# Blood Pressure tx.: Basic EMT & Review for EMT/P



## Ridryder911 (Jul 7, 2005)

I was reviewing for Boards again & was discussing with my partner of blood pressure tx. regime. As a Basic EMT she had no insight of med.'s etc.. so I though I would start posting some tx. on EMS forums & plans on different treatments for blood pressure & how they work.... 

Inhibitors 
benazepril - Lotensin by Novartis 
captopril - Capoten by Bristol-Myers Squibb 
enalapril - Vasotec by Merck 
fosinopril - Monopril by Bristol-Myers Squibb 
imidapril - Not approved for human use in the USA - approved in Japan 
lisinopril - Prinivil by Merck or Zestril by Astra-Zeneca 
moexipril - Univasc by Schwarz Pharma 
quinapril - Accupril by Pfizer 
perindopril erbumine - Aceon by Rhone-Polenc Rorer 
ramipril - Altace by Hoechst Marion Roussel, King Pharmaceuticals 
trandolapril - Mavik by Knoll Pharmaceutical (BASF) 


ARBS - Angiotension II Receptor Blockers 
candesartan cilexetil - Atacand by Astra Merck 
eprosartan - Teveten 
irbesartan - Avapro by Sanofi 
losartan - Cozaar by Merck 
olmesartan medoxomil - Benicar by Sankyo Pharma 
telmisartan - Micardis 
valsartan - Diovan by Novartis 

Angiotensin II - The Problem 
We are talking about the chemical messengers in the body called neurohormones. For those patients with heart failure (CHF), the neurohormone called angiotensin II is not a good thing. 
Angiotensin II helps controls the cardiovascular system. It causes blood vessels to shrink (vasoconstriction), which raises blood pressure. Angiotensin II also causes the body to release a hormone aldosterone - a substance that causes our kidneys to retain sodium and fluid, causing edema. 
Angiotensin II also causes the body to release a substance called vasopressin or ADH, which causes the patient to retain fluid even more. Angiotensin II is a real problem for CHFers. 

ACE Inhibitors - Why They Work 
We all have angiotensin one in our systems. Angiotensin one is converted into angiotensin II by an enzyme in your body called ACE (Angiotensin Converting Enzyme). No not the store ACE....ACE is what we block with ACE inhibitors - blocking it prevents angiotensin I from converting into angiotensin II. 
Reducing angiotensin II lets our blood vessels relax and expand, or dilate. This lowers blood pressure, which makes the heart's job a lot easier. Thus decrease work load on the pre-load or blood amount to pump. 
Think of it this way: If you pump the same amount of water at the same speed through a little pipe as through a big pipe, there's higher pressure in the small one. The fluid shoots out of the small pipe, but calmly flows out of the big one, even though they are both moving the same amount of water. The pump pushing the water through that skinny pipe has to work a lot harder than the pump glushing it through the big pipe. The fancy word is peripheral resistance. 
The same principle applies to our blood vessels. If our arteries relax, they get bigger (vasodilation) and the pump has an easier job - less pressure. That's called reducing "afterload." ACE inhibitors do this for us. "Super" ACE inhibitors called vasopeptidase inhibitors were also tested for CHF but carry higher risk for side effects. 
ACE also helps control the amount of blood in your body - your blood "volume." Blocking ACE reduces the overall amount of blood in your body. This means the tired old heart has less blood to pump, which makes its job easier. ACE inhibitors increase the level of potassium in your blood, so they partly offset potassium loss caused by diuretics like Lasix and Demadex. 
Finally, ACE inhibitors help CHF patients live longer and feel better. The articles below show that ACE inhibitors reduce the risk of death by 20% to 40%. The other two types of drugs that do this are beta-blockers and Aldactone (spironolactone). ACE inhibitors slow heart remodeling, preventing our hearts from getting even weaker over time. 
It can take several months for the full effect of ACE inhibitors to show up, and improve the quality of life. CHFers should be on them if possible. It is AHA official heart failure treatment guidelines. 
Unfortunately, many doctors don't offer ACE inhibitors if the patient has any kidney problems or if our blood pressure is low. This is unwise Monopril (fosinopril) is processed by the liver as well as the kidneys, so CHFers with kidney problems can usually take it okay. People with low blood pressure, surprisingly enough, often tolerate ACE inhibitors quite well (although not always). 


ARBs 
Angiotensin II Receptor Blockers 
Angiotensin II is also made at other places in the body. So ACE inhibitors can't completely stop angiotensin II from affecting CHF patients. After starting an ACE inhibitor, there is a period where angiotensin II is almost completely stopped. Over time, angiotensin II level rises again, from these other places in the body. 
Since ACE inhibitors can't do it all, it seems like a good idea to block the stuff at other places too. ARBs block angiotensin II receptors on cell walls. If angiotensin II can't connect to cell receptors, it can't affect patients. The most important receptor is called the AT-1 receptor (there is also an AT-2 receptor). ARBs do help CHF. The question is: Do ARBs help CHFers already taking an ACE inhibitor? Studies are still being conducted 

A study called RESOLVD; compared an ARB alone to using an ACE inhibitor alone to using both an ACE inhibitor and an ARB. Using both worked better to improve heart enlargement (cardiomyopathy)and ejection fraction function (amount of blood squirted out in one stroke) EJF. 
The ValHeft trial added an ARB to standard CHF therapy. Complications and mortality improved most in CHFers taking the ARB with either an ACE inhibitor or a beta-blocker, but not in those taking all 3 drugs. Why taking all 3 drugs gave worse results is unknown. 
ARBs do have some excellent uses we are sure about. In patients who develop a bad cough from using an ACE inhibitor, an ARB can often be used without the cough. In patients who don't tolerate an ACE inhibitor for some other reason, an ARB will often do the job. 
Note - Telmisartan can significantly raise blood digoxin levels, so be cautious in patients you see on this med. & consider Dig Tox. 

In Conclusion,... 
Even if the patient begins to have a normal cardiac output & normal heart function most physicians will keep the patient on an ACE inhibitor for life, and that's smart. It may stop or prevent them from getting CHF again down the road - which usually happens. 
ACE inhibitor use may reduce your zinc level so you might want to take a zinc supplement. Their sense of taste could possibly go goofy on you after starting an starting ACE inhibitor too - especially on captopril. 
So patients may not eat as well or complain of decreased appetite. Which could complicate things for diabetic patients. 

Thought this would help understand some of your patients blood pressure medication(s). Maybe a review for some of the advanced level. 

Be safe, 
Ridryder 911


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