Resistant Hypertension: When High Blood Pressure is Hard to Control
Evidence-based Care Processes Consistent with Best Practices
Resistant hypertension is defined as uncontrolled blood pressure while taking 3 or more drugs for high blood pressure. This is a common problem. About 20% of Americans with high blood pressure have resistant hypertension. Since high blood pressure is the leading risk factor for years of life lost, this is a very important problem and we can do much better.
The most common 3-drug combination taken in patients who have resistant hypertension is an ACE inhibitor like lisinopril, a beta blocker like metoprolol, and a fluid pill like hydrochlorothiazide. That is part of the reason these patients have resistant hypertension. Lisinopril and hydrochlorothiazide are appropriate, but ACE inhibitors and metoprolol do not work well together. That combination is ineffective. The most effective three drug combination is an ACE inhibitor like lisinopril (ends with pril) or an ARB like losartan (ends with sartan), a calcium channel blocker like amlodipine (does not increase heart rate), and a thiazide-type diuretic like chlorthalidone or indapamide. The fourth drug added to control resistant hypertension should be spironolactone or eplerenone. Despite the clear advantages of this carefully designed protocol for hypertension, only 3% of US adults with resistant hypertension were taking a thiazide-like diuretic (chlorthalidone or indapamide) and only 9% were taking spironolactone or eplerenone. There is a huge opportunity for improvement.
The choice of medications makes a huge difference. Achieving a blood less than 140/90 ranged from 54% among those taking a combination of losartan, amlodipine, and metoprolol to 76.0% among their counterparts taking lisinopril, amlodipine, and hydrochlorothiazide. That is a huge difference in efficacy. According to the most recent guidelines, the first step in the management of resistant hypertension is to substitute a thiazide-like diuretic such as chlorthalidone or indapamide for a thiazide diuretic to achieve BP control. These medications have a longer duration of action than hydrochlorothiazide and are therefore more effective in lowering the blood pressure. They may not be used frequently because practicing physicians have learned that they cause more problems. Chlorthalidone was associated with almost three times the risk of a low potassium level, 1.3 times the risk of low sodium, 1.4 times the risk of acute renal failure, along with small increases in the risk of chronic kidney disease, and type 2 diabetes mellitus.
As a practical matter, how do you combine all this information to construct a best practice protocol to manage high blood pressure.
1. The first drug should be a drug like lisinopril or losartan.
2. Next to add is amlodipine. Amlodipine is superior to other drugs in this class because it does not cause a rapid heart rate and it has antioxidant effects.
3. The next drug is hydrochlorothiazide. It is not as effective as chlorthalidone or indapamide, but it has fewer side effects.
4. The fourth drug should be spironolactone or eplerenone.
One of the first three drugs should be a fluid pill like hydrochlorothiazide, chlorthalidone, indapamide, or a more powerful diuretic like furosemide. Getting rid of excess salt and water is a big part of treatment with patients who have high blood pressure. Giving a fluid pill always increases aldosterone production which causes low potassium levels. High aldosterone production also occurs in overweight patients and is part of the reason heavy people have high blood pressure. The most prudent was to control the blood pressure is to use a lighter dose and lower strength fluid pill in combination with spironolactone or eplerenone to block the effects of aldosterone. If you must use chlorthalidone to control the pressure, it is even more important to block the effects of the more intense stimulation of aldosterone.
Using a protocol for high blood pressure is easy, but constructing an evidence-based protocol with careful consideration of drug interactions, drug efficacy, and medication side effects requires careful consideration. You can control your pressure safely and with minimal side effects. Be sure you are receiving this type of treatment. Controlling resistant hypertension is essential for your continued health and safety.
We need to do better. Thank you for this insight will share.