Nitroglycerin (NTG) is a common medication used in emergency settings to treat chest pain that may indicate a cardiac issue, such as angina or a heart attack. NTG works by widening blood vessels, which reduces the heart’s workload and increases blood flow to the heart muscle. When a person calls 911, Emergency Medical Technicians (EMTs) are often the first providers to arrive. Whether an EMT can administer NTG depends entirely on their specific level of training and the protocols established by their local medical director and state regulations.
Differentiating Provider Levels and Authorization
Pre-hospital emergency care is structured in a tiered system, where a provider’s certification level dictates their scope of practice and authorized medications. A standard EMT, sometimes referred to as an EMT-Basic, generally operates at the Basic Life Support (BLS) level. These providers are not authorized to carry nitroglycerin to administer to a patient, as their scope is limited to non-invasive procedures and assisting with select patient-prescribed medications. Advanced EMTs (AEMTs) and Paramedics operate at higher levels of certification that include Advanced Life Support (ALS) skills. These providers operate under protocols that allow them to administer nitroglycerin directly from the ambulance’s drug box, often as a 0.4 milligram sublingual tablet or metered spray.
Authorization for all levels of providers is contingent upon state licensing laws and specific local medical director protocols. These protocols provide the legal framework for when and how a medication can be used in the field. Consequently, what an EMT can do in one region may be different from what an EMT can do in another, even within the same state.
Assisting Patients Versus Administering Medication
For the EMT-Basic, the distinction between “assisting” and “administering” is a legal and practical difference concerning nitroglycerin. Assisting means the EMT helps the patient take a medication previously prescribed by a physician and currently in the patient’s possession. The EMT-Basic is trained to retrieve the patient’s own NTG, confirm the prescription is current, and then help the patient take the dose, usually a sublingual tablet or spray. This is permitted because the medication is already prescribed to the patient, and the EMT’s role is to facilitate self-administration under controlled circumstances. The patient must be alert and able to indicate their desire to take the medication for this assistance to occur.
In contrast, “administering” means the provider is initiating the use of a medication supplied from the ambulance’s stock, under standing orders or direct order from a medical control physician. This ability to initiate and administer NTG is restricted to the higher-level AEMTs and Paramedics. This distinction explains why a Basic EMT can be involved in a patient receiving NTG without being licensed to carry the drug themselves.
Safety Checks and Contraindications for Nitroglycerin Use
Regardless of the provider’s certification level, safety checks must be performed before nitroglycerin is given to a patient with chest discomfort. The most important initial step is to confirm the patient is experiencing symptoms consistent with a possible cardiac event, such as chest pain or pressure. Nitroglycerin is a potent vasodilator, meaning it widens blood vessels, which can cause a sudden and significant drop in blood pressure. Because of this effect, the provider must confirm a blood pressure reading above a specific systolic threshold, usually set at 90 to 100 millimeters of mercury (mmHg) by most protocols. If the patient’s blood pressure is too low, giving NTG could lead to severe hypotension, potentially causing the patient to lose consciousness or experience cardiovascular collapse.
A contraindication that must be screened for is the recent use of phosphodiesterase-5 (PDE5) inhibitors, such as sildenafil (Viagra) or tadalafil (Cialis). When combined with nitroglycerin, these drugs create a synergistic effect that can cause an uncontrolled, life-threatening drop in blood pressure. Protocols require providers to ask if the patient has taken a short-acting PDE5 inhibitor within the last 24 hours or a long-acting one within the last 48 hours. Once administered, the patient’s vital signs, especially blood pressure and pain level, must be monitored. Protocols permit the dose to be repeated up to a total of three doses, including any the patient may have taken before the EMT arrived, provided the blood pressure remains above the safe threshold after each dose.