Hypertension treatment logic
February 2, 2014 4:40 AM   Subscribe

I am a 52 year-old male with high systolic blood pressure (around 150/80-90). For a year I've been on 10 mg of Lisinopril (an ACE inhibitor) which didn't make much difference; my doctor thus raised the dose to 20 mg, which also isn't making much difference. The doctor is now recommending that I add another pill into the mix, making a "combination treatment" which I believe it standard. What I don't understand, and what nobody has been able to clearly explain to me, is the logic of continuing to take, every day, 20 mg of a pill that has been proven not make a difference. What's the thinking behind this, rather than simply trying out a one-pill solution that might make a difference?
posted by Holly to Health & Fitness (8 answers total) 1 user marked this as a favorite
I have no direct knowledge of these medications, but generally, some pills boost the effectiveness of other pills. That'd be my guess.

It could also be something along the lines of pill A does a pretty good job, usually. Pill B does a phenomenal job, but with consequences. Just a little bit of Pill B can boost the effectiveness of Pill A, keeping you out of the range of having to take a lot of Pill B with the bad consequences.

It could also be that Pill A needs to be cancelled slowly, and if B is effective, they'll take you off of A slowly.

It can get pretty complicated, and clinicians often follow best practice guidelines and may have read the journal articles, but it might be old news. Like, they read the articles 5 years ago (7000 articles ago) and don't remember exactly why this is best practice, but have the confidence that it is.

You're right to be curious - it is a totally legit question. you could print out this askme and bring it with you to your next appointment. Or ask a pharmacist! They're often happy to take a stab at questions like "what is my doctor thinking?"
posted by vitabellosi at 5:13 AM on February 2, 2014

Many chronic conditions require multiple medications to control. It is a normal part of starting out with drug management that you try one, then increase it, then add another if the first one is not sufficient even at maximum dosage.

If you took drug #2 by itself, it probably wouldn't be very effective on its own either. The main reason is that the drugs work synergistically - they work on different pathways to reduce blood pressure. When they are taken together each exerts a partial effect on a different pathway, adding up to a larger reduction than with one drug alone.

Many patients require 3 drugs, so 2 isn't at all unusual. Once your drugs & dosages are worked out, your doctor might prescribe combined medications - where you get two drugs in one pill.

Everyone gets an ACE inhibitor (the drug you named) if they have high blood pressure, unless it causes side effects or there are special reasons they can't take it, due to the large amount of evidence supporting their use from clinical trials.

Another reason to use an ACE inhibitor is that it has beneficial side effects, such as protecting the kidneys in some people, so your doctor might have this in mind.

If you don't like the idea of taking multiple drugs, the lifestyle interventions suggested by your doctor will in time reduce the doses and sometimes the number of drugs you need to take.
posted by JeanDupont at 5:34 AM on February 2, 2014 [1 favorite]

Great answers -- nicely complementary, too. "Synergistically" could be the explanation. Many thanks to both.
posted by Holly at 6:22 AM on February 2, 2014

You don't mention if you have heart disease or diabetes or heart failure. An ACE is often given to people with hypertension and one or both of those other issues. I do not know an exact, detailed explanation for that (I just type reports for cardiologists all day and that is what I see), but I gather the ACE will lower your risk.

When the next pill is added, watch yourself because you might suddenly have a very low blood pressure and need to have the lisinopril titrated downward to prevent orthostatic hypotension (stand up, blood pressure drops, get dizzy, fall down) or just hypotension due to overmedication.

Sometimes the lisinopril is actually doing something for you but you don't know that until it is gone or until you take another pill.

If you don't believe the doctor will give you an informative/sufficient answer, ask your pharmacist as well. They can explain a bit about how the drugs work with different risk factors and they usually have a bit more time/patience to do it.
posted by AllieTessKipp at 9:37 AM on February 2, 2014

The book Hypertension and You: Old Drugs, New Drugs, and the Right Drugs for Your High Blood Pressure , by Samuel J. Mann, goes into this and other questions on hypertension drugs in great detail. I strongly recommend it.
posted by Ery at 9:50 AM on February 2, 2014 [1 favorite]

Thank you. All this is really valuable.
posted by Holly at 11:25 AM on February 2, 2014

There are quite a few drugs used to lower blood pressure. American Heart Association does a real good job of explaining the different classes of drugs and how the drug works.

For example, the ACE inhibitors tries to prevent the enzyme from being formed and the Receptor Blocker blocks any of the enzyme that is formed from working with the cells.

Angiotensin-converting enzyme (ACE) inhibitors help relax blood vessels. ACE inhibitors prevent an enzyme in your body from producing angiotensin II, a substance in your body that affects your cardiovascular system by narrowing your blood vessels and releasing hormones that can raise your blood pressure. This narrowing can cause high blood pressure and force your heart to work harder.

Angiotensin II recptor blockers - These drugs block the effects of angiotensin, a chemical that causes the arteries to become narrow. Angiotensin needs a receptor- like a chemical "slot" to fit into or bind with- in order to constrict the blood vessel. ARBs block the receptors so the angiotensin fails to constrict the blood vessel. This means blood vessels stay open and blood pressure is reduced.
posted by JujuB at 2:21 PM on February 2, 2014

I was started on hydroclorothiazide for my high blood pressure. Didn't do much of anything. Then they added lisonopril to the mix. It helped some, but not enough. So they added metroprolol (sp?) That combo did the trick.

They'll try one first to see what works - everyone is different, and what works on one may not work on another. If they put you on hydroclorothiazide, there's a combo pill with that and lisonopril, at least in common doses.
posted by azpenguin at 10:21 PM on February 2, 2014

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