What are the recommended medications and dosages for treating an acute cough?

Recommended Medications for Acute Cough

For acute cough management, dextromethorphan (30 mg every 6-8 hours, not exceeding 120 mg in 24 hours) is recommended for short-term symptomatic relief of dry, non-productive cough, while guaifenesin (10-20 mL every 4 hours for adults) is recommended for productive cough to increase mucus clearance. 1

Medication Selection Based on Cough Type

For Dry, Non-Productive Cough

1. Central Cough Suppressants

   • Dextromethorphan:

     • Adult dosage: 10 mL every 12 hours, not exceeding 20 mL in 24 hours 2
     • Alternative dosing: 30 mg every 6-8 hours, not exceeding 120 mg in 24 hours 1
     • Most appropriate for dry, irritating cough that prevents sleep
     • Lower abuse potential than codeine 1

   • Codeine (second-line option):

     • Recommended for short-term symptomatic relief in chronic bronchitis 3
     • Has greater side effect profile and higher abuse potential 1
     • Not recommended for cough due to upper respiratory infections 3

2. Peripheral Cough Suppressants

   • Levodropropizine and moguisteine:
     • Recommended for short-term symptomatic relief in chronic or acute bronchitis 3
     • Not recommended for cough due to upper respiratory infections 3

For Productive Cough

1. Expectorants

   • Guaifenesin:
     • Adult dosage: 10-20 mL (2-4 teaspoons) every 4 hours, not exceeding 6 doses in 24 hours 4
     • Helps thin mucus to facilitate clearance
     • Evidence for effectiveness is mixed 5, 6

2. Mucolytics

   • Hypertonic saline solution:
     • Recommended on a short-term basis to increase cough clearance in bronchitis 3
     • Can be administered via nebulizer

3. Anticholinergics

   • Ipratropium bromide (inhaled):
     • Recommended for cough suppression in upper respiratory infections and chronic bronchitis 3
     • Particularly useful for post-infectious cough 1

Treatment Algorithm

1. Assess cough characteristics:

   • Productive vs. non-productive
   • Duration (acute: <3 weeks; subacute: 3-8 weeks; chronic: >8 weeks)
   • Associated symptoms (fever, dyspnea, hemoptysis)

2. For dry, non-productive cough:

   • First-line: Dextromethorphan 30 mg every 6-8 hours
   • If sleep disruption is significant: Consider first-generation antihistamine at bedtime 1
   • If inadequate response: Consider codeine (with awareness of side effects and abuse potential)

3. For productive cough:

   • First-line: Guaifenesin 10-20 mL every 4 hours
   • Consider adding: Hypertonic saline nebulization
   • For bronchospasm component: Ipratropium bromide inhaler

4. Red flags requiring immediate medical attention:

   • Hemoptysis
   • Significant breathlessness
   • Prolonged fever
   • Worsening of pre-existing conditions 1

Important Considerations

• Avoid cough suppressants in productive cough as they may prevent necessary clearance of secretions 1
• Limited efficacy evidence: Many OTC cough medications show minimal benefit over placebo in clinical trials 5, 7, 6
• Combination products containing antihistamine-decongestants are not recommended until randomized controlled trials prove they are effective cough suppressants 3
• Albuterol is not recommended for acute or chronic cough not due to asthma 3
• Zinc preparations are not recommended for acute cough due to the common cold 3

Special Populations

• Children under 4 years: OTC cough medications not recommended due to limited benefit and potential risks 1
• Children over 1 year: Honey may be more effective than placebo or diphenhydramine 1
• Breastfeeding mothers: Use lowest effective dose for shortest duration; take medications immediately after breastfeeding 1
• Elderly patients: Seek medical evaluation if cough persists beyond 1-2 weeks or is accompanied by concerning symptoms 1

Monitoring and Follow-up

• If cough persists beyond 1-2 weeks, medical evaluation should be sought to rule out underlying conditions 1
• Consider referral to specialist if cough persists despite appropriate treatment trials or if diagnostic uncertainty remains 1