What alternative blood pressure medication can be used for patients on lisinopril (angiotensin-converting enzyme inhibitor) who require indomethacin (nonsteroidal anti-inflammatory drug)?

Alternative Blood Pressure Medication for Patients on Lisinopril Who Require Indomethacin

Angiotensin Receptor Blockers (ARBs) are the most appropriate alternative blood pressure medication for patients who need to switch from lisinopril when indomethacin therapy is required. 1

Rationale for Drug Interaction Concern

Indomethacin, a nonsteroidal anti-inflammatory drug (NSAID), can significantly reduce the antihypertensive efficacy of ACE inhibitors like lisinopril. This interaction occurs because:

• NSAIDs inhibit prostaglandin synthesis, which counteracts the blood pressure-lowering effects of ACE inhibitors 2
• Studies show that when indomethacin is given with lisinopril, there is a reduced antihypertensive effect 3
• NSAIDs can cause sodium retention and peripheral edema, further compromising blood pressure control 2

Best Alternative Medication Choice

When switching from lisinopril due to indomethacin therapy, the following algorithm should guide decision-making:

First-line Alternative: Angiotensin Receptor Blockers (ARBs)

• ARBs (such as losartan, valsartan, or candesartan) are the most appropriate choice 1
• ARBs provide similar cardiovascular protection as ACE inhibitors but through a different mechanism
• ARBs are more effective in reducing cardiovascular events, particularly stroke, compared to beta-blockers 1

Second-line Alternatives:

1. Calcium Channel Blockers (dihydropyridine class):

   • Amlodipine is particularly well-suited as it has minimal interaction with NSAIDs 2
   • Dihydropyridine CCBs have been shown to be safe and effective in hypertension management 2

2. Thiazide or Thiazide-like Diuretics:

   • Chlorthalidone (12.5-25 mg daily) is preferred over hydrochlorothiazide due to superior outcomes 1
   • Should be used with caution as NSAIDs may reduce diuretic efficacy

Medications to Avoid

Several antihypertensive medications should be avoided when using indomethacin:

• ACE inhibitors (like lisinopril): Significant reduction in antihypertensive effect when combined with NSAIDs 3
• Non-dihydropyridine calcium channel blockers (diltiazem, verapamil): May cause negative inotropic effects 2
• Beta-blockers: May have reduced efficacy with NSAIDs and can worsen peripheral vascular disease 2

Implementation Approach

1. Initiate ARB therapy:

   • Start with losartan 50 mg daily or valsartan 80-160 mg daily
   • Allow 4 weeks to observe full response before dose adjustment 2

2. Monitor closely:

   • Check blood pressure within 1 month of medication change 1
   • Monitor renal function and electrolytes 2-4 weeks after starting therapy 1
   • Assess for signs of fluid retention which may be exacerbated by indomethacin

3. Consider combination therapy if needed:

   • If blood pressure remains uncontrolled, add a dihydropyridine calcium channel blocker like amlodipine 2
   • The combination of ARB + calcium channel blocker has shown good efficacy and tolerability 4

Special Considerations

• For patients with diabetes or albuminuria, ARBs are particularly beneficial 1
• For patients with heart failure, careful monitoring is required as both indomethacin and certain antihypertensives can affect cardiac function 2
• Elderly patients may require lower initial doses and more gradual titration 1

By following this approach, clinicians can effectively manage hypertension in patients requiring indomethacin while minimizing adverse drug interactions and maintaining cardiovascular protection.