CorrectCare

Evidence-based Medicine
Prescribing Antihypertensives: Vanilla or Mocha Deluxe?

By Jeffrey Keller, MD

I have a friend who once owned an ice cream truck. He would drive around neighborhoods in the summer selling ice cream to kids. He told me that he sold much more ice cream if he offered only three flavors: chocolate, vanilla and strawberry.

I thought, “That can’t be true. Surely you would sell more ice cream if you offered more flavors.”

But my friend said that when he did offer a lot of flavors, the kids couldn’t decide which kind of ice cream to buy. They would stand by his ice cream truck for a seemingly endless amount of time, paralyzed by indecision. At the end of the day, he sold less ice cream.

This story is a great analogy for the situation that confronts medical practitioners who treat hypertension. We face too many choices. Should we use a diuretic, a beta-blocker, an ACE inhibitor, a calcium channel blocker, an angiotensin blocker or a peripheral vasodilator? Are any of these categories more effective than the others? Which have the fewest side effects? Angiotensin blockers are 15 times more expensive than ACE inhibitors; are they 15 times more effective?

This can quickly become complicated. Like kids buying ice cream, we can become paralyzed by indecision. All too frequently, we defer the decision to whatever good-looking drug rep has most recently bought us pizza and we use their medication.

Head-to-Head Comparison
A comprehensive course in antihypertensive pharmacology would go through all of these categories of medications in detail, but that literally would take weeks. Fortunately, we are spared that exercise because of ALLHAT. Shorthand for the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, this was a truly landmark study that should change your practice. (The results were published in the Journal of the American Medical Association, Dec. 18, 2002.) ALLHAT makes hypertensive prescribing easy.

First, let me give some background and then briefly describe the study itself. Almost all new blood pressure medications are studied in comparison to placebo. All of the blood pressure medications on the market today work better at lowering high blood pressure than sugar pills. These drugs are then marketed to us as effective blood pressure agents.

As a result of this marketing, prescriptions for older, traditional medications, such as diuretics and beta-blockers, fell nationwide, while use of the newer agents, such as calcium channel blockers and adrenergic blockers, rose.

The fatal flaw in this system is that new blood pressure medications are rarely compared head-to-head to the older (and less profitable) medications. No one knew which of the many hypertensive agents available were more effective at lowering blood pressure or at reducing heart disease.

ALLHAT was designed to do this comparison. The study compared four blood pressure medications: a diuretic, a calcium channel blocker, an adrenergic blocker and an ACE inhibitor. The double-blind study took place over 10 years and included a whopping 42,000 patients.

Recommended Therapy
And here is the result: The blood pressure medication most effective at reducing complications of heart disease in hypertensive patients is ... (drum role) ... DIURETICS. Patients using the study diuretic (chlorthalidone) had better blood pressure control and were much less likely to suffer from cardiovascular disease events than patients taking any of the other drugs.

The adrenergic blocker (doxazocin) was the worst—in fact, its use was discontinued midway through the study. The ACE inhibitor (lisinopril) and the calcium channel blocker (amlodipine) were better than doxazocin, but clearly inferior to chlorthalidone.

Who knew? The cheapest and simplest of the available agents is the one that we should be using most.

I don’t know about you, but it always tickles me when the cheapest form of therapy turns out also to be the best evidence-based therapy. Thiazides cost a couple of cents per pill. The less-effective blood pressure medications often cost as much as $1.50 per pill.

The ALLHAT recommendations are as follows:
1. Thiazide diuretics are better than other blood pressure medications in preventing heart disease. Diuretics should be the first-line blood pressure medication for almost every patient.
2. For patients currently taking a different antihypertensive, they and their medical provider should consider switching to a diuretic—even if their blood pressure is well-controlled.
3. Most hypertensive patients will require more than one medicine to control their blood pressure. One of those medications should be a diuretic.

Three-Step Approach
So how should we use this information to provide cost-effective, evidence- based treatment for the initial treatment of hypertension in our jails and prisons? For my jails, it is a simple, three-step process:
1. We educate hypertensive inmates about lifestyle modifications they should make to lower their blood pressure—stuff like losing weight and exercising.
2. The first drug we prescribe for almost everybody is a diuretic. We use hydrochlorothiazide.
3. If a second drug is needed, we choose it based on the patient’s underlying disease process.

• If the patient has diabetes or coronary artery disease, we usually will prescribe an ACE inhibitor along with the diuretic. We like enalopril and benazepril because they are significantly cheaper than other ACE inhibitors and because they are taken only once a day.
• If the patient has angina, we may use a beta-blocker. Again, we like the less expensive, once-daily beta-blockers like atenolol or metoproplol.
• Since ACE inhibitors and beta-blockers tend not to work as well with black patients, with these patients we may use a calcium-channel blocker, such as generic diltiazem or nifedipine.

Many resources are available to guide you in developing your own treatment protocols. I have found these to be the most helpful:

1. The NCCHC clinical guideline for treatment of hypertension does not address drug therapy, but it is excellent for deciding whom to treat and how best to follow them.
2. “The Initial Treatment of Hypertension,” published by the Medical Letter, makes treatment recommendations based on ALLHAT and similar studies and also compares costs of the various available agents.
3. The NIH National Heart, Lung, and Blood Institute has prepared an ALLHAT Quick Reference for Health Care Providers.

I have a final recommendation. Once you have used this information to develop new policies and procedures for the treatment of hypertension in your facilities, treat yourself to some ice cream.

— About the author:  Jeffrey Keller, MD, is president of Badger Correctional Medicine, a contract management company based in Idaho Falls, ID. Reach him by e-mail at badgermed@datawav.net.

[This article first appeared in the Spring 2005 issue of CorrectCare.]