What cough medication can be used for a patient with hypertension (high blood pressure) that does not cause drowsiness or further elevate blood pressure?

Cough Medication for Hypertensive Patients Without Drowsiness or Blood Pressure Elevation

For patients with hypertension requiring cough relief without drowsiness or blood pressure elevation, dextromethorphan or guaifenesin are the recommended first-line options, while avoiding sympathomimetic decongestants, codeine, and first-generation antihistamines. 1

Recommended Medications

Dextromethorphan (Preferred for Dry Cough)

• Dextromethorphan is specifically recommended by the American Thoracic Society for cough relief in hypertensive patients as it does not contain sympathomimetic agents that elevate blood pressure and does not cause significant drowsiness 1
• The effective dose is 60 mg, though caution is needed with high doses due to potential combined ingredients in some formulations 1
• This centrally acting antitussive works by suppressing the cough reflex without the sedating effects of codeine or antihistamines 2

Guaifenesin (Preferred for Productive Cough)

• Guaifenesin is an expectorant that loosens mucus without affecting blood pressure or causing drowsiness, making it ideal for hypertensive patients 3, 4
• It is the only legally marketed expectorant in the US per OTC Monograph and has a well-established safety profile 4
• Dosing is 200-400 mg every 4 hours (up to 6 times daily), with extended-release formulations available for 12-hourly dosing 4
• Available in sugar-free and alcohol-free formulations 3

Menthol-Based Preparations (Alternative)

• Menthol preparations suppress the cough reflex when inhaled and provide acute but short-lived relief without blood pressure effects 1
• These are available as menthol crystals or proprietary capsules 1

Medications to Avoid in Hypertensive Patients

Sympathomimetic Decongestants (Absolute Contraindication)

• Any cough preparation containing pseudoephedrine, phenylephrine, or other decongestants must be avoided as these can significantly elevate blood pressure 1
• These sympathomimetic agents are commonly combined with cough suppressants in OTC preparations, so careful label reading is essential 1

Codeine and Opioid-Based Antitussives

• Codeine and pholcodine are not recommended due to their sedating adverse effects and lack of superior efficacy compared to dextromethorphan 1
• Codeine showed no effectiveness over placebo in reducing cough symptoms in clinical trials 5

First-Generation Antihistamines

• Chlorpheniramine and other first-generation antihistamines cause significant drowsiness and should be avoided when non-sedating options are required 6
• Antihistamines were no more effective than placebo in relieving cough symptoms in multiple trials 5

Special Consideration: ACE Inhibitor-Induced Cough

Recognition and Management

• If the patient is taking an ACE inhibitor (like perindopril, lisinopril, or enalapril), this may be the cause of a dry, persistent cough occurring in 5-35% of patients 7, 8, 1
• The only uniformly effective treatment for ACE inhibitor-induced cough is discontinuation of the medication, with cough resolution expected within 1-4 weeks (though may take up to 3 months) 7, 8

Switching Strategy

• The American College of Chest Physicians provides a Grade A recommendation to switch to an angiotensin receptor blocker (ARB) when ACE inhibitor-induced cough occurs 7, 8
• ARBs have cough rates similar to placebo (2-3%) compared to ACE inhibitors (7.9%) while maintaining equivalent cardiovascular benefits 8
• Losartan 25 mg once daily is the most studied ARB for this indication, with titration to 50 mg if needed for blood pressure control 7

Clinical Algorithm

1. First, determine if patient is on an ACE inhibitor: If yes and cough is dry/persistent, discontinue and switch to ARB 7, 8

2. For non-ACE inhibitor cough, select based on cough type:

   • Dry cough: Dextromethorphan 60 mg as needed 1
   • Productive cough: Guaifenesin 200-400 mg every 4 hours 4

3. Verify the formulation contains NO:

   • Decongestants (pseudoephedrine, phenylephrine) 1
   • First-generation antihistamines (chlorpheniramine, diphenhydramine) 1, 6
   • Codeine or other opioids 1

4. Monitor blood pressure after starting any new cough medication to ensure no unexpected elevation 1

Important Caveats

• Many combination OTC cough products contain multiple ingredients including decongestants and antihistamines that should be avoided—always read the complete ingredient list 1
• The evidence for OTC cough medications is limited, with many studies showing conflicting results and unclear clinical significance 5
• If cough persists despite appropriate treatment, investigate underlying causes rather than escalating symptomatic therapy 9