Antihypertensive Drugs Blood Pressure Blood pressure CO SVR o CO cardiac output o SVR systemic vascular resistance Hypertension high blood pressure Four stages based on BP measurements 1 Normal 120 80 2 Prehypertension 120 139 80 89 3 Stage 1 hypertension 140 159 90 99 4 Stage 2 hypertension 160 100 Classification of BP Hypertension can also be defined by its cause Unknown cause o Essential idiopathic or primary hypertension o 90 of cases Known cause o Secondary hypertension o 10 of cases Autonomic Nervous System Parasympathetic nervous system Stimulates smooth muscle cardiac muscle glands Sympathetic nervous system Stimulates the heart blood vessels skeletal muscle Decreased volume Renin released Stim Angie I Convert to Angie II Vessel constriction o Increased BP Angie II stim secrete o Aldosterone Reabsorb Na and Water o Increased BP Antihypertensive Drugs Medications used to treat hypertension Categories o Adrenergic drugs o Angiotensin converting enzyme ACE inhibitors o Angiotensin II receptor blockers ARBs o Calcium channel blockers CCBs o Diuretics o Vasodilators o Direct renin inhibitors Adrenergic Drugs Five Subcategories Centrally and peripherally acting adrenergic neuron blockers Centrally acting alpha2 receptor agonists Peripherally acting alpha1 receptor blockers Peripherally acting beta receptor blockers beta blockers o Cardioselective beta1 receptors o Nonselective both beta1 and beta2 receptors Peripherally acting dual alpha1 and beta receptor blockers lol drugs are beta blockers Adrenergic Drugs Centrally acting alpha2 receptor agonists o Stimulate alpha2 adrenergic receptors in the brain o Decrease sympathetic outflow from the CNS o Decrease norepinephrine production o Stimulate alpha2 adrenergic receptors thus reducing renin activity in the kidneys o Result in decreased blood pressure o Clonidine Centrally acting alpha2 receptor agonists cont d o clonidine Catapres good emergency medication brings bp down very fast Doesn t last long Few side effects makes patient sleepy Peripheral alpha1 blockers antagonists Decreases peripheral vascular resistance All alpha1 blockers end in zosin o Block alpha1 adrenergic receptors o doxazosin Cardura o terazosin Hytrin also reduces size of the prostate Generally in older men lower bp and make them void less o prazosin Minipress Beta blockers o Reduce BP by reducing heart rate through beta1 blockade Slows heart rate o Cause reduced secretion of rennin o Long term use causes reduced peripheral vascular resistance o Examples nebivolol Bystolic propranolol Inderal atenolol Tenormin others o lol drugs Dual action alpha1 and beta receptor blockers o Reduce heart rate beta1 receptor blockade o Cause vasodilation alpha1 receptor blockade o carvedilol Coreg and labetalol Especially good for heart failure patients because it is cardioselective Good for patients with withdraw symptoms Slows them down o Result in decreased blood pressure Indications o All used to treat hypertension o Centrally acting alpha2 receptor agonists Treatment of hypertension either alone or with other drugs Usually used after other drugs have failed because of adverse effects Clonidine is useful in the management of withdrawal symptoms in opioiddependent persons Peripherally acting alpha1 receptor agonists o Treatment of hypertension o Some used to relieve symptoms of BPH o Management of severe heart failure HF when used with cardiac glycosides and diuretics Adverse Effects o High incidence of orthostatic hypotension Especially if given IV and used to lower cardiac output Fall precaution o Most common Bradycardia slowing heart rate with reflex tachycardia dry mouth drowsiness sedation constipation depression edema and sexual dysfunction All lol drugs o Other Headaches sleep disturbances nausea rash cardiac disturbances palpitations Angiotensin Converting Enzyme ACE Inhibitors Large group of safe and effective drugs Often used as first line drugs for HF and hypertension May be combined with a thiazide diuretic or calcium channel blocker Created from venom of South American viper First line Can be combined with other medications Lowering BP First drug of choice HCTZ Hydrocholrathyazoid o Diuretics to reduce water volume Second drug of choice Furosemide ACE inhibitors pril drugs ACE Inhibitors captopril Capoten benazepril Lotensin enalapril Vasotec fosinopril Monopril lisinopril Prinivil moexipril Univasc quinapril Accupril and others Mechanism of Action o Inhibit angiotensin converting enzyme which is responsible for converting angiotensin I through the action of renin to angiotensin II o Angiotensin II is a potent vasoconstrictor and causes aldosterone secretion from the adrenal glands o Block angiotensin converting enzyme thus preventing the formation of angiotensin II o Prevent the breakdown of the vasodilating substance bradykinin o Result in decreased systemic vascular resistance afterload vasodilation and therefore decreased blood pressure Indications o Hypertension o Heart Failure either alone or in combination with diuretics or other drugs o Slow progression of left ventricular hypertrophy after MI cardioprotective Slow enlargement of the heart o Renal protective effects in patients with diabetes Type II Diabetes patients will all be on an antihypertensive because it is renalprotective o Drugs of choice in hypertensive patients with HF o Drugs of choice for diabetic patients o Captopril and lisinopril number one and least costly are NOT prodrugs Prodrugs are inactive in their administered form and must be metabolized in the liver to an active form so as to be effective Captopril and lisinopril can be used if a patient has liver dysfunction unlike other ACE inhibitors that are prodrugs Adverse Effects o Fatigue initial Dizziness Headache Mood changes Impaired taste and Possible hyperkalemia Retain more potassium o Dry nonproductive cough which reverses when therapy is stopped 18 20 of patients o Angioedema rare but potentially fatal o ACE inhibitor will be less affective if the patient is on NSAIDS o First dose hypotensive effect may occur Angiotensin II Receptor Blockers Also referred to as angiotensin II blockers or ARBs Well tolerated Do not cause a dry cough o Created last o If ACE inhibitor causes too many side effects we give this o Can be taken with other drugs losartan Cozaar eprosartan Teveten valsartan Diovan irbesartan Avapro candesartan Atacand olmesartan Benicar telmisartan Micardis and azilsartan Edarbi o Sartan drugs Mechanism of Action o