What is a contraindication for the use of nitroglycerin according to REMAC?

The use of nitroglycerin is contraindicated in patients who have used phosphodiesterase-5 inhibitors, such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra), within the last 24 to 48 hours. This combination can lead to severe hypotension because both nitroglycerin and phosphodiesterase-5 inhibitors cause vasodilation. When used together, they can cause an excessive drop in blood pressure that could be life-threatening.

Understanding the pharmacological interactions is essential for paramedics. Phosphodiesterase-5 inhibitors enhance the effects of nitric oxide, and when nitroglycerin is administered to these patients, it amplifies this vasodilatory effect, leading to significant cardiovascular risks.

The other options do not represent absolute contraindications for the use of nitroglycerin. A history of asthma is typically not an issue, as nitroglycerin does not have adverse effects directly related to asthma. Severe dehydration might raise concerns about blood volume and perfusion status but does not specifically contraindicate nitroglycerin use. Similarly, age itself does not present a contraindication; the primary considerations involve overall health, co-morbid conditions, and medication interactions like those seen