Adrenergic Agonists & Antagonists Pharmacology Flashcards

Vocabulary flashcards covering adrenergic receptors, mechanisms, prototype agonist and antagonist drugs, and key clinical/nursing considerations based on class lecture notes.

Adrenergic Agonist

A drug that stimulates an adrenergic receptor and produces a sympathetic-like response.

Adrenergic Antagonist

A drug that blocks an adrenergic receptor and prevents its normal sympathetic response.

$\alpha_1$ Adrenergic Receptor

An adrenergic receptor located primarily in smooth muscle (blood vessels, mucous membranes, bladder, pupils, uterus, GI tract) whose activation causes contraction, vasoconstriction, and pupil dilation.

$\alpha_2$ Adrenergic Receptor

An adrenergic receptor located primarily in the central nervous system (CNS) whose activation decreases sympathetic outflow and CNS stimulation, resulting in reduced blood pressure, reduced heart rate, and sedation.

$\beta_1$ Adrenergic Receptor

An adrenergic receptor located primarily in the heart and kidneys whose activation increases heart rate, force of contraction, electrical conduction, and renin release.

$\beta_2$ Adrenergic Receptor

An adrenergic receptor located primarily in the bronchioles/lungs, blood vessels, GI tract, uterus, and liver whose activation causes smooth muscle relaxation and bronchodilation.

Positive Chronotropic Effect

An increase in heart rate caused by $\beta_1$ receptor activation.

Positive Inotropic Effect

An increase in the force of cardiac contraction caused by $\beta_1$ receptor activation.

Positive Dromotropic Effect

An increase in the speed of electrical conduction through the heart caused by $\beta_1$ receptor activation.

Phenylephrine

An $\alpha_1$ adrenergic agonist that causes vasoconstriction; used primarily to treat nasal congestion and reduce swelling of mucous membranes.

Tamsulosin

An $\alpha_1$ adrenergic antagonist that relaxes smooth muscle in the bladder and prostate to decrease resistance to urine flow.

Prazosin

An $\alpha_1$ adrenergic antagonist that causes vasodilation to decrease blood pressure.

Clonidine

An $\alpha_2$ adrenergic agonist that decreases sympathetic and CNS outflow; used to treat hypertension, ADHD, and for sedation-related purposes.

Dobutamine

A $\beta_1$ adrenergic agonist that increases heart rate, contractility, and conduction; used primarily in acute heart failure and shock.

Metoprolol

A selective $\beta_1$ adrenergic antagonist (beta-blocker) that decreases heart rate, force of contraction, and blood pressure; used for hypertension, chest pain, and fast heart rates.

Albuterol

A $\beta_2$ adrenergic agonist that relaxes bronchiolar smooth muscle to produce bronchodilation; used for asthma and COPD.

Propranolol

A nonselective beta-blocker that blocks both $\beta_1$ and $\beta_2$ receptors, decreasing heart rate and blood pressure while posing a risk of bronchoconstriction in patients with asthma or COPD.

Adrenergic Receptor G-Protein Signaling Mechanisms

The intracellular mechanisms where $\alpha_1$ couples with $G_q \rightarrow \uparrow \text{IP}_3/\text{DAG} \rightarrow \uparrow \text{Ca}^{2+}$, $\alpha_2$ couples with $G_i \rightarrow \downarrow \text{cAMP}$, and $\beta_1$ and $\beta_2$ couple with $G_s \rightarrow \uparrow \text{cAMP}$.