Antihypertensive Therapy.pdf

Management of Hypertension Dr. Khloud Salem; MD 1. Lifestyle Management: Healthy diet: Low fat, high Weight reduction: Aim for BMI < 25. fiber. Salt restriction: Low sodium,...

Management of Hypertension Dr. Khloud Salem; MD 1. Lifestyle Management: Healthy diet: Low fat, high Weight reduction: Aim for BMI < 25. fiber. Salt restriction: Low sodium, Smoking cessation high potassium. Stress management Alcohol restriction: Reduce intake to moderate levels. Exercise: Moderate intensity, such as walking or cycling. 2. Antihypertensive drugs: 4 main classes (ABCD) Add on drugs  RAAS blockers (ACEIs& ARBS)  Mineralocorticoid antagonist MRA  Beta blockers  Alpha blockers  Calcium channel blockers  Direct vasodilators  Diuretics  Centrally acting drugs A. RAAS blockers (ACEIs& ARBS) ACEIs: ARBS Suffix  pril  sartan (Captopril, Enalapril, Esinopril, (Losartan &Valsartan) Ramipril & Perindopril) Mechanism of Inhibit ACE, prevent converting of Block angiotensin II action inactive angiotensin I to active receptors angiotensin II Effect VD, salt & water excretion VD, salt & water excretion Side effects dry cough, angioedema teratogenicity, hyperkalemia teratogenicity, hyperkalemia contraindications:  pregnancy, lactation  Bilateral renal artery stenosis  Worsening renal function  LVOT obstruction  Angioedema Notes - never combine two RAAS blockers for the same patient - ARBS can be used in patient who can`t tolerate ACEIs 1 B. B-Blockers: suffix (lol) Types Non-selective (B1&B2 Cardio selective Vasodilating blockers) (B1blockers) (α1& B blockers) Examples propranolol metoprolol, carvidolol, atenolol, nebivolol bisoprolol, esmolol Mechanism of Block B receptors in heart and blood vessels action B1 blockers negative inotropic (decrease COP) Effect B2 blockers vasodilators (decrease PR) Side effects Bradycardia Bronchospasm Erectile dysfunction Mask symptoms of hypoglycemia Contraindications Heart block Bronchial asthma, COPD Acute heart failure Vasospastic angina C. Calcium channel blockers: Types: Dihydropyridines Non-dihydropyridines Suffix pine Verapamil Amlodipine Diltiazem Nifedipine Nicardipine Mechanism of action Inhibit Ca channels in cardiac myocytes and vascular smooth muscles Effect Vasodilators -ve inotropic & chronotropic effect Side effects Ankle edema Bradycardia &Heart block Gingival hyperplasia Orthostatic hypotension Contraindications Bradycardia &Heart block & sick sinus &Heart failure 2 D. Diuretics: Types loop diuretics Thiazide & thiazide like Examples furosemide & torsemide (metolazone) Effects  salt & water excretion>>>> decrease blood volume  Vasodilatation>>> decrease peripheral resistance Side effects  Hypokalemia  Hyponatremia  Hyperuricemia  Hyperlipidemia  Hypocalcemia  Hypercalcemia E. Mineralocorticoid receptor blockers (MRA) & K sparing diuretics Examples Spironolactone Eplerenone Finrenone (Suffix: non) Mechanism of action Block aldosterone receptors Effects  increase Na, water excretion & K retention Side effects  hyperkalemia,  teratogenicity,  gynecomastia,  menstrual irregularities Contraindications  severe renal or hepatic failure  pregnancy and lactation Precautions  Be cautious when used with other drugs that cause hyperkalemia (RAAS blockers) F. Alpha antagonists: Examples Prazosin, doxazosin, Tamsulosin (Suffix: sin) Mechanism of action Block α1 receptors in arterioles (and venules) → VD → ↓ PVR. Uses  For resistant hypertension (with other drugs)  Men with concurrent HTN & benign prostatic hyperplasia. Side effects  Reflex tachycardia & Orthostatic hypotension & First-dose phenomenon Precautions  first dose→ small & at bedtime 3 g. Centrally acting drugs Examples Clonidine & Alpha methyldopa Mechanism of action Activate presynaptic α2-adrenoceptors in the medulla → ↓ sympathetic outflow from the central vasomotor center to the blood vessels & heart →↓ peripheral vascular resistance Uses - For resistant hypertension (with other drugs) - Methyldopa → used to treat HTN in pregnant women → it does not harm the fetus Side effects - Sedation& impaired mental acuity & dry mouth - Severe rebound hypertension if they are discontinued abruptly - Methyldopa → cause autoimmune Coombs-positive hemolytic anemia & autoimmune hepatitis. Precautions Stoppage: dosage should be ↓ gradually over 1 to 2 weeks h. Vasodilators Examples Hydralazine Mechanism of action Directly relax vascular smooth muscle only in the arteries → arterial VD & ↓ peripheral vascular resistance. Uses HTN during pregnancy Side effects Hydralazine-induced lupus erythematosus (a lupus-like syndrome) Notes must be combined with diuretics and β-blockers 4 Fig. 1: Algorithm for a patient screened for or confirmed hypertension 5  Fig. 2: Treatment approach for a diagnosed hypertensive patient. 3. Management of secondary HTN: Aortic coarctation Surgery Endocrinal disorders Medical & surgical Obstructive sleep apnea Sleep therapy 6 4. Management of Resistant Hypertension Definition: Failure to achieve target BP despite using 3 antihypertensive drugs, including a diuretic. Causes of pseudo-resistance: White coat HTN, poor adherence, improper BP measurement. Diagnosis: by ABPM or HBPM After exclusion of pseudo-resistant & secondary HTN Algorithm for Treatment: o Reinforce lifestyle measures. o Add spironolactone (MRA). o Add bisoprolol or centrally acting drugs. o Consider alpha-blockers. 7 5. Management of Hypertensive Emergencies Definition: BP > 180/110 mmHg with signs of acute hypertensive organ damage (e.g., stroke, heart failure). Emergency Urgency HTN > 180/110 with evidence of acute HMOD HTN >180/110 without signs of HMOD Require hospital admission, immediate intervention Don`t require admission, managed by oral drugs - Acute HMOD: - Acute heart failure Papilloedema - hypertensive pulmonary edema - Myocardial infarction Hypertensive encephalopathy Aortic dissection Preeclampsia Treatment: o ICU admission. o IV Medications: nitroglycerin, nicardipine, labetalol, Mg sulphate for preeclampsia. o Supportive care: Oxygen, monitoring of target organs. o Correction of any precipitating cause 6. Hypertension in Specific Populations Chronic Kidney  When e GFR>> use loop diuretics Disease (CKD) not thiazide  Follow up of K level when using RAAS blockers Coronary  B blockers is preferred from the start Artery Disease (CAD) Heart Failure  RAAS blockers & B blockers & MRA are preferred  Avoid negative inotropic CCBs  Adjust diuretic dose according to congestive symptoms Pregnancy  Methyl dopa & labetalol & oral nifedipine  IV hydralazine in resistant cases  Mg sulphate, IV labetalol & nicardipine in eclampsia  RAAS blockers & MRA contraindicated Acute stroke &  BP should be decreased to less than 180/105 in patients intracerebral who will receive thrombolytic therapy and maintained hemorrhage for the first 24 hrs  In hemorrhage decrease BP to (140-160 mmHg) within 6 hrs 8  Comparison of important classes of antihypertnsives. Drug Class Examples Mechanism Side Effects Contraindications RAAS ACEIs (Captopril, Inhibit RAAS, Cough (ACEIs), Pregnancy, Bilateral Blockers Enalapril), ARBs ↓vasoconstriction hyperkalemia, renal artery stenosis (Losartan) teratogenicity Beta- Metoprolol, ↓heart rate, negative Bradycardia, Asthma, heart block, blockers Propranolol inotropic effect bronchospasm, acute heart failure hypoglycemia masking Calcium Amlodipine, Vasodilation Edema, gingival Bradycardia, heart Channel Verapamil (dihydropyridines) hyperplasia failure (non- Blockers (dihydropyridines) dihydropyridines) Diuretics Furosemide, ↓blood volume, Hypokalemia, Severe renal failure, Thiazide ↓peripheral resistance hyperuricemia, electrolyte disturbances hyperlipidemia Add-on Spironolactone Aldosterone blockade Gynecomastia Pregnancy, severe Drugs (MRA) hepatic or renal failure alpha blockers vasodilation orthostatic hypotension 9