Adrenergic

Definition

Adrenergic drugs are sympathomimetic agents that mimic the effects of norepinephrine and epinephrine on alpha and beta receptors, producing fight-or-flight responses such as increased heart rate, vasoconstriction, bronchodilation, and elevated blood pressure.

Receptor Effects

• Alpha-1: Vasoconstriction, increased BP (phenylephrine).
• Beta-1: Increased heart rate and contractility (dobutamine).
• Beta-2: Bronchodilation, uterine relaxation (albuterol, terbutaline).

Common Medications

Epinephrine (anaphylaxis, cardiac arrest), norepinephrine (septic shock), dopamine (shock), albuterol (asthma/COPD), phenylephrine (hypotension, nasal decongestion).

Nursing Considerations

Monitor heart rate, blood pressure, rhythm, and blood glucose (adrenergics raise glucose). Assess IV sites frequently for extravasation. Vasopressors can cause tissue necrosis; phentolamine is the antidote. Educate asthma patients to rinse the mouth after inhaled corticosteroids and use beta-2 agonists as rescue, not maintenance.

NCLEX Relevance

High-yield for pharmacology side effects, especially tachycardia, hypertension, tremors, and hyperglycemia. Differentiate adrenergic agonists from antagonists (beta-blockers).