What to do if a patient on Valsartan (angiotensin II receptor antagonist) develops a dry cough?

Management of Dry Cough in a Patient Taking Valsartan

If a patient on valsartan develops a dry cough, the medication should be continued as ARBs like valsartan do not typically cause cough, and other causes of the cough should be investigated. 1

Understanding ARBs and Cough

Valsartan is an angiotensin II receptor blocker (ARB) that selectively blocks the AT1 receptor. Unlike ACE inhibitors, ARBs do not cause the accumulation of bradykinin and substance P that typically leads to dry cough. Clinical evidence confirms this important distinction:

• In FDA data, the incidence of cough with valsartan is significantly lower (2.6%) compared to ACE inhibitors (7.9%) 1
• In a specific trial of patients with a history of ACE inhibitor-induced cough, only 19.5% of patients on valsartan developed cough compared to 68.9% on lisinopril 2

Diagnostic Algorithm

1. Rule out ARB as cause of cough:

   • ARBs like valsartan rarely cause cough and are actually recommended as alternatives for patients who develop cough on ACE inhibitors 3, 4
   • The incidence of cough with ARBs is similar to that of placebo or control drugs 3

2. Investigate other causes of cough:

   • Respiratory infections
   • Asthma or COPD exacerbation
   • Gastroesophageal reflux disease
   • Post-nasal drip
   • Heart failure exacerbation

3. If no other cause is identified and cough persists:

   • Consider a challenge/re-challenge test to definitively determine if valsartan is the cause 5

Management Recommendations

If valsartan is confirmed as the cause (uncommon scenario):

1. Consider switching to another ARB:

   • Some evidence suggests variation in cough incidence between different ARBs 5
   • Options include candesartan (4-8 mg initially, target 32 mg daily) or losartan (25-50 mg initially, target 50-100 mg daily) 3

2. If cough persists with multiple ARBs:

   • Consider alternative antihypertensive classes based on comorbidities
   • For heart failure patients: hydralazine/isosorbide dinitrate combination may be considered, especially in those of African-American descent 3

If valsartan is NOT the cause (more likely scenario):

1. Continue valsartan at the current effective dose
2. Treat the underlying cause of the cough based on diagnosis
3. Monitor blood pressure to ensure continued efficacy

Important Considerations

• ARBs are specifically recommended for patients who develop cough on ACE inhibitors (Grade A recommendation) 3
• In a direct comparison study, patients with prior ACE inhibitor-induced cough had similar rates of cough on valsartan (19.5%) as on hydrochlorothiazide (19.0%), but significantly less than on lisinopril (68.9%) 2
• If the patient has heart failure, maintaining RAAS blockade is particularly important for mortality benefit, making ARBs the preferred alternative to ACE inhibitors 3

Pitfalls to Avoid

• Don't automatically assume valsartan is causing the cough - this is a common misconception that confuses ARBs with ACE inhibitors
• Don't discontinue beneficial RAAS blockade without confirming the cause of cough
• Don't miss heart failure exacerbation as a potential cause of new-onset cough in patients on cardiovascular medications

By following this approach, you can ensure appropriate management while maintaining the cardiovascular benefits of RAAS blockade that valsartan provides.