Pharmacology: Expectorant, Antitussive, Mucolytic, and Decongestant Therapy

Which drug undergoes metabolism to form cysteine, disulfides, and conjugates? a. Acetylcysteine b. Dextromethorphan c. Guaifenesin d. Pseudoephedrine

a Rationale: Acetylcysteine undergoes metabolism, and it forms cysteine, disulfides, and conjugates

Match the drug class with its anticipated action. Drug class: a. Expectorants b. Antitussives c. Mucolytics d. Decongestants Anticipated action: 1. Reduce viscosity of secretions to allow for ejection of mucus 2. Suppress harmful or nonproductive cough 3. Liquefies and loosens thick mucous secretions 4. Relieves nasal congestion

a = 1 b = 2 c = 3 d = 4

Which counseling points would a nurse provide a patient who has been prescribed an antitussive containing codeine? (Select all that apply.) a. Avoid alcohol while receiving the codeine-containing antitussive. b. Potential side effects include sedation, dizziness, nausea, vomiting, and constipation. c. Increase water intake to help loosen secretions for them to be coughed up. d. Report any changes in sputum or mucus color, chest tightness, or difficulty breathing to a health care provider. e. Avoid driving or other activities that require mental alertness in the event dizziness and sedation occur.

a, b, d, e Rationale: Patients who are taking codeine-containing antitussives should not consume alcohol because of the risk for central nervous system (CNS) depression/significant sedation. Sedation, dizziness, nausea, vomiting, and constipation are all potential side effects associated with codeine-containing antitussives. A patient should be educated to report any changes in the color of the sputum or mucus, chest tightness, or difficulty breathing to health care provider because this may signify the possibility of a more serious condition that warrants further evaluation and treatment. Because opioid -containing antitussives may cause significant dizziness and drowsiness, patients should be advised against driving or completing other activities requiring mental alertness in the event these side effects occur.

Which patients would a nurse determine can safely receive inhaled acetylcysteine? (Select all that apply.) a. A patient with diabetes b. A patient with asthma c. An older adult with a history of drug abuse d. A patient with benign prostatic hyperplasia e. An older adult with uncontrolled hypertension

a, c, d, e Rationale: There is no concern with administering acetylcysteine to a patient with diabetes. It is not expected to affect blood glucose levels. There is no concern with administering acetylcysteine to an older patient with history of drug abuse because there is no abuse potential. There is no concern with administering acetylcysteine to patient with benign prostatic hyperplasia. It is not expected to affect voiding abilities like decongestants and antitussives do. There is no concern with administering acetylcysteine to a patient with uncontrolled hypertension because it is not expected to increase blood pressure levels.

Which statements describe the pharmacokinetics of guaifenesin? (Select all that apply.) a. It is readily absorbed in the gastrointestinal tract. b. It is largely protein bound. c. The drug undergoes hydrolysis. d. Its metabolism extensively involves the cytochrome P450 system. e. Guaifenesin is excreted in urine.

a, c, e Rationale: Guaifenesin is readily absorbed in the gastrointestinal tract. Guaifenesin is metabolized through hydrolysis. The major route of elimination for guaifenesin is the urine.

Which instructions would nurse include when teaching a patient about the administration of guaifenesin? (Select all that apply.) a. Avoid alcohol while receiving guaifenesin. b. Limit use to 3 to 5 days to avoid rebound congestion. c. Increase water intake up to 3 L per day unless contraindicated. d. Contact a if health care provider if the product needs to be used longer than 2 weeks. e. Report a fever of 100.4°F (38°C) or higher or symptoms lasting longer than 3 to 4 days.

a, c, e Rationale: Patients receiving guaifenesin should avoid alcohol products while receiving therapy. To help liquefy and loosen secretions, patients should be advised to drink up to 3 L of water a day unless contraindicated (e.g., in the setting of fluid restriction such as heart failure). The patient should be advised to report a fever of 100.4°F (38°C) or higher or symptoms lasting longer than 3 to 4 days because this may indicate an infection that needs further evaluation.

A patient asks a nurse when he or she should expect to start experiencing the effects of pseudoephedrine. Which time frame would the nurse share? a. 5 to 10 minutes b. 15 to 30 minutes c. 3 to 4 hours d. 5 to 6 hours

b Rationale: A patient would likely begin to experience the effects of pseudoephedrine (i.e., onset of action) between 15 to 30 minutes after administration.

Which drug causes a nurse to carefully consider the patient's drug list for potential drug-drug interactions due to its metabolism through CYP450 2D6? a. Acetylcysteine b. Dextromethorphan c. Guaifenesin d. Pseudoephedrine

b Rationale: Dextromethorphan is metabolized by CYP450 2D6 and should be carefully considered with other drugs the patient may be taking such as paroxetine and fluoxetine.

Which clinical manifestation alerts a nurse to a possible drug-drug interaction in patient with Parkinson disease who developed the common cold and is receiving selegiline and pseudoephedrine? a. Hepatotoxicity b. Hypertension c. Muscle aches and cramps d. Renal dysfunction

b Rationale: Selegiline is an MAOI-B used in the management of Parkinson disease. When administering an MAOI in combination with pseudoephedrine, there is significant risk for hypertension.

Which conditions would alert a nurse to potentially unsafe treatment with pseudoephedrine? (Select all that apply.) a. Allergic rhinitis b. Glaucoma c. Hypertension d. Hyperthyroidism e. Osteoporosis

b, c, d Rationale: Narrow-angle glaucoma is a contraindication to treatment with pseudoephedrine because the condition may be worsened with treatment. This would alert a nurse to potentially unsafe treatment with the drug. Hypertension is a contraindication to treatment with pseudoephedrine because blood pressure may be significantly elevated with treatment, increasing the risk for stroke. This would alert a nurse to potentially unsafe treatment with the drug. Hyperthyroidism is a contraindication to treatment with pseudoephedrine because the condition may be worsened with treatment. This would alert a nurse to potentially unsafe treatment with the drug.

Which nursing considerations about acetylcysteine are accurate? (Select all that apply.) a. Acetylcysteine can be safely mixed with other drugs for administration. b. Patients with chronic obstructive pulmonary disease (COPD) should cautiously, if at all, use inhaled acetylcysteine. c. If the patient is also prescribed a bronchodilator, acetylcysteine should be given 10 to 15 minutes before the bronchodilator. d. Patients may develop runny nose, nausea, vomiting, drowsiness, headache, and dizziness while receiving acetylcysteine. e. For the common cold and other respiratory conditions, the most common route of administration for acetylcysteine is inhalation through a nebulizer.

b, d, e Rationale: This statement is true. Caution should be exercised in patients with respiratory illnesses like COPD. In some cases, the drug may not be advised for use. Runny nose, nausea, vomiting, drowsiness, headache, and dizziness are potential side effects a patient may experience when receiving acetylcysteine. Although acetylcysteine can be given orally or through inhalation via nebulizer, it is the inhaled route of administration that is generally used for respiratory conditions. The oral route is typically used for acetaminophen toxicity.

Which counseling point regarding the pharmacokinetics and pharmacodynamics of dextromethorphan would a nurse include in patient teaching? a. Dextromethorphan's effects last for about 12 hours. b. Because it is an opioid drug, it may cause analgesia and excessive drowsiness. c. The drug is an antitussive that works through suppressing the cough reflex within the cough center. d. The drug is well absorbed in the lungs when inhaled deeply through a nebulizer.

c Rationale: The drug is an antitussive that activates sigma opioid receptors in the cough center to suppress the cough reflex. It is a derivative of the opioid levorphanol but is not an opioid itself, which is why it activates opioid receptors.

By which mechanisms do expectorants loosen and thin respiratory secretions? (Select all that apply.) a. Direct activity with mucus to make it watery b. Activation of sigma opioid receptors within the cough center c. Direct stimulation of the secretory glands in the respiratory tract d. Reflex stimulation in response to irritation of the gastrointestinal tract e. Activation of alpha 1-adrenergic receptors to constrict the nasal blood vessels

c, d Rationale: Depending on the drug, an expectorant may loosen and thin respiratory secretions by direct stimulation of the secretory glands in the respiratory tract. Depending on the drug, an expectorant may loosen and thin respiratory secretions by reflex stimulation as a response to gastrointestinal irritation caused by the drug.

Which statements accurately describe the pharmacodynamics of dextromethorphan? (Select all that apply.) a. It can cause central nervous system (CNS) depression. b. It possesses analgesic properties. c. Its onset of action is 15 to 30 minutes. d. Both its time to peak concentration and duration of action are 2.5 hours. e. It suppresses the cough reflex by numbing the stretch receptor cells in the respiratory tract.

c, d Rationale: Patients can expect to initially experience results (i.e., onset of action) within 15 to 30 minutes of receiving dextromethorphan. Dextromethorphan reaches its peak concentration at 2.5 hours and it has a duration of action of 2.5 hours.

How long can a patient expect the effects of extended-release pseudoephedrine to last? a. 15 to 30 minutes b. 30 to 120 minutes c. 3 to 4 hours d. 8 to 12 hours

d Rationale: A patient can expect the effects of extended-release pseudoephedrine to last for 8 to 12 hours.

Case Study: Mr. Clark is a 63-year-old man who reports a worsening cough and nasal congestion. He went to an urgent care clinic 4 days prior and received a prescription for amoxicillin. The patient has a history of hypertension, erectile dysfunction, glaucoma, irritable bowel syndrome, and dyslipidemia. Vital signs are stable and similar to baseline with BP 137/92, HR 78, R 18, and pulse ox 94% on room air. Cardiac and respiratory assessment is unremarkable. The health care provider discontinues amoxicillin and prescribes an opioid antitussive with codeine to be used at bedtime for cough suppression and suggests that Mr. Clark buy dextromethorphan and pseudoephedrine to use during the day. Which explanation describes why the nurse would call the health care provider because of a safety concern for Mr. Clark? a. Dextromethorphan can significantly worsen his erectile dysfunction. b. Dextromethorphan and pseudoephedrine can potentially worsen Mr. Clark's glaucoma. c. Pseudoephedrine can worsen gastrointestinal symptoms such as diarrhea, thereby exacerbating his irritable bowel syndrome. d. The opioid antitussive represents a significant risk for abuse and addiction when given with pseudoephedrine and dextromethorphan, particularly in this patient.

d Rationale: Both dextromethorphan and pseudoephedrine can worsen glaucoma. They are sympathomimetic drugs that can stimulate alphal-adrenergic receptors and exacerbate the condition. He should avoid using these drugs.