This chapter is designed to aid in the preparation for the Pharmacy Examining Board of Canada (PEBC) exams and can be used for both the Evaluating Exam (EE) and the Qualifying Exam (MCQ). It provides a comprehensive, yet concise, overview of acute bronchitis, including its etiology, clinical features, investigations, management options, and pharmacologic treatments. A complete drug list and information on natural health products are also included, making it a valuable resource for exam preparation.
Acute Bronchitis Overview
Acute bronchitis is characterized by the acute onset of cough, with or without sputum production, lasting less than 3 weeks. It is a transient inflammation of the trachea and bronchi, predominantly caused by viral infections (>90% of cases). Differentiation from other respiratory conditions like viral rhinitis, asthma, and community-acquired pneumonia is essential. Symptoms typically resolve within 18 days but may last up to 8 weeks.
Etiology
Viral (>90%):
Infants (<1 year): RSV, parainfluenza.
Children (1-10 years): Parainfluenza, enterovirus, RSV.
Adults (>10 years): Influenza, parainfluenza, rhinovirus, adenovirus.
Bacterial (5-10%):
Chlamydophila pneumoniae, Mycoplasma pneumoniae, Bordetella pertussis, B. parapertussis.
Note: Streptococcus pneumoniae and Haemophilus influenzae do not commonly cause acute bronchitis in adults without underlying lung disease.
Noninfectious:
Chemical or fume inhalation, tobacco smoke, and other pulmonary irritants.
Clinical Features and Diagnosis
Primary Symptom: Cough, potentially lasting up to 8 weeks.
Other Symptoms: Nasal congestion, wheezing, mild respiratory distress, low-grade fever.
Physical Exam: Normal heart and respiratory rates, absence of chest abnormalities, and fever below 38°C suggest acute bronchitis. A chest X-ray is generally unnecessary unless pneumonia is suspected (e.g., fever >38°C, abnormal breath sounds).
Differential Diagnosis: Consider viral rhinitis, asthma, COPD exacerbation, pneumonia, foreign body aspiration.
Investigations
Routine chest X-rays, viral cultures, sputum tests, and pulmonary function tests are not recommended unless other conditions are suspected.
Procalcitonin: May help differentiate bacterial infections, though routine use is limited.
Testing for influenza or COVID-19 should follow local guidelines when suspected.
Management
Nonpharmacologic Interventions
Patient Education: Explain the viral nature of bronchitis and expected symptom duration (2-3 weeks).
Avoid Irritants: Tobacco smoke and other pulmonary irritants should be avoided.
Supportive Care:
Rest, hydration, and humidification of air.
Hand hygiene and cough etiquette to limit transmission.
Pharmacologic Management
Antipyretics and Analgesics: Acetaminophen or ibuprofen for fever and discomfort.
Antitussives: Codeine and dextromethorphan may provide symptom relief but are not recommended for children under 18 years of age.
Bronchodilators: Short-acting beta2-agonists (salbutamol) are recommended only in cases with wheezing or bronchial hyper-responsiveness and not for routine use.
Corticosteroids: No evidence supports the use of inhaled or oral corticosteroids in acute bronchitis.
Antibiotics
Not recommended for uncomplicated cases of acute bronchitis, as most are viral. Antibiotics have a minimal impact (e.g., reducing cough duration by half a day) but may increase the risk of antibiotic resistance.
Patient Communication: It is important to explain that antibiotics do not work for viral infections and outline the risks, such as side effects and antibiotic resistance.
Natural Health Products
Honey: A recent meta-analysis found honey to be superior to usual care (e.g., diphenhydramine, dextromethorphan, nonpharmacologic treatments) in improving cough frequency and severity in adults and children over 1 year old. Note: Honey should not be given to children under 1 year due to the risk of botulism.
Pelargonium sidoides: An herbal remedy (also known as South African geranium), which may provide relief for symptoms of acute bronchitis. Some randomized controlled trials (RCTs) suggest effectiveness, but overall evidence is insufficient to recommend routine use. Adverse Effects: Possible allergic reactions, GI upset, and liver toxicity.
North American Ginseng: Prophylactic use of North American ginseng extract has been found to reduce the duration of the common cold. However, its effect on acute bronchitis has not been specifically studied.
Chinese Herbal Medicine: There is insufficient evidence to recommend Chinese herbal medicines for treating acute bronchitis.
Pregnancy and Breastfeeding
Acetaminophen: Considered safe for fever and discomfort.
NSAIDs: Should be avoided in late pregnancy due to the risk of fetal complications.
Dextromethorphan: Safe for cough relief, but caution is advised when using opioids near term or during breastfeeding.
Prevention
Vaccination: Annual influenza vaccination is recommended for individuals over 6 months of age, particularly those in high-risk groups.
Hand Hygiene: Encourage frequent handwashing and proper cough etiquette to limit spread.
Prognosis
Acute bronchitis is generally self-limiting, resolving within 2–3 weeks. If symptoms persist beyond 3 weeks, further investigation for asthma, COPD, or other conditions may be necessary.
Drug List for Symptomatic Management of Acute Bronchitis
Drug Class | Drug Name | Dosage | Adverse Effects |
Analgesics Antipyretics | Acetaminophen | Adults: 325–650 mg Q4–6H PO; max 4g/day. Children: 10–15 mg/kg Q4–6H PO | GI upset, potential for hepatic damage with overdose. |
Ibuprofen | Adults: 200–400 mg TID-QID PO; max 2.4g/day. Children: 5–10 mg/kg Q6–8H PO | GI upset, increased risk of GI bleeding, contraindicated in peptic ulcer. | |
Antitussives | Codeine | Adults: 10–20 mg Q4–6H PO; max 120 mg/day | Sedation, nausea, constipation, caution in elderly and breastfeeding. |
Dextromethorphan | Adults: 30 mg Q6–8H PO; max 120 mg/day. Children: 15 mg Q6–8H PO | Nausea, drowsiness, caution with CNS depressants and SSRIs. | |
Bronchodilators | Salbutamol | Adults/Children ≥4 y: 1–2 puffs QID PRN. Max: 800 mcg/day | Tremor, dizziness, tachycardia, contraindicated in arrhythmias. |
Terbutaline | Adults/Children ≥6 y: 1 inhalation QID PRN. Max 6/day | Tremor, nausea, contraindicated arrhythmias and cardiac conditions. |
Notes:
In the vast majority of cases, supportive care is sufficient, and antibiotics are not necessary.
Patient satisfaction is often linked to clear communication, not the prescription of antibiotics.
Educating patients about the viral nature of bronchitis reduces unnecessary antibiotic use.
Set patient expectations that the cough may persist for 2–3 weeks to improve understanding.
Acute Bronchitis – Pharmapass.ca | ||
Step | Criteria | Action/Next Step |
1. Initial Symptoms | Acute onset cough (<3 weeks) ± sputum | Proceed to Step 2. |
2. Rule Out Other Causes | GERD, COVID-19, Heart failure, PE, ACE inhibitor ADR | If any cause is identified, treat accordingly. If not, proceed to Step 3. |
3. Check for Additional Symptoms | Fever, Increased respiratory rate, Tachycardia, Consolidation, Airway obstruction | Yes: Consider pneumonia, asthma, or other pulmonary disease. No: Proceed to Step 4. |
4. Outbreak Considerations | During documented outbreaks (e.g., Influenza, Pertussis) | Yes: Treat as appropriate. No: Proceed to Step 5. |
5. Acute Bronchitis Diagnosis | Diagnosis of acute bronchitis confirmed | Follow these actions: 1. Cough may last up to 21 days (50% may last up to 8 weeks). 2. Educate on viral cause and lack of antibiotic need. 3. Encourage fluid intake and humidity. 4. No routine treatment; check symptom management options. 5. Educate when to reassess: worsening symptoms, fever, etc. |