Nursing care
Epinephrine: what to check before you give it
Written and reviewed by Dana Whitfield, RN, MSN · 4 min read · Updated September 2026
Short answer
Epinephrine's dose and route change with the emergency it treats: 1 mg IV every three to five minutes in cardiac arrest, but 0.3 mg intramuscular in anaphylaxis. Giving the cardiac arrest dose IV for anaphylaxis, or the reverse, is a dangerous and commonly tested error. Route and concentration are the whole question.
What it does and why it is prescribed
Epinephrine is a nonselective adrenergic agonist acting on alpha and beta receptors. Alpha stimulation drives vasoconstriction and raises blood pressure; beta-1 stimulation increases heart rate and contractility; beta-2 stimulation relaxes bronchial smooth muscle. One drug, three effects, and each indication leans on a different one of them.
In cardiac arrest, the goal is the alpha-mediated vasoconstriction that improves coronary and cerebral perfusion pressure during CPR. In anaphylaxis, the goal is the combination of vasoconstriction to counter distributive shock, bronchodilation to relieve airway obstruction, and reduced mediator release from mast cells. Same drug, but the indication decides the dose, the route, and how urgently it must reach the bloodstream.
Nursing considerations before giving it
Confirm the concentration before drawing up the dose. Cardiac arrest uses 1 mg of the 1:10,000 concentration given IV push every three to five minutes per ACLS protocol. Anaphylaxis uses 0.3 to 0.5 mg of the 1:1,000 concentration given intramuscularly, typically into the anterolateral thigh, repeated every five to fifteen minutes if symptoms persist.
Mixing these up is the error the exam is built around and the error that kills in practice: giving the 1:1,000 concentration IV, or giving the IV cardiac-arrest dose IM, causes serious harm. In cardiac arrest, epinephrine is given as part of the resuscitation algorithm alongside compressions and defibrillation, never as a substitute for either. In anaphylaxis, IM administration into the thigh has faster and more reliable absorption than deltoid or subcutaneous injection.
What to monitor
Continuous cardiac monitoring is required whenever epinephrine is given, since it can provoke tachyarrhythmias, ventricular ectopy, or a sharp rise in blood pressure. In cardiac arrest, monitor rhythm changes on the defibrillator pads and end-tidal CO2 if capnography is in use, as a rising value suggests improving perfusion during CPR.
In anaphylaxis, reassess airway patency, work of breathing, stridor, wheeze, and blood pressure within five minutes of the IM dose, because a second dose may be needed quickly if symptoms have not improved. Track for biphasic reaction, a recurrence of anaphylaxis hours after apparent resolution, which is why observation typically continues for four to six hours or longer after the initial episode resolves.
Side effects versus adverse effects
Expected side effects at therapeutic dosing include anxiety, tremor, palpitations, pallor, and a pounding headache, all consequences of the same adrenergic stimulation that makes the drug work. These are uncomfortable but do not by themselves mean the dose was wrong or that the drug should be withheld.
Adverse effects that demand escalation include chest pain suggesting myocardial ischaemia, sustained hypertension risking intracranial haemorrhage, ventricular arrhythmia, and pulmonary oedema. The line between an expected side effect and a dangerous adverse effect is often severity and duration: a brief tremor is expected, chest pain of any duration is not.
What to hold for and when to call
In cardiac arrest there is no scenario where epinephrine is withheld once indicated; the emergency itself overrides relative cautions like hypertension or cardiac disease. Continue per protocol and call for additional support if arrhythmia worsens rather than pausing the drug.
In non-arrest settings, relative caution applies in patients with severe hypertension, known coronary artery disease, or hyperthyroidism, but anaphylaxis is a life-threatening exception where these cautions do not justify withholding the drug. Call the provider immediately for chest pain, a sustained systolic pressure that keeps climbing, new arrhythmia on the monitor, or any sign the anaphylaxis is progressing despite an appropriately dosed and repeated IM injection.
Patient teaching
Patients discharged with an auto-injector need to know it delivers the IM anaphylaxis dose into the outer thigh, through clothing if necessary, and that it should be used at the first sign of a severe reaction rather than delayed to see if symptoms worsen. Teach them to call emergency services immediately after use, even if symptoms improve, because a second reaction can follow the first.
Teach them to carry two doses when prescribed, since roughly one in three anaphylactic reactions needs a repeat injection, and to check the expiry date and the colour of the solution periodically, since discoloured epinephrine has degraded and should be replaced. Family members and caregivers should be shown the injection technique, not just told about it, before the patient leaves the facility.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our pharmacology practice questions are the closest set to what this page covers.
One question from the pharmacology set
A client with heart failure is started on furosemide 40 mg PO daily. Which findings should the nurse report to the provider before administering the next dose? Select all that apply.
Rationale
Furosemide is a loop diuretic, so the two things you are watching are potassium and kidney function. A potassium of 2.9 mEq/L is below the 3.5–5.0 reference range and puts the client at risk for dysrhythmia — hold and report. Muscle cramps with palpitations are the clinical face of that same hypokalemia, so they are reported together, not separately. A creatinine that doubles signals the diuresis has outrun renal perfusion. A blood pressure of 132/78 and a 1 kg loss are the expected response to the drug working, not reasons to hold it.
Answer: A, D, E
Common questions
What is the epinephrine dose for cardiac arrest?
1 mg of the 1:10,000 concentration given IV push, repeated every three to five minutes according to ACLS protocol, alongside ongoing CPR and defibrillation as indicated.
What is the epinephrine dose for anaphylaxis?
0.3 to 0.5 mg of the 1:1,000 concentration given intramuscularly into the anterolateral thigh, repeated every five to fifteen minutes if symptoms have not resolved.
Why does the route matter so much with epinephrine?
The two common concentrations, 1:1,000 and 1:10,000, are dosed for different routes and different emergencies. Giving the wrong concentration by the wrong route can cause dangerous overdose or an ineffective, too-slow response.
Is a second epinephrine auto-injector dose normal?
Yes. A meaningful proportion of anaphylactic reactions require a second dose, which is why patients are typically prescribed two auto-injectors and taught to use the second if symptoms persist or return.
What does biphasic anaphylaxis mean for monitoring?
It means symptoms can return hours after the initial reaction appears resolved. Patients are usually observed for several hours after treatment rather than discharged immediately once symptoms settle.
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