers blood pressure by relaxing the vascular smooth muscle. For a patient with hypotension, this can lead to dangerously low blood pressure levels, which may result in inadequate perfusion to vital organs and can potentially lead to shock.

Understanding the other conditions: hypertension is not a direct contraindication because, while nitroglycerin lowers blood pressure, it is often used to manage hypertensive crises under careful monitoring. Severe allergies do not typically interact adversely with nitroglycerin; instead, individual patient sensitivities should be monitored. Heart failure can complicate the use of nitroglycerin, but it is not an absolute contraindication as it can be used judiciously with considerations of the patient's volume status.