What are suitable cough medications for the elderly?

From the Guidelines

For elderly patients with a cough, I recommend starting with codeine linctus (15 mg/5 mL) or codeine phosphate tablets (15 mg, 30 mg) at a dose of 15-30 mg every 4 hours as required, up to four doses in 24 hours, as this is the most recent and highest quality guideline for managing cough symptoms in the community 1. When considering cough medication for the elderly, it's essential to prioritize their safety and potential for adverse effects.

• The use of codeine is recommended for distressing coughs, with a dose that can be increased up to a maximum of 30-60 mg four times a day (maximum 240 mg in 24 hours) if necessary 1.
• Non-pharmacological approaches such as taking honey, staying hydrated with warm fluids, using a humidifier, and elevating the head while sleeping are also crucial in managing cough symptoms.
• It's vital to avoid cough suppressants in chronic bronchitis and bronchiectasis because they can cause sputum retention, as noted in the guidelines 1.
• Elderly patients should generally avoid combination products containing antihistamines or decongestants, as these can cause confusion, urinary retention, and increased blood pressure.
• Given the potential for drug interactions and the sensitivity of elderly patients to side effects, it's crucial to start with the lowest effective dose and increase cautiously if needed, while also monitoring for potential interactions with their current medications.
• If the cough persists beyond 7-10 days, worsens, or is accompanied by fever, shortness of breath, or chest pain, medical attention should be sought promptly as this could indicate a more serious condition requiring different treatment.

From the FDA Drug Label

Package/Label Principal Display Panel Compare to Delsym® active ingredient Dextromethorphan Polistirex Extended-Release Oral Suspension Cough Suppressant 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

The FDA drug label does not answer the question.

From the Research

Cough Medication for the Elderly

• The most common cause of acute cough in the elderly is respiratory tract infections, which can be viral or bacterial 2.
• Diagnosis of acute cough in the elderly should involve clinical examination, patient history, and tests such as chest X-ray, viral and bacterial culture, and serological testing 2.
• Treatment of acute cough in the elderly may involve specific antibacterial therapy, as well as non-specific antitussive therapy to prevent the adverse effects of repeated coughing 2.
• Dextromethorphan is a commonly used antitussive agent, but its efficacy in treating cough associated with acute upper respiratory tract infection is not well supported by evidence 3.
• In solid-organ transplant recipients, dextromethorphan can be used with caution, but diphenhydramine requires additional monitoring due to its anticholinergic properties and potential interactions with cyclosporine 4.
• Guaifenesin can be used in transplant recipients, but should be used with caution in patients with renal impairment 4.
• Codeine combined with guaifenesin is another option for cough in transplant patients, but those with reduced renal function should be monitored carefully for adverse events 4.

Antitussive Agents

• Dextromethorphan is a safe and effective antitussive agent, but its pharmacokinetics and pharmacodynamics can be affected by genotypic variations in enzymes and interactions with other drugs 5.
• The major metabolic pathways of dextromethorphan include sequential O-demethylation and N-demethylation, yielding dextrorphan, the major active metabolite 5.
• UDP-glucuronosyltranferase produces glucuronide conjugates of dextromethorphan, which can affect its pharmacological and toxicological effects 5.

Analytical Methods

• A gas chromatographic method has been developed for the simultaneous determination of combinations of active ingredients, including dextromethorphan, in cough and cold preparations 6.
• The method involves extraction of the analyte with alkaline ethyl acetate, followed by injection into a gas chromatograph equipped with a fused silica capillary column 6.
• The method is inexpensive, rapid, accurate, and precise, and can be used for routine analysis of tablet and syrup preparations in quality control laboratories of pharmaceutical companies 6.