AntihypertensiveLori Kenavan

NUR- 304 PharmacologyProf. Lynn McNall

Fall 2012ESC

Learning objectives

• Describe the role of Antihypertensives and its actions.

• Discuss whom receives Antihypertensive medications.

• List categories and subcategories of Antihypertensive Drugs.

Classification

• Drugs used in the management of primary HTN belong to several different groups:

• Angiotensin-converting enzyme ACE inhibitors• Angiotension II receptor blockers ARBS• Calcium channel blockers • Diuretics• Vasodilators

These drugs act to decrease blood pressure by decreasing cardiac output or peripheral vascular resistance.

Introduction

Hypertension

Systolic BloodPressure (SBP)

Diastolic BloodPressure (DBP)

>140 mmHg >90 mmHg

HTN

Types ofHypertension

Essential Secondary

A disorder of unknown origin affecting theBlood Pressure regulating mechanisms

Secondary to other disease processes

Environmental Factors

Stress Na+ Intake Obesity Smoking

WHY TREAT HTN?

• Treatment is mandatory when symptomatic: • Damage to the vascular epithelium, paving the

path for atherosclerosis (CVA) or nephropathy due to high intra-glomerular pressure.

• Increased load on heart due to high BP. Can cause CHF.

• HTN, even asymptomatic needs interventions.

Antihypertensive Drugs and Its mechanism of Action

• Diuretics: • Thiazides: Hydrochlorothiazide, chlorthalidone• High ceiling: Furosemide• K+ sparing: Spironolactone, triamterene and amiloride

MOA: Acts on Kidneys to increase excretion of Na and H2O- decrease in blood volume = decreased BP.

Angiotensin- converting Enzyme (ACE) inhibitors:

• Captopril, lisinopril, enalapril, ramipril and fosinopril

M0A: Inhibit synthesis of Angiotensin II- decrease in peripheral resistance and blood volume.

Angiotensin (AT1) blockers:

• Losartan, candesartan, valsartan and telmisartan

Anti-HTN M.O.A• MOA: Blocks binding of Angiotensin II to its receptors.

• Centrally acting:

-Clonidine, methyldopa• MOA: Act on central receptors to decrease sympathetic

outflow- fall in BP • B-adrenergic blockers:

Non-selective: Propranolol (nadolol, timolol, pindolol, labetolol)

Cardioselective: Metoprolol (atenolol, esmolol, betaxolol)• MOA: Bind to beta adrenergic receptors and blocks the

activity

B and a- adrenic blockers:

Labetolol and carvedilol

a-adrenergic blockers:

Prazosin, terazosin, doxazosin, phenoxybenzamine and phentolmine.

Anti-htn m.o.a

• MOA: Blocking of alpha adrenergic receptors in smooth muscles- vasodilation. • Calcium Channel Blockers (CCB):

• Verapamil, diltiazem, nifedipine, felodipine, amlodipine, nimodipine etc.

• MOA: Blocks influx of Ca++ in smooth muscle cells- relaxation of SMCs = decrease BP• K+ Chanel activators:

• Diazoxide, minoxidil, pinacidil and nicorandil

Anti-Htn M.O.a

• MOA: Leaking of K+ due to opening- hyper polarization of SMCs = relaxation of SMCs• Vasodilators:

• Arteriolar- Hydralazine (also CCB and K+ channel activators)

• Arterio- venular: Sodium Nitroprusside.

antihypertensives

Indications for use

1. Significant hypertension• Infants >80 mm Hg DBP• Children >86 mm Hg DBP• Adolescents >90 mm Hg DBP

2. Evidence of target organ damage

3. Symptoms or signs related to elevated blood pressure

Allergic and adverse effects

• Common side effects: • slight dizziness, fatigue, cough and headache.

• Serious side effects: • insomnia, decreased sex drive, shortness of breath

and depressed mood. Contact physician and stop medication.

• Severe side effects: • chest pain, difficulty breathing, fainting, irregular

heartbeat and rash. Swelling of the face, lips, tongue or extremities may be the sign of an allergic reaction to the medication. For these symptoms, treatment should not be delayed and seek medical help.

Choice of drug

• Choice of drugs in treating hypertension:

• Patients with diabetes – ACEI

• Patients with congestive heart failure or left ventricular dysfunction- ACEI

• Patients with angina pectoris – a beta adrenoceptor blocker

• Patients with migraine - a beta adrenoceptor blocker

• Patients with myocardial infarction – a beta adrenoceptor blocker, ACEI

• Patients with hyperlipidemia – ACEIs, -adrenoceptor antagonists, and

Ca channel blockers

• Black patients – diuretics and Ca channel blockers are more effective

Older patients with isolated systolic hypertension – diuretics,

dihydropyridine Ca channel blockers.

Some Herbal Solutions

• Garlic - Garlic is beneficial for those with hypertension. By thinning the blood garlic can lower blood pressure by 5 to 10 percent. It can also lower cholesterol and discourage clot formation. Unfortunately, garlic has a reputation for being an "anti-social" food, but with all of the health benefits that garlic provides, bad breath should be the least of your worries.

• Fish oil – Fish oil may have a modest effect on high blood pressure. Although fish oil supplements often contain both DHA (docohexaenoic acid) and EPA (eicosapentaenoice acid), there is some evidence that DHA is the ingredient that lowers high blood pressure.

• Folic acid - Folate is a B vitamin necessary for formation of red blood cells. It may help to lower high blood pressure in some people, possibly by reducing elevated homocysteine levels. One small study of 24 cigarette smokers found that four weeks of folic acid supplementation significantly lowered blood pressure.

Herbal cont.

• There are many more such as: Vit C, Celery, Cayenne, Ayurveda, Black Cumin Seeds, Rauwolfia serpentina, Ca Mg K, high fiber foods, seaweeds.

• Avoid natural licorice products.

Yoga and meditation

• Yoga can fight off the causes of the abnormal blood pressure. It helps both type of blood pressure and stabilizes blood pressure.

• Some yoga poses for high blood pressure include- Easy Pose (Sukhasana), Shoulder Stretches, Stand spread leg forward fold, Cat Pose (Bidalasana) and many more.

• If you do transcendental meditation, it reduces your blood pressure as it decreases the constriction of the blood vessels.

• By doing meditation daily, you not only keep your blood pressure under control but also avoid the complications that you might develop because of hypertension. So, meditation is one of the best ways to prevent and treat your abnormal BP!

Dietary Solutions

• A low sodium low calorie diet.

• Hydration is key. Adequate fluid intake is necessary.

• Limit alcohol use.

• Watch intake of Grapefruit: can potentiate antihypertensives- Calcium channel blockers.

O.T.C

• Many over-the-counter painkillers can push blood pressure higher.

• Some types of nonsteroidal anti-inflammatory drugs (NSAIDs) can be risky.

• ibuprofen., naproxen sodium, and ketoprofen, the active ingredients in meds like Advil and Aleve.

• Some of these NSAIDs reduce the blood flow to the kidneys. The kidneys -- which filter your blood -- work more slowly, and so fluid builds up in your body. The increased fluid drives up your blood pressure.

• Other options: Ice packs, heat, physical activity, relaxation, acupuncture.

Nursing considerations:Diuretics

• Diuretics can increase serum glucose and cholesterol levels, monitor for hyperglycemia and hypercholesterolemia.

• Teach patients to take diuretics in the morning to avoid nocturnal diuresis and urination.

• Caution patients to stand up slowly to minimize the risk of dizziness from orthostatic hypotension.

• Monitor for signs of hypo kalemia, such as muscle weakness and changes in mental status, including confusion and irritability.

NC: Diuretics con’t.

• Patients taking a potassium-sparing diuretic are at risk for hyperkalemia. The risk is especially high in patients also taking an angiotensin-converting enzyme (ACE) inhibitor.

• Weigh patients daily at the same time using the same scale. Report a significant weight gain, 3 pounds in 3 days.

• Remind your patient that even if he feels fine, he should keep appointments with the healthcare provider because renal function must be monitored.

Nursing ConsiderationsBeta-Blockers

• Teach patients that they shouldn’t suddenly stop therapy because of the risk of rebound tachycardia and hypertension.

• Beta blockers can cause transient increases in serum lipid and glucose levels.

• Monitor for symptoms of hypoglycemia in patients with diabetes who use insulin.

• Some older beta blockers such as propranolol can cause broncho constriction and asthma symptoms.

• Check for common adverse effects of beta blockers, such as dizziness, slowing of the pulse, fatigue, and hypotension.

Nursing Considerationsalpha-blockers

• Warn patients about the risk of orthostatic hypotension, which can cause falls.

• Teach patients to take their first dose at bedtime and to move slowly from a sitting to a standing position.

Nursing Considerationscalcium channel blockers

• Tell patients to report dizziness and symptoms of an irregular heart rate.

• Teach your patients to avoid grapefruit juice because it inhibits the hepatic metabolism of calcium channel blockers and may lead to increased blood drug levels and increased pharmacologic effects.

• All calcium channel blockers should be used cautiously in patients with heart failure.

Nursing ConsiderationsACE-Inhibitors and angiotensions

• Assess patient for hyperkalemia.

• Rare adverse effects include: agranulocytosis, proteinuria, glomerulonephritis, acute kidney failure, and angioedema.

• Assess for angioedema, which can lead to airway swelling and requires emergent treatment.

• A history of angioedema contraindicates the use of ACE inhibitors.

Nursing Considerations• Tell patients not to stop taking these drugs on their own

because an abrupt withdrawal can result in rebound hypertension.

• Teach to take own blood pressure daily and record it, bringing the record to scheduled clinic visits.

• Teach name, dose, action, and side effects of antihypertensive medication.

•  Instruct patient to develop a daily exercise routine.

•  Discuss strategies for maintaining a healthy weight.

• Refer for a dietary consultation for further teaching about the DASH diet.

• Discuss stress-reducing techniques, helping identify possible choices.

Video’s

• http://youtu.be/4jRy-YlZONA

(Understanding HTN)

• http://youtu.be/9zTFVmUK1gk

(Antihypertensive Meds)

• http://youtu.be/wqJA2FfTPwk

(Guide to lowering HTN)

PLEASE CLICK ON LINK’S

FOR SHORT VIDEOS

Questions

• 1. When giving antihypertensive drugs, the nurse must consider giving the first dose at bedtime for which of the fallowing classes of drugs?

A. a-Blockers such as prazosin (Minipress)

B. Diuretics such as furosemide (Lasix)

C. ACE inhibitors such as captopril (Capoten)

D. Vasodilators such as hydralazine (Apresoline)

Questions

• 2. A 56 yr. old man started anti-hypertensive drug therapy 3 months earlier and is in the office for a follow- up visit. While the nurse is taking his blood pressure, he informs the nurse that he has had some problems with sexual intercourse. Which of the following would be the most appropriate response by the nurse?

A. “Not to worry. Tolerance will develop”

B. “The physician can work with you on changing the dose and/or drugs”

C. “Sexual dysfunction happens with this therapy, and you must learn to accept it.”

D. “This is an unusual occurance, but it is important to stay on your medications.”

Questions

• 3. Which of the following adverse effects is most concern for the older adult patient taking antihypertensive drugs?

A. Dry mouth

B. Hypotension

C. Restlessness

D. Constipation

References

Abrams, A.C., Pennington, S.S., & Lammon, C.B. (2009). Clinical Drug Therapy; Rationales for Nursing Practice. (9th ed). Philadelphia, PA: Wolters Kluwer. Lippincott Williams & Wilkins.

Frohlich E.D., Apstein C., Chobanian A.V., et al. (1992) The heart in hypertension. New Engl J Med 327:998–1008.

Ganau A., Devereux R.B., Roman M.J., et al. (1992). Patterns of left ventricular hypertrophy and geometric

remodelling in essential hypertension. J Am Coll Cardiol 19:1550–1558.

Koffland M.J.M., van der Lee C., ten Cate F.J., Roelandt J.R.T.C. (1998). Hypertrophic cardiomyopathy: update and new perspectives. Cardiologie 5:511–524.

References

Pegram B.L., Ishise S., Frohlich E.D. (1982). Effect of methyldopa, clonidine and hydralazine on cardiac mass and

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Pluim B.M., Vliegen H.W., van der Laarse A., van der Wall E.E. (1998). Pathological left ventricular hypertrophy. Cardiologie 5:574–582.

Savage D.D., Garrison R.J., Kannel W.B., et al. (1987). The spectrum of left ventricular hypertrophy in a general population sample: the Framingham study. Circulation 75(suppl.I):I26–I33.

Spirito P., Pelliccia A., Proschan M.A., et al. (1994). Morphology of the ‘athlete's heart’ assessed by echocardiography in 947 elite athletes representing 27 sports. Am J Cardiol 74:802–806.