Name a contraindication for using epinephrine with local anesthetics.

Using epinephrine with local anesthetics can pose significant risks, especially in patients with uncontrolled hyperthyroidism. This condition can lead to an increased sensitivity to catecholamines, which are substances like epinephrine that can exacerbate symptoms such as tachycardia, hypertension, and even potential cardiac arrhythmias. In individuals with uncontrolled hyperthyroidism, administering epinephrine may promote these cardiovascular effects, making it a contraindication for use in such patients.

In contrast, the other conditions listed, such as high cholesterol, controlled asthma, or minor hypertension, do not present the same immediate risks when combined with epinephrine. Patients with controlled asthma may often tolerate epinephrine, as it is sometimes used as a bronchodilator in emergencies. Patients with high cholesterol or minor hypertension typically have other risk factors managed and might not experience serious adverse effects from epinephrine. Therefore, the significant concern with uncontrolled hyperthyroidism makes it a clear contraindication for the use of epinephrine in local anesthetics.