What is the maximum epinephrine dose for a cardiac patient?

• A. 0.04 mg
• B. 0.2 mg
• C. 0.4 mg
• D. 1.0 mg

Answer: (A)

The main idea is safety: for patients with cardiac disease, the total amount of epinephrine used in local anesthesia must be kept very small to avoid stressing the heart. Epinephrine increases heart rate, contractility, and blood pressure, which raises myocardial oxygen demand. In a heart that’s already compromised, that extra workload can precipitate ischemia or arrhythmias. Because of this, clinicians cap the total epinephrine dose far below what a healthy patient can tolerate. With typical dental anesthetic preparations, this conservative limit is reached after only a small amount of drug, so using more would cross the safety threshold. That explains why the smallest dose option is the best choice for a cardiac patient.