Hypertension

By Ankur Rathore

What is Hypertension (HTN)?

High blood Pressure (BP) Systolic pressure > 140 mm Hg Diastolic pressure > 90 mm Hg

Classification of Hypertension Primary Secondary

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Pathophysiology of High BP

Blood pressure – is the force of blood exerted on arteries as it flows through them Classification of BP – Systolic – Diastolic

(mm Hg) (mm Hg) Normal <120 <80 Prehypertension 120-139 80-89 Stage 1 Hypertension 140-159 90-99 Stage 2 Hypertension >160 >100

Blood Pressure Control Mechanism

Blood Pressure

Depends on:-Cardiac Output

-Contractility-Fluid Volume

-Peripheral vascular resistance

Is affected by:-Nervous system-Kidney function-Hormonal changes-Capillary fluid shift

Causes of Hypertension

Aging Smoking Obesity High sodium (salt) diet High cholesterol Lack of exercise Drinking Being insulin resistant

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www.dailygalaxy.com

Risk Factors of HTN

Smoking Age

Women older than 65 years of age Men older than 55 years of age

Obesity Diabetes Lack of Physical activity Chronic alcohol consumption Family history of cardiovascular disease Sex – men and postmenopausal women African American 2x more likely than Whites

Facts About Hypertension

According to American Society of HTN 50 millions of Americans are affected More than 90% of cases have no cause Children who’s parents have HTN will more likely

be affected HTN is called a “SILENT KILER” due to having no

warning signs or symptoms but increases one’s risk of cardiovascular collapse

Due to not being aware of having HTN, only ¼ of people are being treated

What are the Symptoms?

Prehypertension and Stage 1 HTN Usually none

Stage 2 HTN If occurs rapidly – symptoms of

Hypertensive Crisis Headache (pulsating behind eyes more in the

AM) Visual disturbances Nausea & vomiting

How is HTN Diagnosed?

Usually by routine doctor’s visit One high BP reading does not mean you

have HTN Repeated BP reading will be done at

different positions Complete physical, medical and family

history will be performed Risk factors identified

Treatment of HTN

There are following steps in treating HTN

1. Lifestyle modification

2. First line treatment

3. Second line treatment

4. Third line treatment

Lifestyle Modification

Weight reduction Reduction of sodium intake Decrease of alcohol intake Smoking cessation Increase in physical activity If inadequate, continue to first line

treatment

First Line Treatment

Continue with lifestyle modification Initial drug selection:

Diuretic Beta-blocker If inadequate, continue to second line

treatment

Second Line Treatment

Adding drugs from the folloving categories Angiotensine Converting Enzyme (ACE)

Inhibitor Calcium Channel Blocker Angiotensine II Receptor Blocker (ARB) α- blocker, α- and β-blocker If inadequate, continue to third line

treatment

Third Line Treatment

Increase drug dose, or Substitute another drug, or Add a second drug from another class If inadequate, may need to do further

studies Serious organ damage may be present

Possible Outcomes of Delayed Treatment of HTN

Stroke Myocardial infarction Congestive heart failure Renal failure

www.nlm.nih.gov

Hypertension Treatment

Drugs Used to Treat HTN

Diuretics Furosemide (Lasix); Hydrochlorothizide

(HydroDIURIL) Beta blockers

Atenolol (Tenormin); Propranolol (Inderal) ACE inhibitors

Captopril (Capoten); Enalapril (Vasotec) ARB’s

Irbesartan (Avapro); Losartan (Cozaar) Calcium channel blockers

Amlodipine (Norvasc); Diltiazem (Cardizem)

Site Of Action of Antihypertensive Drugs

Action of Beta-Blockers Block vasoconstriction Decrease heart rate Decrease cardiac muscle

contraction Tend to increase blood flow to

the kidneys -> leading to a decrease in the release of renin

What Are Beta-Blockers?

Beta blockers are Beta-adrenergic receptor blockers – they block action of Adrenalin and Noradrenaline (SNS stimulants), which are involved in “Fight-or-flight’ response

There are two types of Beta receptors β1 – found mostly in the heart Β2 – found mostly in the lungs

Classification of Beta Blockers

β1 receptors blockers Atenolol (Tenormin) Betaxolol (Kerlone) Bisoprolol (Zabeta) Metoprolol (Lopressor, Toprol-XL)

β1, β2 receptor blockers Nadolol (Corgard) Propranolol (Inderal, Inderal LA)

β1, β2, α receptor blockers Labetolol (Normodyne, Trandate)

Beta Blockers

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Commonalities:

-One chiral center-Aromatic ring-Side alkyl chain-Secondary hydroxyl group-Amine

Discovery of Beta Blockers

Started in 1950’s when “Heart disease had become a serious epidemic”

By Sir James Black, an English physician and a basic scientist who started research in Glasgow Veterinary School laboratory

His goal was to find a drug that would decrease the oxygen demand in the heart

He developed the first Beta-blocker – Propranolol (Inderal) in 1964

It successfully blocked the heart’s adrenaline-responsive beta-receptors

Hence the name “Beta-Blockers” He was awarded the Nobel Prize in 1988 for this and

other discoveries

Beta Blockers – Side Effects Fatigue Orthostatic hypotension Weakness Blurred vision Stuffy nose Impotence Rash CHF Bradycardia Pulmonary edema

Treatment of Side Effects

Changing position slowly Sit at the edge of bed or chair for a few

minutes before standing up Drink adequate amount of fluids Contact physician in more serious case

to adjust the dose or change the medication

How Much the Drug Cost?

Drug Name Dosage of PO drug

Frequency of Use

Monthly

Cost of Generic

Monthly Cost of Brand

Atenolol (Tenormin) 25mg

50mg

2x/day $10

$10

$47

$47

Betaxolol (Kerlone) 10mg 1x/day $30 $41

Bisoprolol (Zabeta) 10mg 1x/day $38 $55

Labetolol (Normodyne) 100mg 2x/day $26 $38

Metoprolol tartrate (Lopressor)

25mg

50mg

1x/day

1x/day

$9

$9

$35

$35

Nadolol (Korgard) 20mg 1x/day $18 $59

Propranolol (Inderal) 20mg

40mg

2x/day

2x/day

$13

$15

$44

$56

Propranolol

Nursing2007 Drug Handbook

Initial Dose in treating HTN- 80mg PO 2x/day- 80mg extended release form 1x/day

Increase at 3-7 day intervals to max daily dose of 640mg

Maintanance dose -120-240mg daily-120-160mg extended release form

Propranolol Metabolism

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Part of my future research

Further Research

Development of propranolol from the lead compound

Pharmacokinetics and pharmacodynamics of propranolol in our body

Interview with heart specialists at Atlanta Medical Center about current treatment of HTN

Interview with my family members and clients with HTN – how is their life affected by this condition

QUESTIONS?

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References

Beta Blockers – common dosage guidelines (2008). The clinician’s Ultimate Reference Retrieved March 15, 2008 from http://www.globalrph.com/beta.htm

Karch, A. (2006). Focus on Nursing Pharmacology. (3rd. Ed.). Philadelphia: Lippincott Williams &Wilkins

Pharmacokinetics and Pharmacodynamics Mehvar, R.; Brocks, D. R. (2001). Stereospecific of Beta-Adrenergic Blockers in Humans. J Pharm Pharmaceut Sci 4(2), 185-200. Retrieved march 15, 2008 from http://images.google.com/imgres?imgurl=http://www.ualberta.ca/~csps/JPPS4(2)/R.Mehvar/Fig2.gif&imgrefurl=http://www.ualberta.ca/~csps/JPPS4(2)/R.Mehvar/betablockers.htm&h=629&w=490&sz=9&hl=en&start=7&tbnid=-br7jKXMxHZijM:&tbnh=137&tbnw=107&prev=/images%3Fq%3Dpropranolol%26gbv%3D2%26hl%3Den%26sa%3DG

Popple, I. (2004, October 14). How Beta-Blockers came To Be. McGill Reporter, 37(3), 2004-2005. Retrieved March 15, 2008 from http://www.mcgill.ca/reporter/37/03/black/

Propranolol tablets Retrieved March 15, 2008 from psyweb.com Treating the High Blood Pressure and Heart Disease: Beta-blockers. (2008).

Consumer Reports:Best Buy Drugs Retrieved March 13, 2008 from http://www.consumerreports.org/health/resources/pdf/best-buy-drugs/2pager_BetaBlockers.pdf