Sympathetic Nervous System Medications

Flashcards covering the Sympathetic Nervous System, Adrenergic Drugs, Catecholamines, and Adrenergic Blocking Drugs.

Sympathetic Nervous System

"Fight or flight" response control.

Adrenergic Drugs

Also called sympathomimetics, produce effects similar to the sympathetic nervous system.

Direct-acting Adrenergic Drugs

Produce effect by directly stimulating the receptor site (e.g., epinephrine, norepinephrine, isoproterenol).

Indirect-acting Adrenergic Drugs

Release endogenous norepinephrine which then stimulates the receptor (e.g., amphetamine).

Dual-acting Adrenergic Drugs

Either directly stimulate the receptor or release endogenous norepinephrine (e.g., ephedrine and Pseudoephedrine).

Catecholamines - CNS Effects

Produce CNS excitation or alertness; higher doses can cause anxiety, restlessness, and tremors.

Catecholamines - Cardiovascular Effects

Increase the force and rate of contraction of the heart; increase blood pressure and total peripheral resistance.

Catecholamines - Eye Effects

Lower intraocular pressure and can cause mydriasis.

Catecholamines - Respiratory System Effects

Cause a relaxation of bronchiole smooth muscles.

Catecholamines

Can be natural or synthetic and include Dobutamine, Dopamine, Epinephrine, Norepinephrine, Isoproterenol.

Catecholamines - Pharmacokinetics

Widely distributed, predominantly metabolized by the liver, excreted primarily in the urine.

Alpha Receptor Stimulation (Catecholamines)

Used to treat hypotension.

Beta1-Receptor Stimulation (Catecholamines)

Used to treat bradycardia, heart block, low cardiac output.

Beta2-Receptor Stimulation (Catecholamines)

Used to treat acute and chronic bronchial asthma, emphysema, bronchitis.

Adrenergic Drug Interactions/Adverse Reactions

Can be serious, including hypertension, arrhythmias, anxiety, tremors, tachycardia, seizures, Hyperglycemia.

Adrenergic Blocking Drugs

Sympatholytic drugs that disrupt SNS function by blocking impulse transmission at adrenergic receptor sites; classified as Alpha- or Beta-adrenergic Blockers.

Alpha-Adrenergic Blockers - MOA

Block the synthesis, storage, release, and uptake of norepinephrine by neurons; antagonize epinephrine and norepinephrine at alpha receptor sites.

Alpha-Adrenergic Blockers - Effects

Relaxation of smooth muscle in the blood vessels, increased dilation of blood vessels, and decreased blood pressure.

Alpha₁ Antagonists Examples

prazosin (Minipress®), doxazosin (Cardura®), phentolamine (Regitine®)

Alpha-Adrenergic Blockers - Therapeutic Uses

Treat hypertension, peripheral vascular disorders, and benign prostatic hypertrophy.

Alpha-Adrenergic Blockers - Adverse Reactions

Severe hypotension.

Selective beta1-blockers

Reduce stimulation of the heart (also called cardioselective beta-adrenergic blockers) E.g Metoprolol, Atenolol, Bisoprolol & Esmolol

Nonselective beta1 and beta2-blockers

Not only reduce stimulation of the heart but can also cause the bronchioles of the lungs to constrict E.g Propranolol, nadolol and carteolol

Mixed alpha and beta blockers

e.g. Labetalol & Carvedilol

Beta Antagonists (Β Blockers)

Frequently used, lower blood pressure.

Beta-Adrenergic Blockers - Therapeutic Uses

Used to treat heart attacks, angina, hypertension, supraventricular arrhythmias, anxiety, migraine headaches, and open-angle glaucoma.

Beta-Adrenergic Blockers - Adverse Reactions

Cardiac and respiratory depression, arrhythmia, severe Bronchospasm, severe hypotension.