HYPERTENSION

BY: DR. MARWA SHAALANPHARM-D

HTN = BP > 140/90

Assos. With: premature death vascular disease of brain,

heart,kidneys

HYPERTENSION

Goal of treatment

Prolong useful life by preventing cardiovascular problems by reducing

BP < 140/90

Types of Hypertension Primary HTN: also known as

essential HTN. accounts for 95%

cases of HTN. no universally

established cause known.

Secondary HTN: less common

cause of HTN ( 5%).

secondary to other potentially rectifiable causes.

Blood Pressure Primary Factors

1. Cardiac output2. Peripheral resistance3. Blood Volume

Initial tx. of hypertension Lifestyle modification first No smoking Weight control Reduce alcohol intake Decrease stress Sodium control

Treatment of hypertension Lifestyle modification first Initial tx. drug- diuretic or B-

blocker Low dose first, increase dose if

necessary 2nd med. if needed Most respond with diuretic and one

other medication (stepped care)

Drugs to treat hypertension

5 primary classes1. Diuretics2. Calcium channel blockers3. Angiotesin converting enzyme

(ACE) inhibitors4. Autonomic nervous system agents5. Direct acting vasodilators

1- Diuretics Treats: mild to moderate HTN First drug of treatment of

hypertension. Also treats heart failure or kidney

disease Few adverse side effects Used with other anti-hypertensives

to enhance effectiveness

DiureticsAction

Reduce blood volume through urinary excretion of water and electrolytes

1. Electrolyte imbalances can occur (mainly hypokalemia)

2. Depends on type of diuretic

Diuretics

Most efficient: Loop or High-ceiling Reduce edema associated with CHF Increase Urine output even if blood flow

to kidney is diminished Hypokalemia KCL supplement given Lasix, Demadex, Bumex

Diuretics

Most widely prescribed: Thiazides Mild to moderate HTN-primarily Hydrodiuril – hydrochlorothiazide

(HCTZ) Hypokalemia Potassium supplement- KCL

Diuretics Potassium-sparing:prevent

hypokalemia Mild HTN Used in combination with other

diuretics No supplement taken Watch for hyperkalemia

Side effects Orthostatic hypotension Dry mouth,irritation Report: Electrolyte imbalance-

hypokalemia (potasium<3.5) Disorientation dehydration

Implications for use

Optimal time to admin.= AM Accurate intake and output Daily weights Monitor electrolyte imbalances

2-Calcium Channel Blockers

Emerged as major drug to treats HTN

Used for arrythmias also Alternative to B-blocker ( esp.in

Asthma patients)

Calcium Channel Blockers

Action:blocks ca+ access to muscle cells

contractility + conductivity of the ______________________ demand for oxygen PVR (relaxing arterioles)[peripheral

vascular resistance]

Calcium Channel Blockers Examples Verapamil Very

Procardia (nifedipine)-HTN Nice

Cardizem (diltiazem)-arrythmias Drugs

Calcium Channel Blockers SIDE EFFECTS

BP Bradycardia May precipitate A-V block Headache Abdominal discomfort Peripheral edema

3-Angiotensin-Converting Enzyme Inhibitors “ACE” inhibitors Mainstay of oral vasodilator

therapy Major breakthrough in treatment of

HTN More effective when used with

diuretics

ACE INHIBITORS

Angiotensin Converting Enzyme (ends in PRIL)

captopril enalapril benzapril(Capoten) (Vasotec) (Lotensin)

RENIN-ANGIOTENSIN-ALDOSTERONE AXN. BP

excrete renin

formation of angiotensin I angiotensin II = potent vasodilator Aldosterone release Na and H2O

ACE INHIBITORS ACTION

peripheral vascular resistanse without

Ø cardiac outputØ cardiac rate Ø cardiac contractility

Advantages Infrequent orthostatic hypotension Lack of aggravation of pulmonary

disease. Lack of aggravation with Diabetes

Mellitus Increase renal blood flow

Side effects

Headache Orthostatic hypotension-infrequent Cough GI distress

Drug interactions Diuretics Alcohol Beta-blockers

All the above enhance the effects

4-Adrenergic ReceptorsReview of ANS

Sympathetic Nervous System Alpha 1 = vasoconstriction Alpha 2 = feedback/vasodilation Beta 1 = increases heart rate Beta 2 = bronchodilation

A-Beta Adrenergic Blocking Agents Known as Beta-blockers Anti-adrenergic: Inhibit cardiac

response to sympathetic nerve stimulation by blocking Beta receptors

Decreases heart rate and Cardiac output

Decreases blood pressure

Beta Adrenergic Blocking Agents

Examples – “olol” names

Beta 1: Atenolol Beta 1 and 2: Propranolol

Implications

Can not be abruptly discontinued

Check baseline b.p. Check patients of resp. condition-

aggravates broncho-constriction

Side effects

Bradycardia Bronchospasm, wheezing Diabetic: hypoglycemia Heart failure:

edema,dyspnea,rhales

Interactions Antihypertensives- additive effect Anti-adrenergic effects.

Enzyme inducing agents-enhance metabolism

Indomethacin and salicylates:< controll

B-Alpha-1 adrenergic blockers

Alternative if B-blockers and diuretics do not work

Also used to treat mild to mod. urinary obstructive disease. (BPH)

Alpha-1 Adrenergic Blocking Agents

Action: Block postsynaptic alpha-1

adrenergic receptors to produce arteriolar and venous vasodilation

Reduces peripheral-vascular resistance

Side effects Drowsiness Headache Dizziness,tachycardia,fainting Weakness,lethargy

Interactions: other antihypertensives (enhance effects)

Clinical Implications Side effects most prevalent with

first dose Warn patient that this is normal Instruct pt. to lie down if

dizzy ,weak ….,etc.

Examples of Apha-1 blockers

Cardura (doxazosin) Minipress (prazosin)

C-Centrally Acting Alpha-2 Agonists

Stimulate Alpha-2 receptors in brainstem

Decreases HR, SBP and DBP More frequent side effects –

drowsiness, dry mouth, dizziness Never suddenly Discontinued =

rebound HTN Clonidine [ Catapress] Methyldopa [Aldomet]

5-Direct Acting Vasodilators Action: direct arteriolar smooth

muscle relaxation, decreasing PVR Uses: HTN, renal disease, toxemia

of pregnancy Ex: Apresoline, Minoxedil SE: tachycardia, orthostatic

hypotension , dizziness, palpitations, nausea, nasal congestion

Patient Teaching forAntihypertensive drugs Take medication as prescribed Never discontinue without approval of

healthcare provider Incorporate lifestyle changes, even if

medication brings BP within normal Limits

Check BP on regular basis and report significant variations (and pulse)

Get out of bed slowly

Patient Teaching forAntihypertensive drugs Increase intake of potassium-rich

foods, unless taking potassium sparing diuretics

Weigh regularly and report abnormal weight gains or losses

Do not take OTC drugs without checking with healthcare provider

Special notes on Treatment of Hypertension.

Never combine: 1-Alpha or beta blocker and clonidine - antagonism 2-Nifedepine and diuretic synergism 3-Hydralazine with DHP or prazosin – same type of

action 4-Diltiazem and verapamil with beta blocker –

bradycardia 5-Methyldopa and clonidine

Hypertension and pregnancy: No drug is safe in pregnancy Avoid diuretics, propranolol, ACE inhibitors, Sodium

nitroprusside ..etc Safer drugs: Hydralazine, Methyldopa,

cardioselective beta blockers and prazosin

Hypertensive Crisis

Hypertensive Urgencies: No progressive target-organ dysfunction. (Accelerated Hypertension)

Hypertensive Emergencies: Progressive end-organ dysfunction. (Malignant Hypertension)

Hypertensive Urgencies Severe elevated BP in the upper

range of stage II hypertension. Without progressive end-organ

dysfunction. Examples: Highly elevated BP

without severe headache, shortness of breath or chest pain.

Usually due to under-controlled HTN.

Hypertensive Emergencies Severely elevated BP (>180/120mmHg). With progressive target organ

dysfunction. Require emergent lowering of BP.

Examples: Severely elevated BP with: - Hypertensive encephalopathy -Acute left ventricular failure with

pulmonary edema -Acute MI or unstable angina pectoris -Dissecting aortic aneurysm

Hypertensive Emergencies 1-Cerebrovascular accident or head injury with high BP 2-Hypertensive encephalopathy 3-Angina or MI with raised BP 4-Acute renal failure with high BP 5-Eclampsia[ pregnancy hypertension ] Drugs:

Sodium Nitroprusside (20-300 mcg/min) – dose titration and monitoring

GTN (5-20 mcg/min) – cardiac surgery, LVF, MI and angina Esmolol (0.5 mg/kg bolus) and 50-200mcg/kg/min - useful

in reducing cardiac work

The End