Hypertension Flashcards
Hypertension stages
Normal BP : 120 /80
Prehypertension : 120-139 / 80-89
Hypertension I : 140-159/ 90-99
Hypertension II: > 160/100
Risk factors for Hypertension
Secondary hypertension Family history Obesity Smoking Sedintery Lifestyle Diabetes Dyslipidemia Micro albumin uria / GFR < 60ml/min Age > 55 men,. > 65 women
Hypertension types
Primary: cause unknown , above 90% cases, age 35 and above
Secondary: 2- 5 % cases, underlying disease, age 30 and above
Target organ damage in HTN
Brain Kidney (renovascular damage, kidney damage) Heart Brain Peripheral arterial disease
Blood pressure formula
Cardiac output x Total Peripheral Resistance (TPR)
Cardiac Output = stroke volume x heart rate
Physiology of hypertension
Sympathetic Nervous system:
Baroreceptors (carotid & aortic arch) —> respond to change in BP. Symp system causes them to constrict–> contraction force increase, HR increase, causing hypertension
Renin- Angiotensin- Aldosterone System:
Renal hypotension –> kidney releases renin–> renin enzyme for angiotensin to make angiotensin I –> angiotensin I to Angiotensin II by ACE (in pulmonary endothlium) –> Angiotensin II potent vasoconstrictor & releases Aldosterone from Adrenal gland–> Aldosterone
Aldosterone function:
Reabsorption of Sodium and water thus Blood volume increase .
releases ADH and Vasopressin (Pituitary)
Myocardial hypertrophy & vascular hypertrophy
Facilitate release and inhibit uptake of nor Adrenaline
Mosaic theory: many factors
Genetics, endothelial dysfunction, bradykinin, nitric oxide, ANP
Fluid Volume regulation: increased fluid volume increase TPR
Secondary HTN causes
Cushing Syndrome Pheochromocytoma Drug induced Chronic kidney disease Renal Artery Stenosis Primary Aldosteronism Thyroid , parathyroid disease
Drugs that induce secondary HTN
Corticosteroids (chronic) Estrogen and oral contraceptive NSAIDs Nasal decongestant TCA MAOs Appetite suppressants Cyclosporine Erythropoietin
Lab findings in Secondary HTN
RFT:
BUN, creatinine elevation
Urinary test:
Vanilyll mandelic acid & metanephrine ( pheochromocytoma)
Hyperkalemia (primary Aldosteronism or Cushing Syndrome)
Renal arteriography, Ultrasound or renal venography
ECG
JNC Target BP for patients with diabetes or renal disease
130/80 mmHg
Thiazide Diuretics Classification with brand names
Chlorothiazide (Diuril) Hydrochlorothiazide (Microzid, hydroDiuril) Polythiazide ( Renese) Metyclothiazide Chlorthalidone Metolazone (Zaroxolyn, Mykrox) Indapamide (Lozol)
Doses for thiazide Diuretic JNC 7
mg/day
Chlorthiazide 125 - 500 Chlorthalidone 12.5 - 25 Hydrochlorothiazide 12.5 - 50 Polythiazide 2-4 Indapamide 1.25 - 2.5 Metolazone mykrox 0.5 - 1.0 Metolazone Zaroxolyn 2.5 - 5
Mechanism thiazide Diuretics
Urinary excretion of Sodium & water & chloride reabsorption
Urinary excretion of potassium & little bit Bicarbonate
Increase effect of other antiHTN by reducing and preventing more blood volume
Interaction of thiazide Diuretics
NSAIDs
Reduce effect of diuretic
Side effects thiazide Diuretics
Hypokalemia Hypomagnesemia Uric acid retention Hyperglycemia Hypercalcemia Fatigue , headache, palpitations, rash, vertigo, transitory impotence Hyperlipidemia Dehydration Hypovolemia in extreme cases
Loop Diuretics Classification
Bumetanide ( Bumex)
Furosemide (Lasix)
Torsemide (Demadex)
Ethacrynic Acid (Edecrin)
Loop Diuretics mechanism
Act on ascending loop of Henle
Decrease Na reabsorption
Intense action but short acting
Interaction loop Diuretics
NSAIDs
Side effects loop Diuretics
Hypokalemia
Hypovolemia
Renal function monitoring BUN & creatinine
Transient Deafness (especially with Amino glycoside)
Doses Loop Diuretics
Bumetanide 0.5 - 2
Furosemide 20 - 80
Torsemide 2.5 - 10
Ethacrynic Acid 25 - 100
Potassium Sparing diuretics classification
Spironolactone (Aldactone)
Amiloride ( Midamor)
Triamterene (Dyrenium)
Eplerenone ( Inspra)
Interaction K sparring
ACE inhibitors
Potassium Supplement
Precautions sode effects
Acute renal failure hyperkalemia
Not in patients of recent kidney stones or hepatic disease
Doses K sparring diuretic
Amiloride 5 - 10
Spironolactone 25 - 100
Triamterene 50 - 100 mg
Eplerenone 50 - 100
B Blockers Classification
Atenolol (Tenormin) Acebutolol (Sectrat) Betaxolol (kerlone) Bisoprolol (Zebesta) Carvedilol (Coreg) Labetalol (Normodyn, Trandate) Metoprolol (Lopressor) Metoprolol ER (toprol xl) Nadolol (cograd) Penbutolol (levatol) Pindolol Propranolol ( Inderal) Timolol (Blocarden)
B blockers side effects
Cardiac decompensation due to decrease heart rate
ECG monitor for bradyarrythemia
Asthma COPD
Withdrawal (dose should be started and ended with titration)
Impotence
Caution in patients with:
Diabetes (masks hypoglycemia)
Raynaud phenomenon
Neurology disorders : fatigue lethargy, poor memory, weakness, depression
Propranolol
Inderal
B blocker non selective
40 - 160 mg
Rapid acting and long acting dosage form
Metoprolol
Lopressor
Toprol XL (sustained release)
Selective b1 blockage
50 - 100 mg /day
Timolol
Blocarden
Prevents death in Acute MI
Non selective blocker
20 - 40 mg
Labetalol
Labetalol effective in hypertensive crisis
a b both
Labetalol 200 - 800
Esmolol
Brevibloc
Ultrashort action
Used in surgery for htn and tachycardia
150 - 300 mcg/kg/min
Peripheral a blockers
Prazosin (Minipress)
Terazosin( hytrin)
Dixazosin( Cardura)
a blocker action
Indirect vasodilator
Block postsynaptic a adrenergic receptors
Causing vasodilation both arteries and veins
Low incidence of reflex tachycardia tham direct vasodilator
No adverse effects on lipid serum and other cardiac risks
Precautions in a blockers
First dose risk
Doses a blocker
Prazosin 2 - 20
Terazosin 1- 20
Dixazosin 1 - 16
Centrally Active A agonist
Methyldopa (Aldomet)
Clonidine (catapress)
Reserpine
Guanfacine (Terex)
Methyldopa side effects
Orthostatic hypotension Fluid accumulation Rebound hypertension Sedation Fever flu like symptoms Positive Coombs test. 1% develops reversable hemolytic anemia. Dry mouth Lactation in either gender Impotence Depression
Clonidine
Catapres
Effective in patients with renal impairment
Stimulation of a2 rec centrally to decrease heart rate
Initial paradoxical i crease in BP followed by a prolonged decrease
Sedation and dry mouth
Worsen depression
Dose 0.1 to 0.8 mg
Guanabenz & Guanfacine
Centrally acting a² agonist When initial therapy fails Sedation dry mouth bradycardia dizziness Caution in Coronary insufficiency MI CVA hepatic renal patients Dose 1 - 3 mg
Postganglionic Neuron blockers
Best avoided. Unless there’s severe refractory hypertension unresponsive to all other therapy
Reserpine (0.05mg) in combo with diuretic
Central acting, depletes catecholamines stores in brain and periphery
Can cause severe depression that lingers for months after last dose
Peptic ulcer contra
ACE inhibitors
Benazapril (Lotensin) Captopril ( Capoten) Enalapril (Vasotec) Fosinipril Lisinopril (zestril) Moexipril (Univasc) Perindopril (Aceon) Quinapril (Accupril) Ramipril (Altace) Trandola pril (Mavick)
ACE mechanism
Disrupts Renin Angiotensin Aldosterone System by inhibition of ACE . Thus Angiotensin II is decreased. No aldosterone
ACE inhb interactions
NSAIDs
Potassium Sparring diuretic ( hyperkalemia)
Adverse effects
Neutropenia (renal or autoimmune disease) Proteinuria (renal disease) Hyperkalemia Renal insufficiency, renal stenosis Dry cough Dysgeusia (altered taste) Rashes Vertigo Headache fatigue First dose hypotension Minor GI disturbance
Captopril
Capoten
12.5 to 25 mg 3 times daily
Increased to 25 to 100
Enalapril
Vasotec
Prodrug
Enalaprilat (active)
5 mg daily increased upto 40 mg later
Enalaprilat drug readily available. Used to treat acute hypertension crisis
Lisinopril
Zestril
Long acting analog of enalapril
5 to 10 mg. Later 10 to 40 mg
ARBs
Angiotensin II inhibitors Azilsartan (Edarbi) Candesartan (Atacand) Eprosartan( Teveten) Irbesartan (Avapro) Losartan (Cozaar) Olmesartan (Benicar) Telmisartan( micardis) Valsartan (Diovan)
Ca channel blockers
Amlodipine (Norvasc) Clevidipine (cleviprex) Diltiazem (cardizem) Felodipine (plendil) Isradipine (DynaCirc CR) Nicardipine (Cardene SR) Nifedipine (procardia XL) Nisoldipine (Sular) Verapamil (Calan)
Action ca channel blockers
Ca channel blocker inhibit influx of Ca throw slow channel in vascular smooth muscle and cause relaxation
Best response in black, low renin hypertensive and elderly patients
Ca channel blockers interaction
B blocker
Adverse effects
SA AV node disturbance contra Digitalis toxicity contra Nifedipine association with Headache, flushing, peripheral edema. Sustained release dosage lowers these effects Verapamil causes constipation
