What is the recommended dosage and treatment approach for Getitussin (dextromethorphan) for cough suppression?

Getitussin (Dextromethorphan) Dosing and Treatment Approach

For effective cough suppression in adults, use dextromethorphan 60 mg as a single dose, which provides maximum cough reflex suppression—significantly higher than standard over-the-counter dosing of 30 mg that is often subtherapeutic. 1, 2

Recommended Dosing Strategy

Adults and Children ≥12 Years

• Optimal therapeutic dose: 60 mg for maximum cough suppression based on dose-response studies 1, 2
• Standard FDA-approved dosing: 10 mL every 12 hours (not to exceed 20 mL in 24 hours) 3
• Important caveat: Standard OTC dosing is frequently subtherapeutic and may not provide adequate relief 2

Pediatric Dosing (FDA-Approved)

• Ages 6 to <12 years: 5 mL every 12 hours (maximum 10 mL/24 hours) 3
• Ages 4 to <6 years: 2.5 mL every 12 hours (maximum 5 mL/24 hours) 3
• Under 4 years: Do not use 3

Treatment Algorithm

Step 1: First-Line Non-Pharmacologic Approach

• Start with honey and lemon mixtures, which are as effective as pharmacological treatments for benign viral cough 1, 2, 4
• Consider voluntary cough suppression techniques through central modulation 1, 2

Step 2: When Pharmacologic Treatment Is Needed

• Dextromethorphan is the preferred antitussive due to superior safety profile compared to codeine or pholcodine 1, 4
• Use 30-60 mg dosing for adequate therapeutic effect 2, 4
• Dextromethorphan works as a non-sedating opiate that centrally suppresses the cough reflex 1, 4

Step 3: Special Situations

For nocturnal cough disrupting sleep:

• Consider first-generation sedative antihistamines (e.g., chlorpheniramine) which suppress cough and provide beneficial sedation 1, 2, 4

For quick but temporary relief:

• Menthol inhalation provides acute, short-lived cough suppression 1, 2, 4
• Can be prescribed as menthol crystals or proprietary capsules 1

Critical Precautions and Contraindications

Do NOT Use Dextromethorphan When:

• Pneumonia must be ruled out first in patients with tachycardia, tachypnea, fever, or abnormal chest examination findings 1
• Patient has productive cough where secretion clearance is beneficial 2

Important Warnings:

• Exercise caution with combination preparations that contain additional ingredients like paracetamol/acetaminophen, especially at higher doses 1, 2, 4
• Dextromethorphan has limited efficacy for acute cough due to upper respiratory infection according to the American College of Chest Physicians 1

What NOT to Use

Avoid codeine and pholcodine:

• These have no greater efficacy than dextromethorphan 1, 2, 4
• They carry significantly greater adverse effects including drowsiness, nausea, constipation, and physical dependence 1, 2, 4
• Poor benefit-to-risk ratio 2

Common Pitfalls to Avoid

• Using subtherapeutic doses (standard 30 mg) that fail to provide adequate relief when 60 mg is the optimal dose 1, 2
• Prescribing codeine-based antitussives which offer no advantage but increased side effects 2, 4
• Not considering underlying causes in persistent cough (GERD, asthma, upper airway disease) that require specific treatment 1
• Failing to recognize that most acute viral cough is self-limiting (1-3 weeks) and may not require medication 1

When to Consider Alternative Approaches

For postinfectious cough:

• Try inhaled ipratropium before central antitussives 2
• For severe paroxysms, consider prednisone 30-40 mg daily for short period 2

If pertussis suspected:

• Macrolide antibiotics are indicated with 5-day isolation from treatment start 2