What is the alternative medication for a patient with Hypertension (HTN) on Captopril (Angiotensin-Converting Enzyme inhibitor) complaining of a dry cough?

Management of ACE Inhibitor-Induced Cough in Hypertension

Losartan (D) is the appropriate alternative medication for a patient with hypertension on captopril who is experiencing dry cough. 1, 2

Understanding ACE Inhibitor-Induced Cough

ACE inhibitor-induced cough is a well-documented class effect that occurs in approximately 5-35% of patients taking these medications. The cough is typically:

• Dry and non-productive
• Associated with a tickling or scratching sensation in the throat
• Not dose-dependent
• More common in women, nonsmokers, and persons of Chinese origin
• May occur within hours of the first dose or be delayed for weeks to months 1

Why Losartan is the Correct Choice

Angiotensin receptor blockers (ARBs) like losartan are the recommended alternative for patients who develop cough on ACE inhibitors for several reasons:

1. The American College of Chest Physicians provides a Grade A recommendation for switching to an ARB when ACE inhibitor-induced cough occurs 1
2. ARBs do not inhibit ACE and therefore do not cause the accumulation of bradykinin and substance P that leads to cough 1
3. Clinical trials demonstrate that the incidence of cough with losartan is similar to placebo or hydrochlorothiazide, and significantly lower than with ACE inhibitors 2
4. In comparative trials, losartan has shown similar blood pressure lowering efficacy to ACE inhibitors like enalapril but without the high incidence of dry cough 3

Why Other Options Are Not Appropriate

• Atenolol (A): A beta-blocker that does not address the mechanism of ACE inhibitor-induced cough and represents a completely different class of antihypertensives
• Enalapril (B): Another ACE inhibitor that would likely cause the same cough as captopril since this is a class effect 1
• Nifedipine (C): A calcium channel blocker that, while it may be used as an alternative antihypertensive, is not specifically recommended for ACE inhibitor-induced cough. Some evidence suggests calcium channel blockers might attenuate ACE inhibitor cough but not eliminate it 1

Management Algorithm

1. Confirm ACE inhibitor as cause of cough:

   • Discontinue captopril regardless of temporal relationship between drug initiation and cough onset
   • Cough typically resolves within 1-4 weeks of discontinuation (may take up to 3 months in some cases) 1

2. Switch to losartan:

   • Initial dose of losartan 50 mg daily
   • Monitor blood pressure to ensure continued efficacy 2
   • FDA data shows incidence of cough with losartan is significantly lower than with ACE inhibitors 2

3. Monitor for resolution of cough:

   • Most patients experience complete resolution of cough after switching to an ARB
   • In rare cases where cough persists with losartan, consider alternative ARBs or other antihypertensive classes 4

Important Clinical Considerations

• While rare, there have been isolated case reports of cough with ARBs like losartan, but this is exceptionally uncommon 5
• The incidence of cough with ACE inhibitors is higher in patients with heart failure (26%) compared to those with hypertension (14%) 6
• If maintaining RAAS blockade is particularly important for the patient (e.g., in heart failure or diabetic nephropathy), ARBs provide similar benefits without the cough side effect 4

By switching from captopril to losartan, you maintain effective blood pressure control while eliminating the troublesome dry cough that significantly impacts patient quality of life and medication adherence.