CV Medications

• Too much fluid in the system will increase BP

  • if on a diuretic, it drains the fluid from the body and their BP will decrease
• Endothelins are endogenous peptides used to help raise BP by constricting blood vessels
• Baroreceptor reflex corrects BP within seconds by altering cardiac output and peripheral vascular resistance
• Primary HTN is likely due to genetics and environmental factors
• HTN management

  • diuretics
  • sympatholytics drugs
  • Vasodilators
  • Renin-angiotensin inhibitors
  • Calcium channel blockers
• Diuretics

  • kidneys
  • reduces plasma fluid volume
• Sympatholytics

  • sympathetic division of ANS
  • reduce sympathetic influence on heart/peripheral vascular system
• Vasodilators

  • peripheral vasculature
  • Vasodilate which lowers vascular resistance
• Renin-Angiotensin Inhibitors

  • peripheral vasculature and other organs
  • ACE Inhibitor: prevents conversion of angiotensin I to angiotensin II
• Calcium channel blockers

  • limits calcium entry into vascular smooth muscle and cardiac muscle
  • reduce vascular smooth muscle contraction
• Thiazide diuretics act on distal tube of nephron in kidneys inhibiting sodium reabsorption
• Loop diuretics inhibit reabsorption of sodium and chloride from the loop of henle
• Potassium sparing dieretics prevent potassium secretion into the distal tubule and prevents hypokalemia
• Adverse effects of diuretics

  • fluid depletion; OH
  • Increased urinary frequency
  • Increased cardiac workload by activating renin-angiotensin system
  • weakness/fatigue
  • Heart workload decreases
• IDE = diuretics
• Diuretics

  • HCTZ
  • Lasix
• Sympatholytic drugs

  • beta blockers
  • alpha blockers
  • presynaptic adrenergic NT depleters
  • centrally acting drugs
  • ganglionic blockers
• Beta blockers

  • beta receptor antagonist in cardiac muscle
  • blocks beta 1 receptors
  • relaxes the HR and contractility
  • expect a 20-30 BPM reduction in max HR
• Alpha 1 contracts vascular smooth muscle and relaxes intestinal smooth muscle
• alpha 2 decreases GI motility and insulin secretion
• Beta 1 increases HR and contractility, increases kidney function
• Beta 2 bronchodilation, vasodilation, and reduces GI motility
• Beta 3 decreases heart contractility, reduces bladder contraction
• Alpha blockers block the alpha 1 receptor in smooth muscle to reduce peripheral vascular tone
• Alpha blockers may cause tachycardia and trigger baroreceptors to increase cardiac output to prevent passing out
• Presynaptic adrenergic inhibitors inhibit the release of norepinephrine from presynaptic terminals of peripheral adrenergic neurons

  • reduces heart excitation and relaxes peripheral vasculature
  • Can cause: bradycardia, arrhythmias, drowsiness
• Centrally acting agents inhibit sympathetic discharge from brainstem

  • adverse effects: dry mouth, dizziness, sedation
• Ganglionic blockers block synaptic transmission at autonomic ganglia

  • quickly causes vasodilation and reduces BP
  • Used in emergencies for an HTN crisis
  • Adverse effects: OH, urinary retention, visual disturbances
• Beta blockers end in LOL
• Alpha blockers end in SIN
• Presynaptic adrenergic inhibitor: reserpine (Novoresperpine)
• Centrally acting agents

  • Clonidine (catapres)
  • Guanabenz (Wytensin)
  • Methyldopa (Aldomet)
• Ganglionic blockers

  • mecamylamine (inversine)
  • Trimethanphan (arfonad)
• Vasodilator drugs directly vasodilate the peripheral vasculature which reduces vascular resistance

  • works directly on the vascular smooth muscle cells
  • used for emergencies
• Vasodilator side effects

  • reflex tachycardia
  • triggers baroreceptor reflex
  • OH
  • Dizziness
  • weakness
  • hair growth
• Minoxidil (Rogaine) is a vasodilator

  • side effects hair growth, also used as a off-label use for hair growth
• Vasodilators

  • Diazoxide (hyperstat)
  • Hydralazine (apresoline)
  • Fenoldopam (Corlopam)
  • Minoxidil (Loniten)
  • Nitroprusside (Nitropress)
• Renin-Angiotensin System Inhibitors

  • system involves endogenous substances that regulate sodium and water balance
  • Renin is released from kidneys when BP falls
• 1. Renin converts angiotensin to angiotensin I
  2. Angiotensin I converted to II
  3. II is a very powerful vasoconstrictor
  4. II causes aldosterone release from adrenal cortex
  5. increases sodium reabsorption from kidneys which increases fluid volume = increased BP
• Angiotensin is a peptide made in the liver and always circulating in the blood