What alternative antihypertensive medication can be prescribed for a patient on a Calcium Channel Blocker (CCB) who develops a cough?

Management of ACE Inhibitor-Induced Cough in a Patient on Calcium Channel Blocker

For a patient who develops a cough while on an ACE inhibitor and is also taking a calcium channel blocker (CCB), an angiotensin receptor blocker (ARB) should be prescribed as the alternative antihypertensive medication.

Understanding ACE Inhibitor-Induced Cough

• ACE inhibitor-induced cough is a common side effect that does not always require treatment discontinuation, but when troublesome (e.g., disrupting sleep), substitution with an ARB is recommended 1
• The cough associated with ACE inhibitors is typically dry, nonproductive, and often worse at night 2
• Clinical trials have demonstrated that the incidence of cough with ARBs is similar to that of placebo or hydrochlorothiazide, making ARBs an appropriate alternative for patients who experience ACE inhibitor-induced cough 3

Recommended Approach

Step 1: Confirm ACE Inhibitor as Cause of Cough

• Rule out other causes of cough such as pulmonary edema, which can be a symptom of heart failure 1
• Determine if the cough is troublesome enough to warrant medication change (e.g., disrupting sleep or daily activities) 1

Step 2: Select an ARB as the Alternative Treatment

• ARBs are the preferred alternative for patients with ACE inhibitor-induced cough 1
• Common ARB options include:
  • Losartan: Starting dose 4-8 mg once daily, target dose up to 100 mg daily 1
  • Valsartan: Starting dose 40 mg twice daily, target dose 160 mg twice daily 1
  • Candesartan: Starting dose 4-8 mg once daily, target dose 32 mg once daily 1

Step 3: Initiation and Monitoring

• Check renal function and electrolytes before starting an ARB 1
• Start with a low dose and titrate upward every 2-4 weeks as tolerated 1
• Re-check blood chemistry 1-2 weeks after initiation and 1-2 weeks after final dose titration 1
• Monitor for potential side effects including hypotension, hyperkalemia, and worsening renal function 1

Special Considerations

Continuing the Calcium Channel Blocker

• The patient can continue their CCB along with the newly prescribed ARB, as this is a recognized effective combination for hypertension management 1
• CCBs and ARBs are frequently used together as a two-drug combination for hypertension management 1

Potential Contraindications for ARBs

• ARBs should be used with caution in patients with:
  • Significant renal dysfunction (creatinine >2.5 mg/dL or eGFR <30 mL/min) 1
  • Hyperkalemia (K+ >5.0 mmol/L) 1
  • Pregnancy (contraindicated) 1
  • Bilateral renal artery stenosis 1

Rare Cases of ARB-Induced Cough

• Although uncommon, there have been isolated case reports of cough associated with ARBs 4
• If cough persists after switching to an ARB, consider other antihypertensive options such as CCBs (if not already on maximum dose), thiazide diuretics, or beta-blockers 1

Alternative Options if ARBs are Contraindicated

• Increase the dose of the current CCB if not at maximum effective dose 1
• Add a thiazide diuretic if additional blood pressure control is needed 1
• Consider a beta-blocker, particularly in patients with concomitant coronary artery disease or heart failure 1

Remember that some ACE inhibitor-induced cough resolves with time, so if the cough is mild, continuing the current regimen with close monitoring may be appropriate 1.