From the Guidelines
For a cough, the most effective treatment is to start with over-the-counter cough syrups containing dextromethorphan, such as Robitussin DM or Delsym, at a dose of 10-30 mg every 4-8 hours as needed, not exceeding 120 mg in 24 hours, as recommended by the most recent and highest quality study 1.
Recommended Treatment
- The recommended dose for dextromethorphan is 10-30 mg every 4-8 hours as needed, not exceeding 120 mg in 24 hours.
- For patients who do not respond to this approach, opioids such as pholcodine or hydrocodone may be considered next, as suggested by the study 1.
- The use of local anesthetics, such as nebulized lidocaine, may also be helpful in case of intractable cough that has not responded to other approaches, as supported by the study 1.
Important Considerations
- Most coughs from common colds or minor respiratory infections should improve within 7-10 days; if the cough persists longer, is severe, or is accompanied by high fever, difficulty breathing, or bloody mucus, a healthcare provider should be consulted.
- Cough suppressants like dextromethorphan work by blocking the cough reflex in the brain, while expectorants like guaifenesin help thin mucus to make coughs more productive.
- Staying hydrated and using a humidifier can complement medication by keeping airways moist, as suggested by the study 1.
Additional Options
- Other over-the-counter cough syrups, such as those containing guaifenesin (like Mucinex), may also be effective, but the evidence is less strong, as noted in the study 1.
- The use of benzonatate, a peripherally acting antitussive, may be effective in controlling cough in some patients, as reported in the study 1.
From the FDA Drug Label
Helps loosen phlegm (mucus) and thin bronchial secretions to make coughs more productive. The recommended treatment for a cough using cough syrup is to use it to loosen phlegm (mucus) and thin bronchial secretions to make coughs more productive 2.
- Key benefits: Helps make coughs more productive
- Important considerations:
- Ask a doctor before use if you have a cough that occurs with too much phlegm (mucus) or a chronic cough
- Stop use and ask a doctor if cough lasts more than 7 days or is accompanied by fever, rash, or persistent headache 2
From the Research
Cough Syrup Treatment
The recommended treatment for a cough using cough syrup depends on the type of cough and its cause.
- For dry coughs, antitussive preparations such as codeine or dextromethorphan with antihistamines, decongestants, and expectorants can provide symptomatic relief 3.
- First-generation antihistamines like chlorpheniramine and centrally acting opioid derivatives like codeine are often used alone or in combination in the management of nonspecific cough 3.
- For productive coughs, expectorants can help loosen mucus, while suppressants can help relieve dry coughs 4.
Types of Cough Syrups
Different types of cough syrups are available, including:
- Antitussive preparations that contain codeine or dextromethorphan with antihistamines, decongestants, and expectorants 3.
- Combinations of bilastine, dextromethorphan, and phenylephrine that provide non-sedating treatment for cough associated with a common cold or allergy 5.
- Cough syrups that contain dextromethorphan, which can provide some relief for adults with acute upper respiratory infections (URIs) 6.
Safety and Efficacy
The safety and efficacy of cough syrups can vary depending on the ingredients and the individual patient.
- Dextromethorphan can be abused by adolescents, who may take large doses to self-intoxicate, leading to profound psychological and physiological effects 7.
- Bilastine, dextromethorphan, and phenylephrine combination syrup has been shown to be efficacious, safe, and non-sedating in the treatment of acute dry cough due to a common cold or allergy 5.
- Honey may modestly decrease the frequency and severity of cough in children compared to dextromethorphan or no treatment 6.