For certain prescribed medications, the EMT's role is to assist the patient in self-administration rather than to give the drug directly. Before doing so, the EMT must confirm that the medication is prescribed to that patient, that it is the correct drug for the current symptoms, and that it has not expired. The three classic patient-assist medications are sublingual nitroglycerin for chest pain, an epinephrine auto-injector for anaphylaxis, and a metered-dose inhaler (MDI) such as albuterol for bronchospasm.
Nitroglycerin is indicated for suspected cardiac chest pain or angina in a patient with a prescription and adequate blood pressure. The typical dose is 0.4 mg, delivered as one sublingual tablet or spray, repeated up to three times at five-minute intervals per protocol. Its mechanism is vasodilation, particularly of venous vessels, reducing cardiac preload and myocardial oxygen demand while dilating coronary arteries. Blood pressure must be reassessed before each dose, and nitroglycerin is withheld if the systolic pressure is generally below 100 to 110 mmHg, depending on protocol. Other contraindications include recent use of a phosphodiesterase inhibitor such as sildenafil within 24 to 48 hours, suspected right ventricular or inferior wall infarction, head injury, or increased intracranial pressure, because the combination can cause severe, profound hypotension. Common side effects include headache, dizziness, flushing, and hypotension, so patients should be seated or supine after administration. Nitroglycerin tablets must be stored in their original dark glass container, away from light, heat, and moisture, and a burning or tingling sensation under the tongue indicates the tablet is still potent.
Epinephrine auto-injectors such as EpiPen, Auvi-Q, and Adrenaclick are first-line, time-critical treatments for anaphylaxis. The adult dose is 0.3 mg intramuscular and the pediatric dose (EpiPen Jr) is 0.15 mg, delivered to the lateral mid-thigh and held in place for about 3 to 10 seconds. Most devices can be used through light clothing. Epinephrine is a sympathomimetic adrenergic agonist that produces vasoconstriction, bronchodilation, and increased cardiac output, reversing the airway swelling, bronchospasm, and hypotension of anaphylaxis. Because delay increases the risk of airway obstruction and cardiovascular collapse, there are no absolute contraindications in true anaphylaxis. Common side effects include tachycardia, anxiety, tremors, and palpitations. Effects are short-lived, typically 10 to 20 minutes, so a second dose may be needed if symptoms persist or recur, after which the EMT continues monitoring the ABCs and transports promptly. The used auto-injector should accompany the patient to the hospital, with the time of administration documented.
Albuterol delivered via metered-dose inhaler or nebulizer is indicated for bronchospasm and wheezing associated with asthma or COPD. The typical MDI dose is 1 to 2 puffs, about 90 mcg per puff, repeated per protocol, often every 5 to 20 minutes. As a short-acting beta-2 agonist, albuterol relaxes bronchial smooth muscle to produce bronchodilation, with an onset of action of roughly 5 minutes. The EMT should coach the patient to exhale fully, seal the lips around the mouthpiece, inhale deeply while pressing the canister, and hold the breath for about 10 seconds; shaking the canister first ensures the medication is evenly mixed. A spacer can improve delivery for patients with poor coordination. Side effects include tachycardia, tremors, nervousness, and palpitations. Albuterol should not be assisted without a patient prescription or explicit protocol authorization.