Oops! You got it wrong...
EXPLANATION
✔Correct answer:
Rise from sitting or lying positions gradually. Nitrates, such as nitroglycerin, are potent vasodilators used to treat angina by relaxing vascular smooth muscle. This vasodilation affects both veins and arteries, leading to decreased venous return (preload) and reduced systemic vascular resistance (afterload), ultimately lowering myocardial oxygen demand. However, this systemic vasodilation can also cause a significant drop in blood pressure, particularly when changing positions quickly from lying or sitting to standing. This effect is known as orthostatic (or postural) hypotension. Instructing the patient to rise slowly allows the cardiovascular system time to compensate for the positional change, reducing the risk of dizziness, lightheadedness, syncope, and potential falls. This is a very common side effect and managing it is crucial for patient safety.
Nitrates increase nitric oxide (NO) in vascular smooth muscle cells. NO activates guanylate cyclase, increasing cyclic guanosine monophosphate (cGMP) levels. Elevated cGMP leads to dephosphorylation of myosin light chains, causing smooth muscle relaxation and vasodilation. Venous dilation reduces preload, while arterial dilation reduces afterload. The generalized vasodilation can lead to pooling of blood in the lower extremities upon standing, causing a transient decrease in blood pressure (orthostatic hypotension).
Think of your blood vessels like flexible hoses. Nitrates make these hoses wider and more relaxed. When you suddenly stand up, gravity pulls blood down into the widened "hoses" in your legs. If you stand up too fast, not enough blood gets back to your brain quickly, making you feel dizzy – like water pressure dropping momentarily in a wide hose. Getting up slowly gives the system time to adjust the pressure.
Nurses should educate patients taking nitrates about recognizing and managing common side effects, especially orthostatic hypotension. Key teaching points include:
- Advise the patient to change positions slowly, especially when getting out of bed or rising from a chair. Suggest dangling legs over the side of the bed for a few minutes before standing.
- Instruct the patient to sit or lie down immediately if they feel dizzy or lightheaded.
- Teach the patient about other common side effects like headache (often managed with acetaminophen) and flushing.
- Reinforce the correct administration technique for the specific nitrate formulation (e.g., sublingual, transdermal patch, sustained-release tablet) and storage instructions (e.g., keeping sublingual tablets in their original dark container).
- Warn patients to avoid alcohol and other medications that can cause hypotension (e.g., sildenafil, tadalafil) while taking nitrates, as this can exacerbate the hypotensive effect.
✘Incorrect answer options:
Monitor your pulse once per day. While nitrates can sometimes cause reflex tachycardia (an increase in heart rate) as the body tries to compensate for the drop in blood pressure, monitoring the pulse only once daily is unlikely to capture this potentially transient effect effectively. Furthermore, orthostatic hypotension (addressed by rising slowly) is generally considered a more common and immediately concerning side effect requiring specific preventative action (avoiding falls) than reflex tachycardia for most patients initiating therapy.
Cut back on your sodium intake. Reducing sodium intake is important for managing conditions like hypertension and heart failure, which often coexist with angina. However, it is not a direct strategy for managing the acute side effects of nitrate therapy, such as orthostatic hypotension or headache. Sodium restriction helps manage fluid volume and long-term blood pressure control, rather than the immediate hemodynamic effects of vasodilation caused by nitrates.
Chew your sustained-release nitrate tablets. This instruction is dangerous and incorrect. Sustained-release (SR) or extended-release (ER) formulations are designed to release the medication gradually over several hours. Chewing or crushing these tablets would disrupt the release mechanism, leading to a rapid absorption of a large dose. This could cause severe hypotension, potentially leading to syncope, shock, or even death. Patients must be explicitly taught to swallow sustained-release tablets whole.
References
- Lilley, L. L., Rainforth Collins, S., & Snyder, J. S. (2023). Pharmacology and the Nursing Process (10th ed.). Elsevier.
- Urden, L. D., Stacy, K. M., & Lough, M. E. (2021). Priorities in Critical Care Nursing (9th ed.). Elsevier.