33 Antihypertensives

  • antihypertensives work by either decreasing CO or decrease TPR

Beta Blockers

  • 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

  • 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

  • stimulates myocardiocytes at different site
  • stimulate heart and bypass beta receptors

Alpha Drugs

  • tamsulosin very good for BPH

  • warm autoimmune hemolytic anemia

CCB

Dihydropyridines

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

  • like b1, slow HR, decrease contractility

AII

  • inhibits renin, decrease AI production

  • HCTZ: used often for antihypertensives by inhibit Na absorption

Hydralazine

Hypertensive Emergency

  • rapid acting drugs that can be titrated carefully

  • increased renal perfusion

Antihypertensive SE

  • 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

  • RAAS blockade leads to malformation
  • ACE I: decrease AII, renal failure
  • aldosterone decrease: more K