What is a suitable cough suppressant for aiding sleep?

Cough Suppressant for Sleep

For nighttime cough disrupting sleep, use dextromethorphan 30-60 mg at bedtime as the first-line pharmacological option, or consider first-generation sedating antihistamines specifically for their dual cough suppression and sleep-promoting effects. 1, 2

First-Line Approach for Nocturnal Cough

Non-Pharmacological Options

• Simple home remedies like honey and lemon should be tried first, as they may be as effective as pharmacological treatments for benign viral cough and are the simplest, cheapest option. 1, 2
• Honey has been shown to be superior to no treatment for cough frequency and sleep difficulty in children, and this approach is reasonable for adults as well. 3

Pharmacological First-Line: Dextromethorphan

• Dextromethorphan is the recommended first-line antitussive agent due to its superior safety profile compared to opioid alternatives. 1, 4
• For optimal nighttime cough suppression, use 30-60 mg at bedtime, as standard over-the-counter dosing is often subtherapeutic and maximum cough reflex suppression occurs at 60 mg. 1, 2
• The typical dosing range is 10-15 mg three to four times daily, with a maximum daily dose of 120 mg, but a single bedtime dose of 60 mg provides prolonged suppression ideal for sleep. 5, 1
• Caution: Check combination products carefully to avoid excessive amounts of other ingredients like acetaminophen when using higher doses. 1

Alternative First-Line: Sedating Antihistamines

• First-generation sedating antihistamines are particularly suitable for nocturnal cough because they both suppress cough and cause drowsiness, addressing both the cough and sleep disruption simultaneously. 1, 2
• This option is especially useful when the primary complaint is sleep disruption rather than cough severity alone. 1

Second-Line and Additional Options

Menthol Inhalation

• Menthol suppresses the cough reflex when administered by inhalation and provides acute but short-lived relief. 1, 2
• Can be prescribed as menthol crystals or proprietary capsules for quick but temporary relief before bedtime. 2

What NOT to Use

• Codeine is NOT recommended despite being widely researched, as it has no greater efficacy than dextromethorphan but has a much worse adverse side effect profile including drowsiness, nausea, constipation, and risk of physical dependence. 1, 2, 6
• Codeine is less preferred even in palliative care settings compared to other opioid derivatives. 5

Special Considerations for Bedtime Dosing

Palliative Care Context

• For patients with advanced lung cancer in the palliative stage, a bedtime dose of codeine/pholcodine or morphine may help suppress cough and induce undisturbed sleep, though this is based on clinical experience rather than evidence. 5
• For patients already on opioids, increasing the morphine dose by 20% at bedtime may be helpful. 5

Duration and Follow-Up

• Cough lasting more than 3 weeks requires a full diagnostic workup rather than continued antitussive therapy to evaluate for alternative diagnoses. 1
• Dextromethorphan should be used for short-term symptomatic relief only. 1

Common Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (standard OTC doses of 10-15 mg may not provide adequate nighttime relief). 1, 6
• Prescribing codeine-based products which have no efficacy advantage but increased side effects. 1, 2, 6
• Not considering simple remedies first like honey and lemon, which may be equally effective without side effects. 1, 2
• Using dextromethorphan for productive cough where clearance of secretions is beneficial. 1, 6

Practical Algorithm for Nocturnal Cough

1. Start with honey and lemon mixture at bedtime for benign viral cough. 1, 2
2. If additional relief needed, add dextromethorphan 30-60 mg at bedtime for optimal suppression. 1, 2
3. For patients where sleep disruption is the primary concern, consider first-generation antihistamines for dual cough suppression and sedation. 1, 2
4. Avoid codeine-containing products due to poor benefit-to-risk ratio. 1, 2, 6
5. Reassess if cough persists beyond 3 weeks for underlying causes requiring specific treatment. 1