Respiratory: Expectorants Flashcards
Types of Respiratory Drugs:
Bronchodilators: Beta2-Receptor Agonists:
Basic Understanding:
Guaifenesin is the only expectorant ingredient listed by the
FDA panel as having scientific evidence of safety and efficacy.
Guaifenesin is indicated as an expectorant in the symptomatic treatment of cough due to the common cold and mild
upper respiratory infections.
Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Examples:
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Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Pharmacodynamics:
Guaifenesin’s main mechanism of action is to increase the
output of the respiratory tract by decreasing adhesiveness and
surface tension. The increased flow of the thinned secretions
promotes ciliary action and facilitates the removal of respiratory mucus. This changes a dry, nonproductive cough into
a more productive cough.
Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Pharmacokinetics: Absorption and Distribution:
Guaifenesin is rapidly absorbed from the GI tract after oral
administration. Distribution is unknown. It is not known
whether guaifenesin crosses the placenta or is distributed in
breast milk.
Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Pharmacokinetics: Metabolism and Excretion:
The exact mechanism of metabolism of guaifenesin is unknown. Its major metabolite, beta (2-methoxyphenoxy) lactic
acid, is excreted in the urine.
Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Pharmacotherapeutics: Precautions and Contraindications:
Guaifenesin is not to be used for persistent cough, such as
that found with smoking, asthma, or emphysema. Cough
related to heart failure or angiotensin-converting enzyme
(ACE) inhibitor therapy should not be treated with guaifenesin. A cough accompanied by high fever or lasting longer
than 7 days should be evaluated by a health-care provider.
Guaifenesin is Pregnancy Category C. There have been
no problems documented in breastfeeding women taking
this medication. Use in children as young as age 2 years is
considered safe.
Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Pharmacotherapeutics: Adverse Drug Reactions:
GI upset, nausea, and vomiting are the most commonly reported adverse effects of guaifenesin. Drowsiness, diarrhea,
dizziness, rash, and headache have also been reported.
Guaifenesin is contraindicated only if the patient is hypersensitive to guaifenesin
Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Pharmacotherapeutics: Drug Interactions:
There are no drug interactions of significance with guaifenesin; however, guaifenesin may cause false readings in certain
laboratory determinations of 5-hydroxyindoleacetic acid
(5-HIAA) and vanillylmandelic acid (VMA).
Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Pharmacotherapeutics: Rational Drug Selection:
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Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Pharmacotherapeutics: Monitoring
There is no specific laboratory monitoring required with the
use of guaifenesin.
Types of Respiratory Drugs:
Bronchodilators: B2RAs:
Pharmacotherapeutics:
Patient Education:
Administration
The patient should be aware of the proper dose of guaifenesin. The patient should be using a calibrated medication
spoon and taking the appropriate dose per age.
Guaifenesin is an OTC product, and patients may selfmedicate, often without proper understanding of the medication. The provider may assist the patient in making the proper
choice of cough medication by explaining the difference between the OTC products guaifenesin and dextromethorphan.
An explanation of the many combination products that are
available and some guidance about appropriate use will assist
the patient in making an informed choice.
Adverse Reactions
Although the adverse drug reactions of guaifenesin are mild,
patients should be instructed regarding the mild gastrointestinal upset that may occur.
Lifestyle Management
Patients should be instructed to remain well hydrated
while taking guaifenesin, and they should refrain from
smoking
