What is the treatment for cough?

From the Guidelines

Cough medicine can help alleviate symptoms of cough due to various causes, and for a dry, non-productive cough, dextromethorphan (found in Robitussin DM, Delsym) is recommended at 10-30mg every 4-6 hours for adults, as supported by studies such as 1 and 2. For wet, productive coughs, guaifenesin (Mucinex) at 200-400mg every 4 hours can help thin mucus. Combination products like Robitussin DM contain both ingredients. For nighttime cough relief, products containing diphenhydramine (like NyQuil) can be helpful. Most cough medicines should be used for no more than 7 days. If coughing persists beyond a week, is severe, or is accompanied by fever, shortness of breath, or bloody mucus, medical attention should be sought, as emphasized in guidelines such as 3 and 4. Cough suppressants work by blocking the cough reflex in the brain, while expectorants increase fluid secretions in the respiratory tract to thin mucus. Staying hydrated, using a humidifier, and avoiding irritants like smoke can complement medication use, as suggested in studies like 5. Children under 4 should not be given OTC cough medicines without medical advice. Some studies, such as 6, also suggest that opioids like hydrocodone and dihydrocodeine can be effective in suppressing cough in patients with lung cancer, but these should only be used under medical supervision. It's essential to note that the management of cough should be tailored to the underlying cause, and in some cases, such as chronic bronchitis or lung cancer, specific treatments may be necessary, as outlined in guidelines like 2 and 6. Overall, the approach to managing cough should be empiric and integrative, considering the patient's medical history, physical examination, and potential underlying causes, as recommended in 3 and 4.

From the FDA Drug Label

USES Helps loosen phlegm (mucus) and thin bronchial secretions to make coughs more productive. Purpose Cough suppressant Uses temporarily relieves • cough due to minor throat and bronchial irritation as may occur with the common cold or inhaled irritants • the impulse to cough to help you get to sleep There are two types of cough medicine:

• Expectorant: Guaifenesin helps loosen phlegm and thin bronchial secretions to make coughs more productive 7.
• Cough suppressant: Dextromethorphan temporarily relieves cough due to minor throat and bronchial irritation [8] [9].

From the Research

Effectiveness of Cough Medicines

• The effectiveness of over-the-counter (OTC) cough medicines for acute cough in children and adults is uncertain, as stated in studies 10, 11, 12, 13.
• These studies found that there is no good evidence for or against the effectiveness of OTC medicines in acute cough.

Types of Cough Medicines

• Antitussives: codeine was no more effective than placebo in reducing cough symptoms, while dextromethorphan showed variable results 10, 11, 12, 13.
• Expectorants: guaifenesin showed significant benefit in one study, but not in others 10, 11, 12, 13.
• Mucolytics: reduced cough frequency and symptom scores in some studies 10, 11, 12, 13.
• Antihistamine-decongestant combinations: showed conflicting results 10, 11, 12, 13.
• Antihistamines: were no more effective than placebo in relieving cough symptoms 10, 11, 12, 13.

Adverse Effects

• Adverse effects were reported in some studies, including nausea, vomiting, headache, and drowsiness 10, 11, 12, 13.
• The incidence of adverse effects was generally low, but higher in participants taking preparations containing antihistamines and dextromethorphan 11.

Limitations of Studies

• The number of studies in each category of cough preparations was small, making it difficult to draw conclusions 10, 11, 12, 13.
• Studies often showed conflicting results, and the quality of the studies was variable 10, 11, 12, 13.
• Higher quality evidence is needed to determine the effectiveness of self-care treatments for acute cough 10, 11, 12, 13.