What is the next best step for a patient with hypertension who is currently taking Amlodipine (Norvasc) 10mg, Losartan 100mg, and Furosemide (Lasix) 20mg and remains hypertensive?

Management of Resistant Hypertension in a Patient on Triple Therapy

The next best step for this patient is to add spironolactone as a fourth antihypertensive agent to the current regimen of amlodipine, losartan, and furosemide. 1

Current Medication Assessment

The patient is currently on:

• Amlodipine (Norvasc) 10mg - maximum dose of a dihydropyridine calcium channel blocker
• Losartan 100mg - maximum dose of an angiotensin receptor blocker
• Furosemide (Lasix) 20mg - a loop diuretic at a relatively low dose

This combination represents three different classes of antihypertensive medications at optimized doses (except for furosemide which could be increased), yet the patient remains hypertensive, meeting the definition of resistant hypertension.

Next Steps in Medication Management

Adding a Fourth Agent

According to the 2020 International Society of Hypertension guidelines, the recommended next step after a patient remains hypertensive on an ARB, CCB, and diuretic is to add spironolactone 1. The guideline specifically states:

1. For non-black patients, the progression should be:
   • ARB/ACEI (patient is on losartan)
   • Add DHP-CCB (patient is on amlodipine)
   • Add thiazide/thiazide-like diuretic (patient is on furosemide instead)
   • Add spironolactone or, if not tolerated or contraindicated, consider amiloride, doxazosin, eplerenone, clonidine, or beta-blocker

Alternative Considerations

Optimizing Current Therapy

Before adding a fourth agent, ensure:

• Medication adherence is confirmed
• Proper BP measurement technique is used
• Lifestyle modifications are optimized (sodium restriction, physical activity, weight management)

Diuretic Optimization

• Consider replacing furosemide 20mg with a thiazide-like diuretic (chlorthalidone or indapamide)
• Furosemide has a shorter duration of action and may not provide 24-hour BP control
• If keeping furosemide, consider increasing the dose as the current 20mg is relatively low 2

Monitoring and Follow-up

After adding spironolactone:

• Monitor serum potassium and renal function within 7-14 days of initiation
• Follow up within 2-4 weeks to assess blood pressure response
• Target blood pressure should be <130/80 mmHg 1, 3
• If BP remains uncontrolled after optimization of 4-drug therapy, consider referral to a hypertension specialist

Important Considerations and Precautions

When Adding Spironolactone

• Start at a low dose (12.5-25mg daily)
• Monitor for hyperkalemia, especially since the patient is already on an ARB
• Check for contraindications (severe renal impairment, hyperkalemia)
• Be aware of potential side effects (gynecomastia in males, menstrual irregularities in females)

Special Populations

• If the patient is black, ensure optimal dosing of the calcium channel blocker and diuretic before adding spironolactone 1
• For elderly patients, titrate doses more gradually and monitor for orthostatic hypotension 3

Conclusion

Adding spironolactone as a fourth agent is the evidence-based next step for this patient with resistant hypertension who is already on maximum doses of an ARB and CCB along with a loop diuretic. This approach is supported by current hypertension guidelines and offers the best chance of achieving blood pressure control while minimizing adverse effects.