What are the severe side effects of epinephrine?

The severe side effects of epinephrine, particularly concerning its role in treating severe allergic reactions and asthma, include abnormal cardiac rhythm and chest pain. Epinephrine is a potent adrenergic agonist that stimulates alpha and beta receptors in the body, leading to various cardiovascular effects. Its action can increase heart rate and contractility, which may result in abnormal heart rhythms known as arrhythmias. Additionally, the vasoconstrictive properties of epinephrine can lead to increased blood pressure and chest pain, especially in individuals with pre-existing heart conditions or those who receive an overdose.

The other options listed, while they may occur in some individuals, typically represent more mild and less critical side effects associated with epinephrine use. For example, nausea and dizziness can result from vasodilation and decreased perfusion; dry mouth and headache may arise from the drug's stimulant effects or adrenal response; and fatigue and insomnia can emerge from overstimulation of the nervous system. However, these side effects do not carry the same level of risk as abnormal cardiac rhythms and chest pain, highlighting the importance of monitoring patients closely when administering epinephrine, especially in emergency settings.