CHAPTER 14 RESPIRATORY MEDICATIONS
PRETEST QUESTIONS
1. With which of the following lung disorders would acetylcysteine (Mucomyst) be indicated?
2. A patient with glottic edema after extubation is in mild respiratory distress. Which of the following medications would be of benefit in this situation?
3. You are having difficulty intubating a combative patient in the emergency department. The respiratory therapist should recommend the delivery of which drug to facilitate intubation?
4. Which of the following airway disorders may be successfully treated with dexamethasone (Decadron)?
REVIEW
I. CLASSIFICATION OF RESPIRATORY MEDICATIONS
CRT Exam Content Matrix: IIIC3,IIID5a, IIIF2h4, IIIG2b, IIIG4a,b,c,e-k
RRT Exam Content Matrix: IIIC3, IIID5a, IIIG2b, IIIG4b-h
b. Used to dilute secretions for improved expectoration. Often instilled through ET tubes and tracheostomy tubes, 3 to 5 mL at a time.
c. Often used with bronchodilating agents because a common side effect of acetylcysteine is bronchospasm.
a. Used most commonly in patients with cystic fibrosis or other lung conditions in which thick, tenacious sputum is present
Exam Note
These medications stimulate one or more of the following adrenergic receptors.
| Receptor | Location | Response |
|---|---|---|
| Alpha | Mucosal blood vessels, bronchial smooth muscle | Vasoconstriction, bronchoconstriction |
| Beta1 | Heart muscle | Increased heart rate and cardiac output, arrhythmias |
| Beta2 | Bronchial smooth muscle, peripheral mucosal blood vessels, CNS, and peripheral limb muscles | Bronchodilation, vasodilation, nervousness (CNS), tingling in fingers |
Exam Notec. Used to decrease mucosal edema and inflammation after extubation or in pediatric patients with croup
b. Chemically similar to albuterol. The (R)-enantiomer of albuterol, which has the most bronchodilating effects, was isolated and purified for use and called levalbuterol.
a. It is a long-acting beta agonist with stronger beta2 than beta1 effects and is available as a DPI preparation used twice daily.
a. It is a long-acting beta agonist with stronger beta2 than beta1 effects and is available as a DPI preparation used twice a day.
c. Duration of action is 12 h with a peak effect at 30 to 60 min compared with 3 to 5 h for salmeterol.
a. It is a long-acting beta agonist with stronger beta2 than beta1 effects and is available as a liquid aerosolized preparation used twice a day with a small volume nebulizer.
a. An anticholinergic drug; it blocks the cholinergic constricting influences on the airway and potentiates the adrenergic influences (beta2 stimulation), resulting in bronchodilation.
Exam Note
Ipratropium bromide is faster acting, longer lasting, and exhibits fewer side effects than atropine.
b. Peak effect of the drug is 1 to 2 h (compared with 15 min to 1 h with beta agonists with a duration of action of 3 to 4 h).
c. Used to decrease airway resistance, especially in patients with asthma, bronchitis, and emphysema. Some studies have shown ipratropium to be a more potent bronchodilator than beta-adrenergic agents for the treatment of emphysema and bronchitis.
e. Dosage: 0.5 mg in nebulized solution or two inhalations (36 µg) from a metered-dose inhaler four times daily. Current literature shows that up to 10 puffs four times a day is safe.
E. Phosphodiesterase Inhibitors: These drugs are called xanthines, and they inhibit the cellular production of phosphodiesterase, an enzyme that readily breaks down cyclic adenosine monophosphate (AMP), another cellular enzyme, which, when produced, results in bronchodilation. It is by the increased production of cyclic AMP that sympathomimetic bronchodilators work.
a. Stimulates respiratory rate and depth of breathing and produces pulmonary vasodilation and bronchodilation
e. Dosage: IV loading dose, 6 mg/kg of body weight; maintenance dose, 0.5 mg/kg/h (average dose is 250 mg every 6 h)
(3) Produces pulmonary vasodilation, reducing pulmonary hypertension that results from chronic hypoxemia
(4) Stimulates breathing by altering the hypoxic response curve when PaO2 is elevated above 60 mm Hg
Exam Notea. Stabilizes the mast cell, making it less sensitive to specific antigens and inhibiting the release of histamine
Exam Note
Exam Notea. During an asthma attack, mast cells in the airway release leukotrienes, which results in an inflammatory response. This response includes bronchoconstriction, mucus production, and vascular permeability. These drugs inhibit the response of the leukotrienes, preventing the inflammatory response from occurring.
c. Common drugs of this type are zafirlukast (Accolate), montelukast (Singulair), and zileuton (Zyflo). Zafirlukast and montelukast are referred to as leukotriene receptor antagonists because they block the receptor sites of leukotrienes. Zileuton is referred to as a leukotriene inhibitor because it inhibits the release of leukotrienes.
d. These drugs are administered as an oral tablet. Zafirlukast is administered twice daily, montelukast once daily, and zileuton four times a day.
a. An antifoaming agent (surfactant) used to decrease the surface tension of frothy, bubbly secretions that are observed with pulmonary edema
b. Used in the treatment of pulmonary edema to disperse the edematous bubbles, making the airway more patent. (Not commonly administered clinically but sometimes appears on the NBRC exams.)
a. A depolarizing agent that competes with acetylcholine for cholinergic receptors of the motor end plate of a muscle. If these receptors remain occupied by the depolarizing agent, further stimulation cannot occur and paralysis persists.
Atropine may be administered to counteract these effects.a. A nondepolarizing agent (related to curare) that blocks the transmission of acetylcholine at the postjunctional membrane.
Pancuronium bromide does not cause the release of histamine as curare does; therefore, bronchospasm is not a complication.
Exam Noteb. The indications, onset of action, and side effects are similar to pancuronium, although vecuronium has a shorter duration time of 60 to 90 min.
b. The indications are the same as the other nondepolarizing drugs, but rocuronium has a shorter time of onset of only 1 to 2 min. The duration of action is 30 to 60 min.
Exam Note
Exam Noted. The nebulizer used to deliver pentamidine should incorporate a one-way valve that directs the patient’s exhaled air through a scavenging filter to prevent contaminating the personnel and surrounding air with this agent.
b. Used specifically to treat RSV in neonatal and pediatric patients (declining use in the clinical setting)
d. The medication is delivered continuously for 12 to 18 h per day for 3 days to 1 wk, generally through an oxygen hood, oxygen tent, or face tent.
(3) Occlusion of ET tube or ventilator tubing by the hygroscopic particles. Particle filters may decrease the potential of this hazard.
I. Corticosteroids (Aerosolized): These antiinflammatory agents are used in respiratory care to prevent or reduce airway inflammation in asthma and upper airway swelling that accompanies glottic edema. Administering these agents via aerosol (usually MDI) reduces systemic side effects, such as cushingoid symptoms (edema, moon face) and adrenal suppression.
Exam Note
Exam NoteJ. Combination Drugs: These drugs provide the combined effects of bronchodilation and antiinflammatory responses.
c. Morphine, codeine, and meperidine (Demerol) are examples of narcotic analgesics; morphine is the most potent. Morphine and meperidine are strong respiratory suppressants. Codeine has a relatively low respiratory suppressant effect.
a. These drugs are not related chemically to the narcotic analgesics and relieve mild to moderate pain without the loss of consciousness.
c. The most commonly used nonnarcotic analgesics used are the salicylates, which include aspirin. Aspirin is classified as a nonsteroidal antiinflammatory drug (NSAID). Because it also reduces fever, it may help reduce respiratory distress in critically ill patients with a limited pulmonary reserve.
d. Aspirin also has anticoagulation properties and is used therapeutically in thromboembolitic diseases.
e. Other NSAIDs include ibuprofen, which is the most commonly prescribed NSAID for musculoskeletal conditions, because of fewer GI tract side effects, and indomethacin, which is used most commonly to treat pericardial and pleural inflammation. Indomethacin is also used in neonates to help close a patent ductus arteriosus (PDA).
1. The most commonly used sedative drugs are those classified as benzodiazepines. These drugs have sedative and antianxiety effects. They have replaced barbiturates because they produce fewer side effects and have fewer drug interactions and less potential for addiction.
2. These drugs are most commonly used as antianxiety agents and generally do not cause significant respiratory or cardiovascular depression.
3. One of the most common sedatives used is midazolam (Versed), which is often used to provide short-term conscious sedation and relaxation during invasive procedures such as a bronchoscopy. It also has amnesia effects.
4. Another common antianxiety drug that has a longer duration of action than midazolam is diazepam (Valium).
1. These drugs stimulate urine production and are frequently used in the ICU to promote loss of excess water and salt. Fluid overload can be the result of CHF or large amounts of fluid given IV during resuscitation efforts.
2. The most common type of diuretic is what is classified as a loop diuretic. These drugs block the reabsorption of sodium in the ascending loop of Henle. This results in the excretion of sodium and water. The most commonly used loop diuretic is furosemide (Lasix).
3. This type of diuretic is potent and is used over short periods of time. They effectively treat hypertension, pulmonary edema, and peripheral edema.
4. Diuretic use may lead to metabolic alkalosis as evidenced by the elevated bicarbonate level and decreased chloride level. Hypokalemia (decreased potassium) and hypomagnesemia (low magnesium) may also occur, especially with the loop diuretics.
5. Another type of diuretic is the osmotic diuretic, for example, mannitol (Osmitrol), which is used to treat oliguria (little urine formation) or anuria (no urine formation) as well as cerebral edema.
CRT Exam Content Matrix: IIA22, IIID5b
RRT Exam Content Matrix: IIID5b
B. DPIs are breath activated and create aerosol by drawing air through a dose of powdered medication. Because DPIs are breath activated, they reduce the problem of the patient having to coordinate inspiration with actuation of the device.
C. High inspiratory flows are required to generate the aerosol; therefore, DPIs are not indicated for acute bronchospasm or in weak, elderly patients or patients younger than 6 years.
D. The powdered medication is in a capsule that is placed in the inhaler. By adjusting the inhaler, the patient punctures the capsule, which allows the powder to be administered as the patient inhales.
CRT Exam Content Matrix: IIIG4k
RRT Exam Content Matrix: IIIG4h
A. Influenza vaccine is recommended annually for the following who are either at high risk of contracting influenza or in close contact with people at higher risk
2. This bacteria is the leading cause of illness in young children and can cause illness and even death among the elderly and people who have underlying medical conditions.
3. Individuals who are at increased risk of pneumococcal infection and who should be vaccinated include
Exam Note
POSTCHAPTER STUDY QUESTIONS
1. What is the primary indication for acetylcysteine?
2. What is racemic epinephrine most commonly used for?
3. List four examples of sympathomimetic bronchodilators.
4. List two examples of parasympatholytic bronchodilators.
5. Which neuromuscular blocking agent is used primarily for short-term paralysis during a difficult intubation?
6. How does cromolyn sodium help in the treatment of asthma?
7. List five antibiotics that are aerosolized and the conditions for which they are indicated.
8. List three corticosteroids that are commonly aerosolized.
9. List the side effects of corticosteroid therapy.
10. List three leukotriene modifiers.
11. Leukotriene modifiers are administered for what purpose?
Bills G, Soderberg R. Principles of pharmacology for respiratory care, ed 2. Albany, NY: Delmar; 1998.
Oakes D. Clinical practitioner’s pocket guide to respiratory care, ed 5. Rockville, MD: Health Educator; 1996.
Rau J. Respiratory care pharmacology, ed 7. St Louis: Mosby; 2008.
Wilkins RL, Stoller JK, Kacmarek R. Egan’s fundamentals of respiratory care, ed 9. St Louis: Mosby; 2009.
