What are effective antitussive (anti-cough) medications in tablet form for adults?

From the Guidelines

For adults with a cough, I recommend over-the-counter medications containing dextromethorphan, such as Robitussin DM, Delsym, or Mucinex DM, as the first line of treatment. Dextromethorphan works as a cough suppressant by affecting the part of your brain that triggers the cough reflex, making it effective for dry, hacking coughs 1. The typical adult dose is 10-30 mg every 4-8 hours, not exceeding 120 mg in 24 hours.

Key Considerations

• Dextromethorphan has been shown to be more effective than codeine in controlling cough, including in patients with lung cancer 1.
• If the cough persists or is severe, opioids such as pholcodine or hydrocodone may be considered, but their use should be guided by a healthcare provider due to potential side effects and risks 1.
• It's essential to note that the choice of treatment may be dictated by availability rather than pharmacologic parameters, and local anesthetics like nebulized lidocaine may be tried when other pharmacologic approaches have failed to manage cough 1.

Important Warnings

• If your cough persists beyond 7 days, is accompanied by fever over 101°F, produces discolored phlegm, or causes difficulty breathing, you should consult a healthcare provider as these symptoms may indicate a more serious condition requiring prescription medication.
• Take these medications with plenty of water, and avoid alcohol while using them.

From the FDA Drug Label

Directions • shake bottle well before use • measure only with dosing cup provided • do not use dosing cup with other products • dose as follows or as directed by doctor adults and children 12 years of age and over 10 mL every 12 hours, not to exceed 20 mL in 24 hours Package/Label Principal Display Panel Compare to Delsym® active ingredient Dextromethorphan Polistirex Extended-Release Oral Suspension Cough Suppressant

The FDA drug label does not answer the question.

From the Research

Cough Medicines for Adults

• Dextromethorphan is a commonly used antitussive for the treatment of cough associated with acute upper respiratory tract infection 2.
• A combination of bilastine, dextromethorphan, and phenylephrine is expected to provide non-sedating treatment for cough associated with a common cold or allergy 3.
• Antitussive preparations which are available as combinations of codeine or dextromethorphan with antihistamines, decongestants and expectorants can provide effective symptomatic relief of dry or non-productive cough 4.
• 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 4.

Efficacy of Cough Medicines

• Dextromethorphan may modestly decrease cough in adults compared with placebo 5.
• Bilastine/dextromethorphan/phenylephrine combination syrup is efficacious, safe, non-sedating, and non-inferior to Alex® syrup in the treatment of acute dry cough due to a common cold or allergy 3.
• A single 30 mg dose of dextromethorphan provides very little if any support for clinically significant antitussive activity in patients with cough associated with acute upper respiratory tract infection 2.
• Dextromethorphan may be effective for cough in older children and adults, and guiafenesin (an expectorant) showed mixed benefit in two trials 6.

Available Options

• Codeine and chlorpheniramine combination is effective in the management of dry cough 4.
• Dextromethorphan is available as an over-the-counter medication for cough 5, 6.
• Bilastine, dextromethorphan, and phenylephrine syrup is a non-sedating treatment option for cough associated with a common cold or allergy 3.