Airway Pharmacology: Overview and Practice Questions

Airway pharmacology is a type of therapy that involves delivering aerosol medications to the respiratory tract in the lungs. This is important for the diagnosis and treatment of patients with pulmonary diseases.

We created this study guide to help you better understand the different types of drugs that are commonly administered in the field of respiratory care. We provided helpful practice questions on this topic for your benefit as well.

Types of Orally Inhaled Aerosol Drug Classes:

Here is a list of the most common types of aerosolized drugs that are administered in respiratory care:

• β-agonist bronchodilators
• Anticholinergic (anti-muscarinic) bronchodilators
• Mucolytic agents
• Corticosteroids
• Nonsteroidal anti-asthma drugs
• Anti-infective agents
• Inhaled pulmonary vasodilators

We’ve covered each drug class individually in more detail in separate study guides. You can use the links above to learn more about each individual class of medication.

Beta-2 Adrenergic Bronchodilators

Beta-2 adrenergic bronchodilators are a class of drugs that cause the smooth muscles of the airways to relax. This explains why they are effective in treating conditions that cause acute bronchospasm.

Anticholinergic Bronchodilators

Anticholinergic bronchodilators act on the parasympathetic nervous system and block the mechanism of action of the neurotransmitter acetylcholine (ACh). This promotes the relaxation of the smooth muscle tissue in the airways of the lungs.

Both β-agonists and anticholinergic agents are used to treat patients with obstructive conditions such as asthma, chronic bronchitis, and COPD.

Mucolytic Agents

Mucolytic agents are a class of drugs that help control copious amounts of thick secretions that are common in respiratory diseases. They are often administered to treat patients with conditions such as cystic fibrosis and bronchiectasis.

Inhaled Corticosteroids

Inhaled corticosteroids are a class of drugs that have anti-inflammatory effects on the airways. They are considered to be maintenance medications because they work by decreasing inflammation seen in obstructive diseases.

However, this type of medication should not to be used during an acute attack or exacerbation because they do not provide immediate relief.

Nonsteroidal Anti-Asthma Agents

Nonsteroidal anti-asthma agents are a class of drugs that are administered for the prophylactic management of asthma.

In other words, these drugs are also controller medications that should not be administered during an acute asthma attack because they do not provide immediate relief.

Anti-Infective Agents

Anti-Infective agents are a class of drugs that work to inhibit the spread of infections by eliminating potentially harmful organisms.

This includes antiviral, anti-fungal, and antituberculosis agents.

Inhaled Pulmonary Vasodilators

Inhaled pulmonary vasodilators are a class of aerosol drugs that are administered to treat pulmonary hypertension.

The most common type is iNO, which stands for inhaled nitric oxide.

Airway Pharmacology Practice Questions:

1. What are the adverse effects of inhaled corticosteroids?
Systemic adverse effects: adrenal Insufficiency, extrapulmonary allergies, acute asthma, HPA suppression, growth retardation, and osteoporosis. Local adverse effects: oropharyngeal fungal infections, dysphonia, cough, and bronchoconstriction.

2. What are the common inhaled corticosteroid brand names?
Azmacort, Flovent, Pulmicort, Advair, and Symbicort

3. What are the side effects of nonsteroidal anti-asthma drugs?
Cromolyn-like: none; Antileukotrienes: headache, dyspepsia, and liver enzyme elevation; Monoclonal Antibodies: injection site reaction and viral infections

4. What are some adverse effects of using adrenergic bronchodilators?
CFC induced bronchospasm, dizziness, hypokalemia, loss of bronchoprotection, nausea, tachyphylaxis, worsening ventilation/perfusion ratio, and a decrease in PaO2

5. What are some common side effects of using adrenergic bronchodilators?
Tremor, headache, insomnia, and nervousness

7. What are some examples of inhaled anti-infective agents?
Pentamidine isethionate (Nebupent), ribavirin (Virazole), tobramycin (TOBI), and zanamivir (Relenza)

8. What are the four advantages of using inhaled aerosols?
(1) Aerosol doses are smaller than systemic doses, (2) The onset of drug action is rapid, (3) Delivery is targeted to the organ requiring treatment, and (4) Systemic effects are often fewer and less severe

9. What are the indications for dornase alfa?
It is used to treat patients with cystic fibrosis and aims to reduce the frequency of infections while improving pulmonary function.

10. What are the indications for inhaled corticosteroids?
They are used for the anti-inflammatory maintenance of asthma and COPD.

11. What are the indications for long-acting (maintenance) agents?
They are used for the maintenance and control of bronchospasm and other symptoms of asthma and COPD.

12. What are the indications for nonsteroidal anti-asthma drugs?
They are used to manage mild to severe persistent asthma and as an alternative to steroidal treatments. They do not provide any benefits for acute asthma episodes.

13. What are the indications for racemic epinephrine?
It is recommended for strong α-adrenergic vasoconstriction effects and is used after extubation. It can also be used to treat epiglottitis, croup, or bronchiolitis, and it is administered to help control airway bleeding during an endoscopy.

14. What are the indications for short-acting (rescue) agents?
They are used for immediate relief of acute reversible airflow obstruction caused by asthma or other obstructive airway diseases.

15. What are the indications for using anticholinergic drugs?
They are used for the maintenance of COPD.

16. What are the indications for using combined anticholinergic and β-agonist bronchodilator drugs?
They are used for COPD patients to provide relief for an airflow obstruction. They are also useful in patients with severe asthma that have not responded well to β-agonist drugs.

17. What are the most common devices used to administer respiratory drugs?
MDI (metered-dose inhaler), SVN (small volume nebulizer), and DPI (dry powder inhaler)

18. What are the three phases of drug action?
Drug administration, pharmacokinetic, and pharmacodynamic

19. What are the three types of nonsteroidal anti-asthma drugs?
Cromolyn-like agents (Cromolyn sodium, Nedocromil sodium), antiLeukotrienes (Zarfirlukast, Zileuton), monoclonal antibodies or anti-IgE agents (Omalizumab).

20. What are the two inhaled vasodilators?
(1) Nitric Oxide (INOmax), which is used for the treatment of neonates with hypoxic respiratory failure, and (2) Iloprost (Ventavis), which is used for the treatment of pulmonary hypertension

22. What does a β1-receptor do?
It causes an increased heart rate and myocardial contractility.

23. What does a β2-receptor do?
It relaxes bronchial smooth muscle, stimulates mucociliary activity, and has some inhibitory action on the release of inflammatory mediators.

24. What is a fully ionized drug?
A drug that is not absorbed across a lipid membrane (e.g., Atrovent)

25. What is a muscarinic drug?
A drug that stimulates ACh receptors, specifically at the parasympathetic nerve-ending sites

26. What is the difference between an agonist and an antagonist?
Agonists are the stimulating agents, while antagonists are the blocking agents.

27. What is an isomer?
Isomers are compounds with the same molecular formula but different structural formulas that compare to the structures of albuterol and levalbuterol.

28. What are sympathetic and parasympathetic receptors?
Sympathetic = adrenergic; Parasympathetic = cholinergic

29. What is a prodrug?
A drug that is not active until it is metabolized

30. What is Combivent?
A medication combination of ipratropium bromide and albuterol

31. What is DuoNeb, and what is its proper dose?
Ipratropium Bromide 0.5 mg and Albuterol 2.5 mg, administered with an SVN

32. When should an inhaled corticosteroid be administered during an asthma attack?
This drug class should not be given during an acute asthma attack because it does not provide short-term relief. Inhaled corticosteroids are maintenance medications.

33. What is the brand name for acetylcysteine?
Mucomyst

34. What is the brand name for dornase alfa?
Pulmozyme

35. What is the brand name for ipratropium bromide?
Atrovent

36. What is the brand name for tiotropium bromide?
Spiriva

37. What is the drug administration phase?
It describes the method by which a drug dose is made available to the body.

38. What is the mode of action for cromolyn sodium?
It inhibits the degranulation of mast cells, which prevents the release of histamine and other mediators of inflammation.

39. What is the mode of action for inhaled corticosteroids?
They are lipid-soluble drugs that act on intracellular receptors. The full effect takes multiple hours; therefore, they do not provide instant relief.

40. What is the pharmacodynamic phase?
Describes the mechanism by which a drug molecule causes its effects

41. What is the pharmacokinetic phase?
It describes the time, course, and disposition of a drug in the body.

42. What should a patient know about inhaled corticosteroids?
They are not to be used as a rescue drug.

43. Why is it recommended to administer albuterol with Mucomyst?
Mucomyst is known to cause bronchospasm; therefore, a bronchodilator is needed.

44. What is the most common route of drug administration for a pulmonary patient?
Aerosol therapy

45. What are the advantages of inhaled aerosols?
You can use smaller doses compared to the systemic route; the onset of the drug is rapid; the delivery is targeted to the specific organ needing treatment; and there are fewer systemic side effects

46. What are the disadvantages of inhaled aerosols?
There are more variables that can affect the delivered dose, and there is often a lack of knowledge of device performance by the patient and caregiver.

47. Inhaled bronchoactive aerosols are intended for local effects in the airway, but some undesired systemic effects can result from what?
From the absorption and distribution throughout the body

48. What is the difference between a fully ionized aerosol drug and a non-ionized aerosol drug?
A fully ionized drug has little or no systemic side effects (it is not absorbed across lipid membranes). A non-ionized drug does produce systemic side effects (it is lipid-soluble and diffuses across cell membranes into the bloodstream).

49. What is the L/T ratio?
Lung availability/total systemic availability; quantifies the efficiency of an aerosol drug in the lungs

50. Using the L/T ratio, which aerosol delivery method is more efficient?
MDI (46%) works slightly better than DPI (23%)

51. What are drug effects caused by?
The combination of a drug with a matching receptor

52. What is the usual neurotransmitter in the parasympathetic system?
Acetylcholine

53. What do adrenergic drugs help directly dilate?
The bronchial tree

54. Cholinergic causes what?
Bronchoconstriction

55. What are the indications for short-acting adrenergic agents?
They are rescue drugs that are good for approximately four hours and are used to provide relief for an acute airflow obstruction.

56. What are the indications for long-acting adrenergic agents?
They are drugs that will last approximately 12 hours and are used for the maintenance of obstructive lung diseases.

57. What is the most common use of adrenergic bronchodilators?
To improve the airflow in patients with asthma

58. What happens during beta-1-receptor stimulation?
It causes an increase in heart rate and myocardial contractility.

59. What happens during beta-2-receptor stimulation?
It relaxes bronchial smooth muscle tissue, stimulates mucociliary activity, and has some inhibitory action on the release of inflammatory mediators.

60. Why would you choose Xopenex over albuterol?
Xopenex is indicated over albuterol in patients with tachycardia.

61. What is the most common side effect of beta-2 selective agents?
Tremors

62. How can you evaluate a patient’s response to bronchodilator therapy?
By using pre and post-bronchodilator studies; ABG and pulse oximetry; blood glucose and potassium; and blood pressure

63. What are the two inhaled anticholinergic bronchodilators?
Ipratropium and tiotropium

64. What is combined anticholinergic and beta-agonist indicated for?
Ipratropium bromide and albuterol (DuoNeb) are indicated for the treatment of patients with COPD or asthma.

65. What are the side effects of anticholinergic aerosol agents?
Cough and dry mouth

66. What are the two mucus-controlling agents?
N-acetylcysteine (MucoMyst) and dornase alfa

67. How is N-acetylcysteine administered?
Either by nebulization or direct tracheal installation

68. How does N-acetylcysteine work?
It breaks down the disulfide bonds of the mucus so that the patient can cough it up more easily.

69. What can N-acetylcysteine cause?
It can cause bronchospasm, which is why it should never be given without a bronchodilator.

70. What type of patients are treated with dornase alfa?
Cystic fibrosis

71. What is the mode of action of dornase alfa?
It breaks down protein bonds.

72. What is another name for dornase alfa?
Pulmozyme

73. What is the mode of action of inhaled corticosteroids?
They act on intracellular receptors.

74. What are the three types of drugs that prevent asthma from happening?
(1) Cromolyn sodium, (2) Antileukotrienes, and (3) Monoclonal antibodies or anti-IgE agents

75. What are the indications for nonsteroidal anti-asthma drugs?
They are indicated for the prophylactic management of asthma and offer no benefit for treating an acute airway obstruction.

76. What is pentamadine isethionate?
It is used to treat pneumonia caused by pneumocystis jiroveci, which is seen in patients with AIDS.

77. What is ribavirin?
It is a drug used to treat respiratory syncytial virus (RSV) using a SPAG generator.

78. What is inhaled tobramycin?
It is a drug used to fight pseudomonas aeruginosa in patients with cystic fibrosis.

79. What is inhaled zanamivir?
It is a drug that is used to treat influenza.

80. What is nitric oxide used for?
It is used for the treatment of pulmonary hypertension.

81. The acting length of a bronchodilator refers to what?
It refers to how long the drug lasts.

82. What should be performed before and after the administration of a bronchodilator?
You should test the patient with a peak flow meter before and after administering a breathing treatment to check if the drug was effective.

83. What are three subgroups of adrenergic bronchodilators?
(1) Ultra-short catecholamine agents, (2) Short-acting non-catecholamine agents, and (3) Long-acting adrenergic bronchodilators

84. What is the major risk of administering a bronchodilator?
The major risk is an increased heart rate. If it increases by more than 20 beats/min, you should stop the treatment and notify the physician.

85. What is the speed of onset for inhaled aerosol drugs?
The onset is rapid.

Final Thoughts

It goes without saying that each respiratory therapist (and student) must learn and understand the different classes of inhaled aerosol medications. Otherwise, how would it be possible to treat and provide care for patients with a pulmonary condition?

That is why the topic of airway pharmacology is so important.

Hopefully, the information in this study guide can help make the learning process easier for you. We have a similar guide on aerosol drug therapy that I think will be beneficial for you. Thanks for reading and, as always, breathe easy, my friend.