Lines of Therapy – Drugs in Hypertension

00:01 Let's move on to special considerations in blood pressure management.

00:05 And I'm going to talk to you about mixing drugs now.

00:09 Okay, let's start out with taking a look at the different types of medications we use for hypertension control.

00:14 When you look at most guidelines for most countries all over the world, the first line agent is one of a choice of four different drug groups.

00:26 It doesn't matter which of these four you choose, in the absence of other diseases.

00:30 You could choose one of the ACE inhibitors, you could choose one of the ARBs, you could have choose chosen one of the calcium channel blockers, or you could choose a thiazide diuretic.

00:40 Any one of these four is correct.

00:43 Now, the second-line agents could include other types of diuretics, including the loop diuretics, like furosemide.

00:50 Or you could use the mineralocorticoid agents such as spironolactone or you could use a beta-blocker.

00:58 So those are second-line agents.

01:00 And then the other agents that we have talked about in other lectures would be third-line agents.

01:05 So to be clear, these are special drug mixtures or special drug choices in certain types of diseases.

01:12 This first slide refers to those patients who have high blood pressure in the absence of other diseases.

01:20 And this should fall in line with most countries guidelines on hypertension management.

01:26 Let's move on to other diseases.

01:29 Current guidelines, wherever you are in the world do not choose a first-line agent.

01:35 They determine a first-line set of choices based on the disease state.

01:41 So let's take diabetes, for example.

01:44 In general, diabetics, we like to use ACEs or a ARBs as a first-line agent, and then go on to a calcium channel blocker, and then to a diuretic, and then to spironolactone, and then to a beta-blocker.

01:57 Beta-blockers we try to avoid in diabetes, because it can mask the symptoms of hypoglycemia.

02:03 The reason why ACEs and ARBs are first-line therapy choices is because they also have vascular protection effects in the eye, in the brain, in the kidney, and we believe also in the peripheral vasculature.

02:18 That's why they are first-line in this class.

02:21 Proteinuria.

02:24 ACEs or ARBs? The next class of drugs that we would like to use in this disease state are the non-dihydropyridine calcium channel blockers.

02:33 I won't get into the details or the argument as to, whether or not adding it to an ARB or an ACE inhibitor is better.

02:40 There are several medications that can be used to treat hypertension in the setting of acute heart failure.

02:45 We often start with a combination therapy agent.

02:47 Either an ARB or ACE inhibitor with a diuretic.

02:51 Next, we would reach for direct vasodilators, such as, hydralazine or nitrates.

02:56 Another option would be spironolactone, which is, particularly helpful in treating hypertension in the setting of heart failure.

03:03 Use this with caution though, as combining an ACE inhibitor with spironolactone, can cause high potassium levels.

03:09 The next choice for controlling hypertension and heart failure are beta blockers, but use these with caution.

03:15 As adding a beta blocker during an acute exacerbation of heart failure, can further decrease the cardiac output.

03:21 It is safe to continue beta blockers during acute exacerbations, but do not initiate therapy with a beta blocker, until the patient has been stabilized.

03:30 Lastly, you can consider calcium channel blockers for controlling blood pressure.

03:34 But be sure to use dihydropyridine calcium channel blockers to avoid the negative inotropic effects of non-dihydropyridines.

03:42 In terms of the chronic heart failure patient, you can see how the order is changed a little bit.

03:46 ARB or ACE inhibitor, diuretic, spironolactone, beta blockers and then others such as neprilysin inhibitors.

03:55 In isolated systolic hypertension or “ISH”, our preferred agents are calcium channel blockers and thiazide diuretics.

04:03 These have been shown to be the most effective at reducing blood pressure.

04:07 The next best choice is to reach for an ARB. or ACE inhibitor.

04:10 After exhausting these options, consider other medications such as, beta blockers.

04:16 In terms of post-MI patients, it's absolutely essential that we get these people on beta blockers.

04:21 We're not using the beta blocker for hypertension, but I put this list here to reiterate the importance of using a beta blocker post-MI.

04:30 After that we'll use either an ACE or an ARB.

04:34 Now, on your exam both ACE’s and ARB’s are a correct answer.

04:39 In a cardiologist's office the correct answer is ACE inhibitor.

04:44 That's because ACE inhibitors have a lot of evidence to support its use.

04:48 The ARB’s also have a lot of evidence to support their use, but they're later drugs and could only be compared against ACE inhibitors and they were never shown to be truly superior in class 1 trials.

05:02 There is another trial that suggested that ARB’s are better, but it was an observational study, it looked at a large group of patients in the province of Ontario and Canada and it showed that the ARB’s did quite well in those patients, but still you'll often find clinically people are favoring ACE inhibitors.

05:21 On your exam we should treat them equally.

05:25 Pulmonary Edema is something we commonly see in both the intensive care unit and coronary care unit.

05:31 Oral diuretics will not be potent enough to achieve the rapid diuresis that is needed for these patients.

05:37 Give intravenous furosemide, starting with a 40-milligram dose, track the patient's intake and output closely to ensure an adequate response.

05:46 If not responding to the intravenous furosemide, patients can be given a dose of oral metolazone, 30 minutes before the next dose of furosemide.

05:54 This essentially primes the pump and allows for massive diuresis.

05:58 When using this combination be aware that there is a high risk of hypokalemia, so be sure to monitor this closely.

06:05 Despite the risk of electrolyte abnormalities, this is a very effective therapy for a person with fluoride heart failure that is not responding to furosemide alone.

06:15 Let's talk about the ascites special.

06:18 So sometimes you'll have patients who either have liver cancer or liver failure or abdominal ascites for some other reason.

06:26 Giving spironolactone 100 milligrams in combination with furosemide 40 milligrams is quite an effective combination medication drug regimen.

06:37 Keep that ratio the same so, for every 100 milligrams of spironolactone, you give 40 of furosemide, so, you can give 100/40, 200/80, 300/120, or 400/160.

06:51 400/160 is a mega dose, so, you really need to know what you're doing if you're going to use that dose.

06:57 But definitely it works quite well with patients who have ascites.

07:02 If you're wondering where the source of this is, is, if you look at a New England journal of medicine article on the treatment of ascites.

07:08 It's an old article but it's a good one, you can look at it and see how the mechanism actually works.