33 Antihypertensives

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• antihypertensives work by either decreasing CO or decrease TPR

Beta Blockers

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• do not want to block b2

• not really used for hypertension

• b1 blockade: general lower BP, including portal system

• b2 increase flow to liver, block to decrease flow

• carvedilol: clinical trial shows benefit, not because of special receptor

• at low sympathetic level, higher activation of beta receptor than sympathetic activity, thus agonist

• high level, lower activation of beta receptor than sympathetic, thus blocker

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• fatigue, etc: blunt CNS activity

• hyperlipidemia not clinically relevant

• given because many benefits

• diabetics often hypoglycemic because taking insulin

• BB cause hypoglycemia and masks symptoms, except sweating (Ach receptors)

• decompensated

• acute HF: pt with pulmonary edema/sick from HF can get very sick with BB's lowering of CO

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• stimulates myocardiocytes at different site

• stimulate heart and bypass beta receptors

Alpha Drugs

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• tamsulosin very good for BPH

• warm autoimmune hemolytic anemia

CCB

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Dihydropyridines

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• pt not taking CCB: arteriole constrict, leading to lower hydrostatic pressure in capillaries

• CCB: dilate arteriole, higher hydrostatic pressure

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• like b1, slow HR, decrease contractility

AII

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• inhibits renin, decrease AI production

• HCTZ: used often for antihypertensives by inhibit Na absorption

Hydralazine

Hypertensive Emergency

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• rapid acting drugs that can be titrated carefully

• increased renal perfusion

Antihypertensive SE

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• diuretic pts: dependent on AII to maintain BP

• ACE I block AII

• occurs with first dose of ACE I given to diuretic pt

Choosing Antihypertensives

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• RAAS blockade leads to malformation

• ACE I: decrease AII, renal failure

• aldosterone decrease: more K