A cough is a spontaneous reflex. When an irritant disturbs the airways or the throat, the body automatically responds by coughing. Coughs help clear dust, germs, and mucus and are a normal response to protect the body.

Although an occasional cough is normal, a persistent cough is not and may require a trip to a physician.1

TYPES OF COUGH
A cough presents in many medical conditions and can indicate anything from a simple clearing of the throat to a serious medical condition. The type of cough can help clinicians differentiate possible causes.

The duration of a cough is an important factor in determining cause. An acute cough has a rapid onset and lasts up to 3 weeks. A subacute cough lasts between 3 and 8 weeks, and a chronic cough lasts for more than 8 weeks.2 Coughs are further classified as a dry cough (does not bring up phlegm), hemoptysis (brings up blood), a nocturnal cough (happens only at night), and a productive cough (brings up phlegm).2

COMMON COMORBID SYMPTOMS
A cough can occur alone or with other symptoms. A cough that occurs with other symptoms is typically a sign of certain diseases of the heart, lungs, nervous system, and stomach.2 These symptoms can include chills, decreased exercise tolerance, difficulty swallowing, fever, heartburn, night sweats, runny nose, shortness of breath, sore throat, weight loss, and wheezing.

CAUSES
Acute cough has many causes, the most common being upper respiratory tract infections such as the common cold, the flu, and viral laryngitis. Other causes include gastroesophageal reflux disease (GERD), hay fever, inhalation of irritants, lower respiratory tract infections, pulmonary embolism, pneumothorax (collapsed lung), postnasal drip, and pulmonary edema (heart failure).2

Causes of a chronic cough include asthma, chronic lung infections, chronic obstructive pulmonary disease, lung cancer, and pulmonary disease. Some medications, such as angiotensin-converting enzyme inhibitors, can also cause a chronic cough.2

MANAGING A COUGH
Patients can manage their coughs nonmedically and with OTC medications.

Nonmedical therapies include plenty of fluids to keep phlegm pliable and thin and soothe a dry throat. Use of a humidifier, as well as breathing in and drinking warm fluids such as soup and tea, also helps. Patients should avoid alcohol, as it impairs the body’s immune system, and dairy products, as they tend to thicken mucus.3

Natural remedies can be quite effective in relieving a cough. Bromelain is an enzyme found in pineapple and has both antiinflammatory and mucolytic properties. Ginger has anti-inflammatory properties and is also good for an asthmatic or dry cough. Honey can coat the throat and relieve a dry cough. Marshmallow root and slippery elm bark produce a thick substance that coats the throat. Marshmallow root is available online and in health stores as an ingredient in herbal cough syrup and as a dry herb or bagged tea. A saltwater gargle can reduce mucus and phlegm, thereby reducing the need to cough.4 Slippery elm bark is found in health stores and online in capsule and powder forms.4

Dietary changes may be necessary to help ease a cough caused by GERD. Patients should avoid the beverages and foods that typically trigger GERD, including alcohol, caffeine, chocolate, citrus foods, fatty and fried foods, garlic and onions, mint, spices and spicy foods, and tomatoes and tomato-based products.4

OTC medications can help relieve a cough. For a dry, nonproductive cough, the cough suppressant dextromethorphan works well. For a productive cough, an expectorant, such as guaifenesin, loosens mucus in the airways to keep it thin and better able to be expelled.3 A nasal lavage or a saline nasal spray can help prevent a cough caused by dry throat or postnasal drip by keeping the back of the throat clear.3

Parents should not use OTC cold and cough products, aside from saline nasal spray, in children age 2 years. Additionally, some cold and cough products carry the potential to be abused. Some states allow only individuals 18 years and older to purchase them.

SEEKING MEDICAL HELP
Pharmacists should advise individuals to seek medical attention if they experience a cough that worsens; ear pain; a flare-up of any chronic lung problems, such as asthma and chronic obstructive pulmonary disease; a high-grade fever; severe or unusual cold symptoms; or a sinus headache.3

Individuals should seek immediate medical attention if they have a cough for more than 8 weeks, experience an improvement in a cough and a worsening or unexplained weight loss with a cough, have chest pain or trouble breathing with a cough, spit up blood with a cough, or vomit with a cough.

DEBUNKING MYTHS
Patients are taking much more interest in their own health care now more than ever before. This is good. Unfortunately, the array of false information out there often confuses and misinforms patients.

Below are some of the most common myths associated with a cough5:
  • All coughs are contagious. A cough from airway irritation, allergies, or asthma is not contagious. Coughs caused by a bacterial or viral infection, on the other hand, are most likely contagious. A cough can propel air and particles from the lungs and the throat at speeds nearing 50 mph.1 Therefore, practitioners should remind patients to reduce the spread of infection by following proper protocol for coughing, hand washing, sneezing, tissue use, and wearing a mask.6
  • Antibiotics cure a cough. A cough is most commonly caused by viral infections. Because antibiotics kill only bacteria, they seldom have an effect on cough. Bronchitis and pneumonia are 2 diseases caused by bacteria that do have a cough as a symptom. Therefore, antibiotics may be effective.
  • Hot soup can cure a cough. Although hot soup can decrease irritation and soothe the throat, thereby easing the cough, it does nothing to cure the respiratory condition causing the cough.
  • Infections cause all coughs. An occasional cough does not indicate a health condition or problem. However, frequent coughing may be a sign of something more serious irritating the throat. This may or may not be due to an infection.
  • Vaccinations will prevent a cough. Vaccinations have no effect on noninfectious causes of cough. The pertussis vaccine is effective, especially within the first year after vaccination. After 2 years, the effect decreases over time. The annual flu vaccine will help protect against the flu and its associated cough. However, patients may not be fully protected.

CONCLUSIONS
Pharmacists are often the first line of contact with patients, as they are trusted professionals and often more accessible than other health care providers. They have the opportunity to help patients with a cough by knowing when to recommend natural or OTC remedies, which can also reduce health care costs. More important, pharmacists know when to recommend that a patient seek medical attention or immediate medical attention. Pharmacists are among the few who can look at a patients’ medication histories to see whether they are taking any medications that cause cough, which ultimately can be benign or very serious. 
 
Kathleen Kenny, PharmD, RPh, has more than 25 years of experience as a community pharmacist and is a freelance clinical medical writer based in Colorado Springs, Colorado.


REFERENCES
  1. Learn about cough. American Lung Association website. lung.org/lung-healthand-diseases/lung-disease-lookup/cough/learn-about-cough.html. Updated March 13, 2018. Accessed February 2, 2020.
  2. Cough symptoms, causes and risk factors. American Lung Association website. lung.org/lung-health-and-diseases/lung-disease-lookup/cough/cough-symptomscauses- risks.html. Updated July 11, 2019. Accessed February 2, 2020.
  3. Patient education: cough or cold, what to take. University of Florida website. shcc.ufl.edu/services/primary-care/self-help-resources/health-care-info-online/patienteducation- cough-or-cold-what-to-take/. Accessed February 11, 2020.
  4. Leonard J. What can I do to make my cough go away? Medical News Today website. medicalnewstoday.com/articles/322394.php#tips-to-help-prevent-a-cold. Published January 1, 2020. Accessed February 11, 2020.
  5. 7 myths about cough. Health 24 website. health24.com/Medical/Cough/News/ 7-myths-about-cough-20170508. Updated October 23, 2017. Accessed February 2, 2020.
  6. Cough. American Thoracic Society website. thoracic.org/patients/patientresources/ resources/cough.pdf. Accessed February 2, 2020.