Anti hypertensive Drugs
Anti hypertensive Drugs
OVERVIEW Hypertension is defined as a sustained diastolic blood pressure greater than 90 mm Hg accompanied by an elevated systolic blood pressure (>140 mm Hg)
OVERVIEW ◼ Hypertension is defined as a sustained diastolic blood pressure greater than 90 mm Hg accompanied by an elevated systolic blood pressure (>140 mm Hg)
Tab.1 Definitions and classifications of blood pressure levels. Category Systolic Diastolic Stroke mortality [mm Hgl (mm Hg] Relative risk Optimal <120 and <80 1.00 Normal <130 and <85 1,73 High normal 130-1390r 85-90 2.14 Hypertension Stage 1(mild) 140-1590r 90-99 3.58 Subgroup:borderline 140-149 90-94 Stage2(moderate) 160-1790r 100-109 6.90 Stage3(severe) 2180 or 2110 9.66 Isolated systolichypertension ≥140and<90 Subgroup:borderline 140-149 and <90 The higher cateory appies if systoliand diastolicblood presurevalues ofa patient fallintoifferentcatris
can lead to congestive heart failure, myocardial infarction,renal damage, and cerebrovascular accidents
◼ can lead to congestive heart failure, myocardial infarction, renal damage, and cerebrovascular accidents
ETIOLOGY OF HYPERTENSION more than 90%of patients have essential hypertension,a disorder of unknown origin affecting the blood pressure-regulating mechanism. ■Inheritance factors Environmental factors such as a stressful lifestyle,high dietary intake of sodium,obesity
ETIOLOGY OF HYPERTENSION ◼ more than 90% of patients have essential hypertension, a disorder of unknown origin affecting the blood pressure-regulating mechanism. ◼ Inheritance factors ◼ Environmental factors such as a stressful lifestyle, high dietary intake of sodium, obesity
MECHANISMS FOR CONTROLLING BLOOD PRESSURE In both normal and hypertensive individuals,cardiac output and peripheral resistance are controlled mainly by two overlapping control mechanisms:the baroreflexes mediated by the sym-pathetic nervous system, and the renin-angiotensin-aldosterone system
MECHANISMS FOR CONTROLLING BLOOD PRESSURE ◼ In both normal and hypertensive individuals, cardiac output and peripheral resistance are controlled mainly by two overlapping control mechanisms: the baroreflexes mediated by the sym- pathetic nervous system, and the renin-angiotensin-aldosterone system
Central nervous systom Stress Nucleus tractus soltarius Carotd chemoreceptors Cardiac output Vascular resistance Arteral efferents Na'K"Ca baroreceptors Atrial natriuretic peptde Cardicpumonary Sympathetic barorecoptors Endothelal factors Preload I (NaCl and H,0) Plasma renin angictensin ll Prostaglandins Kinins Renal regulation of NaCl and H.o
TREATMENT STRATEGIES Mild hypertension can often be controlled with a single drug. More severe hypertension may require treatment with several drugs that are selected to minimize adverse effects of the combined regimen. Treatment is initiated with any of four drugs depending on the individual patient:a diuretic, a [beta-blocker,an ACE inhibitor,or a calcium channel blocker
TREATMENT STRATEGIES ◼ Mild hypertension can often be controlled with a single drug. ◼ More severe hypertension may require treatment with several drugs that are selected to minimize adverse effects of the combined regimen. ◼ Treatment is initiated with any of four drugs depending on the individual patient: a diuretic, a •beta-blocker, an ACE inhibitor, or a calcium channel blocker
Beta-Blockers Decrease heart rate,stroke volume Centrally acting drugs Receptors 1,-imidazoline-receptorAgorists Decrease central symmpathetic outflow -) Norepinephrine Central sympathetic outfow o,-Receptors K'channel openers AT,-Receptors K'Channel n Alpha-Blockers Calcium channel blockers ACE inhibitors Calciun AT:-Antagonists channel(L-type) B2-Receptors Relaxation Vascular smooth Diuretics" muscle cell Thiazides (- Na non (-) 45a Loop diuretics(-)
DIURETICS Diuretics are currently recommended as the first-line drug therapy for hypertension. Low-dose diuretic therapy is safe and effective in preventing stroke, myocardial infarction,congestive heart failure and total mortality
DIURETICS ◼ Diuretics are currently recommended as the first-line drug therapy for hypertension. ◼ Low-dose diuretic therapy is safe and effective in preventing stroke, myocardial infarction, congestive heart failure and total mortality