Nitroglycerin is a common medication used to manage angina, a type of chest pain. Like all medications, nitroglycerin comes with an expiration date, which often raises questions about its continued safety and effectiveness once this date passes. Understanding the implications of using expired nitroglycerin is important for individuals who rely on this medication for their heart health.
Understanding Nitroglycerin’s Role
Nitroglycerin, also known as glyceryl trinitrate, is a type of nitrate medication primarily used to relieve and prevent angina. Angina pain occurs when the heart muscle does not receive enough oxygen-rich blood, often due to narrowed or blocked coronary arteries. Nitroglycerin addresses this by working as a vasodilator, meaning it relaxes and widens blood vessels throughout the body.
This vasodilation primarily affects veins, which reduces the amount of blood returning to the heart. This reduces the heart’s workload and oxygen demand, alleviating chest pain. Nitroglycerin also causes some dilation of coronary arteries, which can increase blood flow directly to the heart muscle. It converts into nitric oxide, signaling blood vessels to relax.
Why Nitroglycerin Loses Potency
Nitroglycerin is an unstable compound, susceptible to degradation over time. Its effectiveness diminishes due to environmental factors. Exposure to light, air, moisture, and heat can accelerate its chemical breakdown.
Degradation primarily leads to a loss of potency, not toxic compounds. It breaks down into less active substances. The expiration date guarantees the drug’s full strength and quality when stored correctly. After this date, the active ingredient may be reduced, making it less effective.
Nitroglycerin tablets are unstable; the active ingredient can evaporate if not stored properly. They should be kept in their original glass container, tightly capped, and protected from light and moisture. Cotton fillers, frequent opening, and warm storage (e.g., a pant pocket) can significantly reduce potency.
The Safety of Expired Nitroglycerin
Expired nitroglycerin is not considered dangerous or toxic. The primary concern is its potential lack of effectiveness. Since angina attacks are medical emergencies requiring prompt treatment, a medication with reduced potency may fail to alleviate symptoms.
If someone experiences an angina attack and relies on expired nitroglycerin, the medication may not work as intended, leading to continued chest pain and more serious complications. Rapid action is necessary to restore blood flow to the heart. Nitroglycerin degrades quickly and should not be used beyond its expiration date due to potential health consequences if ineffective.
What To Do With Expired Nitroglycerin
Individuals who have expired nitroglycerin should replace it immediately with a fresh supply. Maintaining an up-to-date medication is important for effective management of angina. Proper disposal of expired or unused medications is also necessary to prevent accidental ingestion or environmental contamination.
Dispose of expired nitroglycerin through a drug take-back program. Many communities offer these at pharmacies, police stations, or take-back events. Some pharmacies also provide mail-back envelopes.
If a take-back option is unavailable, dispose of it in household trash. Mix the medication with an unappealing substance like dirt, cat litter, or used coffee grounds. Place it in a sealed bag before trashing to prevent accidental consumption by people or pets.