Nitroglycerin is a medication frequently prescribed to alleviate chest pain, known medically as angina, which often results from reduced blood flow to the heart muscle. This medication works by widening blood vessels, thereby improving blood supply and reducing the heart’s workload. Understanding the correct procedure for taking nitroglycerin is important for effective and safe management of angina.
Administering Nitroglycerin Sublingual Tablets
When experiencing chest pain, sit down immediately before taking nitroglycerin. This helps prevent dizziness or fainting that can occur as blood pressure may drop due to the medication’s effects. The tablet is designed for sublingual administration; place it directly under the tongue to dissolve and absorb rapidly into the bloodstream, bypassing the digestive system for quicker relief.
Allow the tablet to dissolve completely without chewing, crushing, or swallowing it, as this can affect its absorption and effectiveness. Saliva around the tablet aids in its dissolution; if your mouth is dry, a small sip of water beforehand can help. Following the first dose, wait for 5 minutes to assess if the chest pain improves.
If the chest pain persists or worsens after the initial 5-minute period, a second tablet can be taken. Wait another 5 minutes to see if relief occurs. Should the pain still be present after this second interval, a third tablet may be administered. Do not exceed three tablets within a 15-minute period.
Common Reactions and Side Effects
Nitroglycerin relieves chest pain by widening blood vessels (vasodilation), which can also cause physical reactions. A mild headache is a common and expected sign that the medication is working, resulting from expanded blood vessels. Similarly, facial flushing can occur as blood vessels near the surface dilate.
Dizziness or lightheadedness, particularly when moving from a sitting or lying position to standing, is another common reaction due to the blood pressure-lowering effect of nitroglycerin. Other less common side effects can include nausea, vomiting, or weakness. These effects typically indicate the medication is active and often subside as your body adjusts.
Managing these mild side effects often involves simple measures. If you experience dizziness or lightheadedness, remaining seated or lying down can help alleviate the sensation. Slowly rising from a seated or lying position can also mitigate these effects. Should headaches become bothersome, your doctor might suggest an over-the-counter pain reliever.
When to Call for Emergency Medical Help
Prompt action is necessary when chest pain does not subside. If your chest pain does not improve or worsens after taking the first nitroglycerin tablet, call for emergency medical help immediately. Even if some relief is felt, but pain returns or remains significant after the third tablet or after 15 minutes, contact emergency services immediately. Do not attempt to drive yourself to the hospital.
Beyond persistent chest pain, other signs warrant immediate medical attention. These include severe or persistent dizziness, fainting, vision changes like blurred vision, or difficulty breathing. A severe headache that does not ease or any new, concerning symptoms should also prompt an emergency call. Angina can sometimes be a precursor to a heart attack, so seek help quickly to reduce potential heart damage.
Crucial Safety Considerations
Nitroglycerin interacts dangerously with certain medications, particularly those used for erectile dysfunction, known as phosphodiesterase-5 (PDE5) inhibitors. Medications such as sildenafil, tadalafil, and vardenafil can cause a severe and potentially fatal drop in blood pressure when combined with nitroglycerin. Therefore, individuals taking nitroglycerin must never use these drugs. A waiting period of 24 to 48 hours is required after taking a PDE5 inhibitor before nitroglycerin can be safely administered.
Alcohol consumption can also intensify the blood pressure-lowering effects of nitroglycerin, increasing the risk of dizziness, lightheadedness, and fainting. It is advisable to limit or avoid alcohol while using nitroglycerin to prevent these additive effects. Discussing alcohol intake with a healthcare provider is always recommended.
Proper storage of nitroglycerin tablets is important for maintaining their potency. They should be kept in their original amber-colored glass bottle, tightly capped after each use, and stored away from light, heat, and moisture. Storing them in a cool, dry place at room temperature, typically between 20°–25°C (68°–77°F), helps preserve their effectiveness. Never transfer tablets to other containers, especially plastic ones, or mix them with other medications, as this can lead to loss of potency.
Once opened, nitroglycerin tablets have a limited shelf life; replace the bottle every 3 to 6 months, even if tablets remain, as they lose strength over time. Always check the expiration date on the bottle and replace expired medication. Carrying nitroglycerin at all times is advisable for individuals with angina, ensuring it is readily accessible in case of an attack.