Pharmacology Drug Classification: Sympathomimetics

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Questions and Answers

What is the #1 indicator to give a sympathomimetic bronchodilator?

Wheezing

Sympathomimetic is also known as?

Front Door Bronchodilator

What is the difference between Chronotrope and Inotrope?

Chronotrope affects heart rate; Inotrope affects contractility.

Positive Chronotrope means + = HR and - = HR.

Increase, Decrease Signup and view all the answers

What is the best order of drug classes to give a bronchodilator?

1st = Sympathomimetic, 2nd = Parasympatholytic, 3rd = Xanthines Signup and view all the answers

Positive Inotrope means + = Contractility and - = Contractility.

Increase, Decrease Signup and view all the answers

What are sympathomimetic medications used for?

Increase rate and contractility of heart (B1), Increase blood pressure (Alpha), Reverse airflow obstruction or bronchodilation (B2) Signup and view all the answers

Explain Beta 1 Receptors.

Found in heart (myocardium tissue); stimulation increases rate and strength; blockage decreases rate and strength. Signup and view all the answers

Explain Beta 2 Receptors.

Found in smooth muscle (SNS); stimulation causes dilation; blockage causes constriction. Signup and view all the answers

Explain Alpha 1 Receptors.

Found in blood vessels (SNS); stimulation causes constriction; blockage causes dilation. Signup and view all the answers

What is the difference between USABA, SABA, LABA?

USABA = Rescue/Reliever (< 3 hours), SABA = Rescue/Reliever (4-6 hours), LABA = Controller (12 or more hours) Signup and view all the answers

Sympathomimetic stimulates what receptors?

Alpha, Beta 1, Beta 2 Signup and view all the answers

What does USABA mean?

Ultra Short Acting Beta Agonist Signup and view all the answers

What does SABA mean?

Short Acting Beta Agonist Signup and view all the answers

What does LABA mean?

Long Acting Beta Agonist Signup and view all the answers

Why would you NOT use a LABA on an asthma attack?

It takes longer to work, but works for a longer period of time, so it is not a rescue medication. Signup and view all the answers

What is the most commonly used rescue medication?

SABA (Short Acting Beta Agonist) Signup and view all the answers

What does HAD mean?

Hyper Reactive Airway Disease Signup and view all the answers

What is the purpose of a bronchodilator?

Relax smooth muscle, Reverse or improve airflow obstruction (FEV1, SGAW) Signup and view all the answers

What lung disease are bronchodilators used for?

Asthma (HAD), Acute and Chronic Bronchitis, Emphysema, (CF) Cystic Fibrosis Signup and view all the answers

What does SGAW mean?

Specific Airway Conductance Signup and view all the answers

What is the purpose and difference between FEV1 and SGAW?

To see if reversible airway obstruction occurs after giving a bronchodilator; FEV1 = ↑ 12% or more, SGAW = ↑ 30% or more Signup and view all the answers

What is the difference between Adrenergic and Cholinergic?

Adrenergic = (NE) Norepinephrine, Cholinergic = (ACH) Acetylcholine Signup and view all the answers

All sympathomimetic drugs are?

Catecholamine (Chemical Structure) Signup and view all the answers

What are the two types of Catecholamines?

Pure Catecholamine (A, B1) and Catecholamine Derivatives (B2) Signup and view all the answers

If the enzyme (cAMP) cyclic (3-5) adenosine monophosphate increases, what happens?

Smooth muscle relaxes Signup and view all the answers

All Catecholamines have what?

Catechol nucleus (benzene ring) and amine side chain Signup and view all the answers

What is the difference between Pure Catecholamines (USABA) and Catecholamine Derivatives (SABA/LABA)?

Pure Catecholamines are strong (Alpha, Beta 1) and weak (Beta 2); Hydroxyl groups on C3 and C4; Quick onset with short duration (USABA). Catecholamine Derivatives are strong (Beta 2) and weak (Alpha, Beta 1); Hydroxyl groups on C3 and C5; Longer duration of action (SABA/LABA). Signup and view all the answers

What air sound would be a general indicator for the use of Racemic Epinephrine?

Mild/Moderate Stridor Signup and view all the answers

The longer an amine side chain is the more specific it is to what receptor?

Beta 2 Signup and view all the answers

What two enzymes inactivate Pure Catecholamines (NE)?

(COMT) Catechol-O-methyltransferase and (MAO) Monoamine Oxidase Signup and view all the answers

Study Notes

Sympathomimetic Bronchodilators

Wheezing is the primary indicator for administering a sympathomimetic bronchodilator.
Known as "Front Door Bronchodilator," sympathomimetics are key in respiratory treatments.
Chronotropic agents affect heart rate, while inotropic agents influence contractility.

Chronotropic and Inotropic Differences

Positive chronotropes increase heart rate, whereas negative ones decrease it.
Positive inotropes enhance contractility, in contrast to negative inotropes which diminish contractility.

Bronchodilator Drug Classes

The sequence for bronchodilator administration is: sympathomimetics first, followed by parasympatholytics, then xanthines.
Sympathomimetic medications function by increasing heart rate and contractility (via B1 receptors), raising blood pressure (via alpha receptors), and promoting bronchodilation (via B2 receptors).

Receptor Functions

Beta 1 receptors, located in the myocardium, increase heart rate and strength when stimulated.
Beta 2 receptors are found in smooth muscle; stimulation leads to dilation and blockage results in constriction.
Alpha 1 receptors in blood vessels cause constriction upon stimulation and dilation when blocked.

Types of Beta Agonists

USABA (Ultra Short Acting Beta Agonist): effects last less than 3 hours.
SABA (Short Acting Beta Agonist): lasts 4-6 hours and is commonly used for rescue.
LABA (Long Acting Beta Agonist): duration exceeds 12 hours, not suitable for acute attacks due to slow onset.

Important Medication Facts

The most frequently used rescue medication is SABA.
Hyper Reactive Airway Disease (HAD) is a condition where bronchodilators are crucial.
Bronchodilators aim to relax smooth muscle and improve airflow obstruction, measured by FEV1 and SGAW parameters.

Lung Diseases Treated with Bronchodilators

Effective for asthma, acute and chronic bronchitis, emphysema, and cystic fibrosis (CF).

Measurement Terminology

FEV1 (Forced Expiratory Volume in 1 second) and SGAW (Specific Airway Conductants) are used to assess reversibility of airway obstruction post-bronchodilator.

Adrenergic vs. Cholinergic Mechanisms

Adrenergic pathways utilize norepinephrine (NE), while cholinergic pathways utilize acetylcholine (ACh).

Catecholamines

All sympathomimetic drugs are catecholamines, categorized as pure catecholamines (acting on A and B1 receptors) and catecholamine derivatives (acting on B2 receptors).
Increasing levels of cyclic adenosine monophosphate (cAMP) lead to smooth muscle relaxation.

Chemical Structure of Catecholamines

Catecholamines consist of a catechol nucleus (benzene ring) and an amine side chain.
Differences exist between pure catecholamines and derivatives in strength at various receptors and duration of action.

Specificity of Drug Action

Longer amine side chains correlate with greater specificity to beta 2 receptors.
Racemic epinephrine is indicated for mild to moderate stridor cases.

Enzyme Inactivation

Pure catecholamines (e.g., norepinephrine) are inactivated by catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO).

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Test your knowledge on sympathomimetic drug classifications with these flashcards. Learn about bronchodilators, their indications, and key differences between related terms. Perfect for pharmacology students or healthcare professionals looking to refresh their knowledge.