Dextromethorphan is an example of an antitussive (see Figure 5.10[1]).

 

Photo showing various packages of Robitussin medications
Figure 5.10 Robitussin DM, an OTC Medication Containing Dextromethorphan and Guaifenesin

Mechanism of Action: Dextromethorphan suppresses a cough by depressing the cough center in the medulla oblongata or the cough receptors in the throat, trachea, or lungs, effectively elevating the threshold for coughing.

Indications: Antitussives are used for a dry, hacking, nonproductive cough that interferes with rest and sleep.

Nursing Considerations: This medication is not safe for children under the age of 4 years.

Side Effects/Adverse Effects: The most common side effects include nausea and drowsiness. Some patients may experience a rash or difficulty breathing. High doses may cause hallucinations and disassociation, and the drug has been reported to be used as a recreational drug.[2]

Patient Teaching & Education: Patients should take care to avoid irritants that stimulate their cough. Additionally, antitussive medications can cause drowsiness, and patients should avoid taking them with other CNS depressants or alcohol.[3]

Now let’s take a closer look at the medication grid on dextromethorphan & benzonatate in Table 5.8a.[4],[5],[6]

Table 5.8a Dextromethorphan & Benzonatate Medication Grid

Class/Subclass
Prototype/Generic
Administration Considerations
Therapeutic Effects
Adverse/Side Effects
Non-opioid antitussive dextromethorphan

 

 

Take as directed

Administer undiluted

No alcohol use due to CNS depression

Use with caution in patients with respiratory disease and with those taking monoamine oxidase inhibitors  (MAOIs)

Temporarily relieves coughing due to minor throat and bronchial irritation as may occur with the common cold CNS: Sedation and dizziness

Mild gastrointestinal effects

Non-opioid antitussive benzonatate Benzonatate should be taken with food to minimize the risk of gastrointestinal upset. It should be swallowed whole and not crushed, chewed, or dissolved in the mouth)

No alcohol use due to CNS depression

Benzonatate can cause respiratory depression in high doses, especially in patients with preexisting respiratory conditions

Benzonatate may interact with other medications, including opioids, benzodiazepines, and alcohol

Utilized to treat of cough associated with respiratory infections and conditions such as bronchitis and pneumonia CNS: Sedation, dizziness

GI: Constipation, nausea

Headache

Dry mouth

Nasal congestion

Itching or skin rash

Codeine/guaifenesin is another example of an antitussive medication. It is combination medication that contains the opioid pain medication codeine and the expectorant guaifenesin.

Mechanism of Action: Codeine works by binding to mu opioid receptors in the brain and spinal cord. This binding reduces the transmission of pain signals and suppresses the cough reflex in the brainstem Guaifenesin is an expectorant that works by thinning and loosening mucus in the airways.

Indications: Codeine is a centrally-acting cough suppressant that works by reducing the cough reflex in the brainstem. It is effective at reducing both dry and productive coughs. Guaifenesin is an expectorant that works by thinning and loosening mucus in the airway.

Nursing Considerations: With the risk of respiratory depressions associated with this medication, baseline respiratory effort must be assessed. Nurses should monitor for signs of dependence as codeine has the potential for abuse and dependence.

Side Effects/Adverse Effects: Side effects include sedation and drowsiness. It is important to also monitor for respiratory depression, blurred vision, dry mouth, urinary retention, nausea, vomiting, and constipation.

Patient Teaching & Education: Patients should take care to avoid irritants that stimulate their cough. Additionally, antitussive medications can cause drowsiness, and patients should avoid taking them with other CNS depressants or alcohol.  Patients should not drive or operate heavy machinery while taking the medication due to the potential for sedation.[7]

Now let’s take a closer look at the medication grid on codeine-guaifenesin in Table 5.8b.[8]

Table 5.8b Codeine-guaifenesin Medication Grid

Class/Subclass
Prototype/Generic
Administration Considerations
Therapeutic Effects
Adverse/Side Effects
Opioid antitussive codeine-guaifenesin Take as directed. Monitor for signs of abuse/dependence

Administer in the lowest effective dose for the shortest duration possible to minimize the risk of adverse effects

No alcohol use due to CNS depression

Use with caution in patients with respiratory disease and with those taking benzodiazepines, antidepressants, and other opioids

Alleviates coughing and loosens mucus in the airways CNS: Sedation and dizziness

Respiratory despression

Blurred vision, dry mouth, and urinary retention

GI: Constipation, nausea, vomiting

 

 


  1. Robitussin Cough Cold Flu Congestion decongestant Relief Medicine” by Mike Mozart is licensed under CC BY 2.0
  2. Frandsen, G., & Pennington, S. (2018). Abrams’ clinical drug: Rationales for nursing practice (11th ed.). Wolters Kluwer.
  3. uCentral from Unbound Medicine. https://www.unboundmedicine.com/ucentral
  4. This work is a derivative of Pharmacology Notes: Nursing Implications for Clinical Practice by Gloria Velarde licensed under CC BY-NC-SA 4.0
  5. Frandsen, G., & Pennington, S. (2018). Abrams’ clinical drug: Rationales for nursing practice (11th ed.). Wolters Kluwer.
  6. This work is a derivative of DailyMed by U.S. National Library of Medicine in the Public Domain.
  7. uCentral from Unbound Medicine. https://www.unboundmedicine.com/ucentral
  8. This work is a derivative of DailyMed by U.S. National Library of Medicine in the Public Domain.

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