Pharmacological mechanism-based classification Diuretics: Thiazide-Hydrochlorothiazide Loop-furosemide,torsemide,ethacrynic acid Potassium-sparing-amiloride,spironolactone,triamterene Sympathoplegic agents Adrenergic synthesis/release blockers-reserpine,granethidine Central a-adrenergic agonists-a-methodopa,clonidine a-blockers-prazosin,tetrazosin,doxazosin B-blockers-propranolol,nadolol,timolol,metoprolol,acebutolol,penbutolol,pindolol Ganglion blocker-Trimethaphan Direct vasodilators:hydralazine,minoxidil,sodium nitroprusside,diazoxide Calcium channel blockers:nifedipine,amlodipine,felodipine,diltiazem,verapamil AT-lI antagonists ACE inhibitors: ACE inhbitors-captopril,enalapril,enalaprilat,lisinopril,benazepril AT-lI receptor antagonists-losartan DIURETICS First-line drug for hypertension.Relatively safe and effective. Suitable for older adults.Can be given orally.Use alone or with other antihypertensive agents.Low cost and mostly available in 3rd world countries. Mechanism of action: Diuretics lower BP by depleting body sodium stores.Full effects take 2 steps:(1)initial reduction of total blood volume and hence cardiac output;peripheral vascular resistance may increase;(2) when CO returns to normal(takes 6-8 weeks),PVR declines. 44 Pharmacological mechanism-based classification Diuretics: Thiazide - Hydrochlorothiazide Loop - furosemide, torsemide, ethacrynic acid Potassium-sparing - amiloride, spironolactone, triamterene Sympathoplegic agents : Adrenergic synthesis / release blockers - reserpine, granethidine Central α-adrenergic agonists – α-methodopa, clonidine α−blockers - prazosin, tetrazosin, doxazosin β−blockers - propranolol, nadolol, timolol, metoprolol, acebutolol, penbutolol, pindolol Ganglion blocker - Trimethaphan Direct vasodilators: hydralazine, minoxidil, sodium nitroprusside, diazoxide Calcium channel blockers: nifedipine, amlodipine, felodipine, diltiazem, verapamil AT-II antagonists & ACE inhibitors: ACE inhbitors – captopril, enalapril, enalaprilat, lisinopril, benazepril AT-II receptor antagonists - losartan I. DIURETICS First-line drug for hypertension. Relatively safe and effective. Suitable for older adults. Can be given orally. Use alone or with other antihypertensive agents. Low cost and mostly available in 3rd world countries. Mechanism of action: Diuretics lower BP by depleting body sodium stores. Full effects take 2 steps: (1) initial reduction of total blood volume and hence cardiac output; peripheral vascular resistance may increase; (2) when CO returns to normal (takes 6-8 weeks), PVR declines