What Pharmacists Should Know About Postnasal Drip

Nearly 40% of the total population will complain of chronic cough over the course of their lifetime.

Chronic cough, which is defined as a cough lasting longer than 8 weeks, is both annoying to patients and disruptive to those around them.

Isolated idiopathic chronic cough falls into 3 categories:

1. Cough variant asthma

2. Gastroesophageal reflux disease (GERD)

3. Postnasal drip/upper airway cough syndrome

Ninety percent of chronic cough symptoms are linked to this triad, with the exclusion of smoking status and angiotensin-converting enzyme (ACE) inhibitor use.

A team of researchers from Philadelphia sought to describe the origin of postnasal drip and its management with and without cough.

Postnasal drip was first defined by British otolaryngologist H. Dobell as a tickling cough that is most aggravated in the morning and at night. In 2006, the American College of Chest Physicians renamed it “upper airway cough syndrome” because new evidence suggested that the condition was more related to a baseline cough hypersensitivity than chronic laryngeal and pharyngeal irritation from nasal secretions.

Although objective diagnostic tools for upper airway cough syndrome would be helpful, none exist. Still, evaluation of a patient with chronic cough should include an assessment of smoking status, ACE inhibitor use, GERD, and cough variant asthma as the cause of cough. Chest radiographs can also be used to determine whether there is a pulmonary cause.

If the problem is not related to a pulmonary cause, health care providers should find out if the condition is upper airway cough syndrome.

“Upper airway cough syndrome is often thought to be sinonasal in origin, and identification of sinusitis or rhinitis is paramount in management,” the researchers noted.

Upper airway cough syndrome caused by allergic rhinitis should be managed with nasal/oral antihistamine, nasal steroid, cromolyn, or a leukotriene inhibitor. Affected individuals need to avoid allergens in addition to adhering to therapy.

Health care providers should manage upper airway cough syndrome caused by nonallergic rhinitis with first-generation antihistamines or decongestants. Intranasal ipratropium may provide symptomatic relief, as well.

When upper airway cough syndrome is associated with acute or chronic sinusitis, clinicians should prescribe antibiotics, intranasal steroids, and/or decongestants. First-generation antihistamines are first-line treatment for upper airway cough syndrome prior to further symptomatic evaluation and work up.

These findings were published in the February 2016 issue of Current Opinion.