Respiratory System Disorders

Introduction

Respiratory system diseases are divided into upper and lower respiratory system disorders. Upper respiratory system disorders are diseases specific to the upper part of the respiratory system, such as the nose and throat. The most common upper respiratory diseases are cold and flu.

Lower respiratory system disorders are more severe than upper respiratory system diseases. They often require hospitalization, chronic use of medications, and lifestyle improvements. The most common lower respiratory system disorders are asthma, COPD, bronchitis, and pneumonia.

 

Common Cold

The chances are good that you've had a cold. The common cold is an extremely common viral disease. 

The common cold is more common and lasts longer in children. It's also highly contagious. The best way to prevent the common cold is thorough handwashing and avoiding contact with sick people.

The common cold usually starts with a scratchy throat, followed by a runny nose. On days 3 and 4, chest congestion starts due to the buildup of mucus in the upper respiratory tract, leading to a cough. On days 6 and 7, patients generally start feeling better.

The common cold doesn't require antibiotics because it isn't a bacterial infection. Patients are treated with medications for symptom management.

 

The symptoms of the common cold include

• Scratchy or sore throat
• Nasal congestion, sneezing, sniffing, or runny nose
• Chest congestion
• Cough (productive or nonproductive)
• Body aches
• Tiredness
• Fever (most common in children)

 

Decongestants

Decongestants are used to dry excessive mucus and open up the nasal passageway.

Most decongestant medications are available OTC without prescription. Side effects of these medications include dryness of mouth and wakefulness, so it's recommended to drink plenty of water and avoid taking these medications in the evening or at bedtime.

Some commonly used decongestant medications are

• Pseudoephedrine (Sudafed)
• Phenylephrine (Sudafed PE)
• Oxymetazoline (Afrin)—nasal drops

First-Generation Antihistamines 

Antihistamines are commonly used to treat symptoms such as runny nose, sneezing, and sore throat. Antihistamines are classified as first generation and second generation. 

First-generation antihistamines target more general receptors in the central nervous system and have more side effects than second-generation antihistamines. 

Some examples of first-generation antihistamines are 

• Diphenhydramine (Benadryl)
• Hydroxyzine (Atarax, Vistaril)
• Brompheniramine (Bromax)
• Chlorpheniramine (Chlortrimeton) 
• Azelastine (Astelin)—nasal spray 

Second-Generation Antihistamines

Antihistamines are commonly used to treat symptoms such as runny nose, sneezing, and sore threat. Antihistamines are classified as first-generation and second generation. 

Second-generation antihistamines are known to cause fewer side effects of dizziness, drowsiness, and dry mouth. Also, these medications are taken only once or twice daily, compared to taking multiple doses of first-generation antihistamines.

Some examples of second-generation antihistamines are 

• Fexofenadine (Allegra)
• Loratadine (Claritin)
• Desloratadine (Clarinex)—disintegrating tablet
• Cetirizine (Zyrtec) 

Cough Medications

One symptom of the common cold is a cough, which usually starts on day 3 or 4. Coughing is the body's way of trying to eliminate mucus that's been building up in the upper respiratory tract. Cough suppressant medications act on the central nervous system to suppress the urge to cough, and expectorants help bring out the mucus. 

Some examples of commonly used cough medications are

Dextromethorphan (Delsym)—cough suppressant

• Guaifenesin (Robitussin)—expectorant
• Benzonatate (Tessalon)
• Hydrocodone-homatropine (Hycodan)
• Promethazine/dextromethorphan (Phenergan) 

Pain and Fever Medications

Pain and fever medications are used to treat symptoms of body pain, lethargy, and fever.

Some examples of commonly used medications for pain and fever are

• Acetaminophen (Tylenol)
• Ibuprofen (Motrin)
• Naproxen (Aleve)

Aspirin is also a pain and fever reducer but not commonly recommended due to the risk of bleeding and developing gastric ulcers. Aspirin isn't recommended for children due to the risk of a rare but dangerous disease called Reye's syndrome.

Other Treatments

Other treatments for cold symptoms are

• Plenty of fluids to help treat the side effects of cold medications and loosen mucus
• Rest until symptoms resolve and the cold virus runs its course (five to seven days)
• Vitamin C and zinc to boost the immune system and help prevent frequent cold infections
• Eucalyptus and other herbal medications to help relieve cold symptoms

 

Influenza

Influenza, commonly known as the flu, is also a viral infection that's caused by the influenza virus. As with the common cold, antibiotics are ineffective in treating flu. The best option is to prevent the flu by thorough handwashing and immunization.

The flu is very common and is sometimes considered a mild disease. However, the flu shouldn't be ignored. It can cause life-threatening complications if not treated. The flu is treated in the same way as the common cold. The difference between a cold and the flu is that the flu is usually a more severe form of a cold. The flu generally has more severe symptoms, such as fever and dehydration. If untreated, the flu can possibly lead to pneumonia and hospitalization. 

 

Seasonal flu vaccines are extremely important for high-risk people. High-risk people include

• The elderly
• Children
• Pregnant women
• People with chronic diseases
• People with compromised immune systems
• Healthy adults living with high-risk people
• Healthy adults caring for high-risk people

 

Treatment for symptoms of the flu is the same as the treatment of cold symptoms. Decongestants, antihistamines, cough, and pain and fever medications (previously described with cold treatments) are all used to provide symptomatic relief for the flu. However, the flu must run its course.

Some antivirals are available to treat the flu. While antibiotics can cure bacterial infections, there's no cure for viruses. Antibiotics are more effective than antivirals, but not against viral infections. Antivirals can only shorten the length of an illness or reduce the severity of symptoms. To be effective, antivirals must be taken within 36 to 48 hours of the start of symptoms. Patients don't usually seek treatment until they've had symptoms for 48 hours. 

Two examples of commonly used antiviral medications to treat the flu are

• Oseltamivir (Tamiflu)
• Zanamivir (Relenza) inhaler

 

Asthma and COPD

There are beta-2 receptors in the lungs similar to beta receptors in the heart.  You've already learned that beta blocker medications work on beta receptors in the heart to treat hypertension and other cardiovascular disorders. Beta-2 receptor agonists (meaning these medications enhance the effect of beta-2 receptors) act similarly in the lungs to cause smooth muscle relaxation. There are two kinds of beta-agonist inhalers—short acting and long acting. 

Short-acting

Short-acting beta-agonist inhalers are used to provide quick relief. 

Some examples of short-acting inhalers are

• Albuterol HFA
• Levalbuterol (Xopenex)
• Pirbuterol (Maxair)

While not an inhalant, epinephrine (adrenaline) functions very similarly to a short-acting inhaler. Epinephrine is used as an anti-anaphylactic to treat airway obstruction brought on by severe allergic reaction. People who are allergic to such things as nuts, bee stings, or latex will often carry an epinephrine auto-injector for emergency situations. 

Long-acting

Long-acting beta-agonist inhalers have a slower onset of action but provide relief for a longer period and are used as maintenance therapy in combination with steroid inhalers. Steroid medications simply produce an anti-inflammatory effect in the lungs. 

Some examples of long-acting inhalers are

• Salmeterol/fluticasone (Advair)
• Formoterol/budesonide (Symbicart)
• Vilanterol/fluticasone (Breo Ellipta) 

The first drug listed in the combination of inhalers is the long-acting beta-agonist, and the second drug is the steroid. These medications are usually given on a scheduled basis (that is, every 12 hours). 

 

Other medications for asthma and COPD include

Anticholinergic Medications

Anticholinergic medications are also used to prevent constriction of the smooth muscle surrounding airways. These medications are mainly used as a long-term therapy of COPD, but ipratropium may also be used for immediate relief of asthma symptoms. These medications are also available as inhalers.

Examples of anticholinergic medications are

• Ipratropium bromide (Atrovent)
• Tiotropium (Spiriva)

Side effects of these medications are dry mouth, nausea, and a metallic taste in the mouth.

Inhaled Corticosteroids

Corticosteroid medications make up another class of medications that are commonly used as maintenance therapy to help reduce airway obstruction by decreasing inflammation. It takes two to three weeks for these medications to exert some effect, and it may take from six to eight weeks for maximum symptom relief. 

Some examples of steroid inhalers are 

• Budesonide (Pulmicort)
• Fluticasone (Flovent)
• Mometasone (Asmanex)

Side effects of the steroid inhalers include a sore throat, a bad taste in the mouth, and thrush (a fungal infection). Patients are instructed to rinse their mouths after each dose of the steroid inhaler.

Oral/Injectable Corticosteroids 

Some examples of oral/injectable corticosteroids are

• Prednisone (Deltasone)
• Prednisolone (Omnipred)
• Dexamethasone (Maxidex)
• Methylprednisolone (Medrol)

Leukotriene Modifiers

Leukotriene modifiers work by producing bronchodilation to improve allergy or asthma symptoms.

Examples of leukotriene modifiers are

• Montelukast (Singulair)
• Zafirlukast (Accolate)

Both of these medications are available as oral agents and aren't as effective as other treatment options for controlling asthma and allergy symptoms.

 

Bronchitis

Bronchitis is the acute or chronic inflammation and/or infection of the mucous membranes of the bronchial passages of the respiratory tract. The main symptom of acute bronchitis is a cough lasting for more than five to seven days.

Acute bronchitis is generally self-limiting, and treatment is targeted for symptom relief. On the other hand, chronic bronchitis patients with a productive cough that persists for several months may need further evaluation to possibly diagnose asthma or COPD.

Bronchitis is primarily caused by a viral infection and rarely needs antibiotic therapy. Due to increasing trends of antibiotic resistance, many healthcare organizations are taking steps to ensure antibiotics aren't prescribed regularly for acute bronchitis.

Patients commonly use acetaminophen, ibuprofen, and naproxen to treat pain and reduce inflammation. Patients can use guaifenesin and dextromethorphan to relieve coughing.

 

Pneumonia

Pneumonia is usually a bacterial infection but can sometimes be viral. Pneumonia symptoms are differentiated from acute bronchitis by the presence of a fever and a sever productive cough. Pneumonia is further classified as community-acquired pneumonia (CAP) or healthcare-associated pneumonia (HCAP). It's important to identify which type of microorganism is likely to be responsible for the infection. Certain microorganisms that exist in healthcare settings can cause a more severe form of disease and are likely to resist first-line antibiotics.

 

Treatment of pneumonia often requires antibiotics. The type of antibiotic depends on various factors, including the type of organism causing the infection, age, severity, diagnosis of CAP or HCAP, resistant patterns, and comorbidities. 

Some commonly used antibiotics for pneumonia are

• Cephalexin (Keflex)
• Cefdinir (Omnicef)
• Amoxicillin/clavulanate (Augmentin)
• Azithromycin (Zithromax)
• Moxifloxacin (Avelox)
• Ciprofloxacin (Cipro)
• Minocycline (Minocin)
• Piperacillin/tazobactam (Zosyn)
• Ampicillin/sulbactam (Unasyn)
• Vancomycin (Vancocin)
• Linezolid (Zyvox)

 

Key Points

• Inhalers are commonly used medications to treat asthma and COPD.
• Influenza or flu is a viral infection that can be prevented with good hand hygiene and vaccination.
• The common cold is also a viral infection that doesn't require antibiotic treatment.
• Second-generation antihistamines provide the benefit of fewer side effects of dizziness, drowsiness, and dry mouth compared to first-generation antihistamines.
• Cough medications are cough suppressants such as dextromethorphan or expectorants such as guaifenesin. 
• Most cold and cough medications are available as combination products over the counter.