antihypertensives and renal agents

• Vessels which transport oxygenated blood to arterioles:
• thick walled, elastic
• mostly smooth muscle
• sympathetic stimulation causes vasoconstriction

• Return unoxygenated blood to heart
• Thin walled, stretch
• Relies on skeletal muscle contraction and pressure changes
• Low pressure
• One way valves peripherally

• Join arterioles and veins
• Carbon dioxide and oxygen exchange
• nutrition and waste eschange

• Pressure exerted on artery wall
• determined by:
• Blood volume
• Cardiac output
• Arterial distensibility
• Peripheral vascular resistance

• Maintained by:
• Renin-angiotensin system
• Andreneric recptors in the vessel wall
• Baroreceptors in the vessel wall
• Baroreceptors in the carotid sinus, aorta, and medulla

Angiotensin I

Angiotensin II

• Pressure sensitive nerve endings which decrease Bp in response to stretching
• Aorta
• Carotid Sinus
• Medulla

• Alpha1-raise Bp
• Alpha2-lower Bp
• Beta1-raise Bp
• Beta2-lower Bp

Hypertension

Most common, no identifiable cause, no cure.

Due to another condition (chronic renal disease, adrenal tumor, oral contraception, conditions causeng fluid retention (edema) Can be cured with removal of problem

Causes damage to vessels

• Arteriole constriction increases peripheral vascular resistance wich increaces workload of left ventricle then left ventricular hypertrophy which leads to heart failure
• Sclerosis of vessels which narrows lumen which lowers blood flow that lowers tissue perfusion and possibly thrombosis.
• Usually occurs without symptoms

• Diet low in fats and carbohydrates
• Limit alcohol
• Weight loss if obese
• African-Americane have higher risk for HTN

• Accumulation of fluid in body tissues
• Fluid retention- accumulation of fluids due to heart and or kidney failure of liver disease
• Hypertension- increased Bp may be due to accumulation of fluids in the vascular system
• i.e. Increased fluid volume

• Beta blockers
• Adrenergic blockers
• Direct acting vasodilators
• Angiotensin II Converting Enzyme inhibitors (ACE inhibitors)
• Angiotensin II Receptor Antagonists
• Calcium channel blockers
• Diuretics

• Angina
• dysrhythmias
• HTN

To block beta 1 which lowers sympathetic response which lowers CO, vascular resistance, and renin

• atenolol (Tenormin)
• metoprolol(LoPressor)
• propranolol(Inderol)

To treat HTN

to block alpha receptors in the sympathetic NS causing vasodilation and lower Bp

• prazosin(Minipress)
• methydopa(Aldomet)
• clonidine(Catapres)
• labetalol(Trandate)

To treat moderate to severe HTN

Relax smooth muscle of blood vessels leading to vasodilation

• hydralazine(Apresoline)
• minoxidil(Rogain)
• nitroprusside(Nipride)

Treatment of HTN and CHF

Inhibit formation of angiotensin II and block release of aldosterone causing Na and water excretion and lower peripheral resistance

• benazepril (Lotension)
• lisinopril (Zestril)
• catopril (Capoten)