If a PDE-5 inhibitor has been taken within the last 24-48 hours, should you administer nitroglycerin?

If a PDE-5 inhibitor has been taken within the last 24-48 hours, should you administer nitroglycerin?

• A. Yes; no issue
• B. Only with certain formulations
• C. It depends on chest pain severity
• D. No; nitroglycerin is contraindicated with recent PDE-5 inhibitor use

Answer: (D)

The key idea is that nitroglycerin and PDE-5 inhibitors can interact to cause dangerous hypotension. PDE-5 inhibitors (such as sildenafil, tadalafil, and vardenafil) block the breakdown of cGMP, so they enhance nitric oxide–mediated vasodilation. Nitroglycerin also increases nitric oxide activity and cGMP. When both are present within a short window (roughly 24–48 hours, depending on the specific PDE-5 inhibitor), their effects add up and can drop blood pressure to dangerously low levels. Because of this risk, nitroglycerin should not be given if a PDE-5 inhibitor has been used recently. Manage chest pain with other appropriate measures and monitor vital signs; nitrates may be reconsidered only after enough time has passed since PDE-5 inhibitor use.

The key idea is that nitroglycerin and PDE-5 inhibitors can interact to cause dangerous hypotension. PDE-5 inhibitors (such as sildenafil, tadalafil, and vardenafil) block the breakdown of cGMP, so they enhance nitric oxide–mediated vasodilation. Nitroglycerin also increases nitric oxide activity and cGMP. When both are present within a short window (roughly 24–48 hours, depending on the specific PDE-5 inhibitor), their effects add up and can drop blood pressure to dangerously low levels.

Because of this risk, nitroglycerin should not be given if a PDE-5 inhibitor has been used recently. Manage chest pain with other appropriate measures and monitor vital signs; nitrates may be reconsidered only after enough time has passed since PDE-5 inhibitor use.