Antihypertensives and Diuretics

Question 1

ACEI

Answer 1

treatment of HTN and CHF
management of post myocardial infarction pt
frequent once daily dosing
very common medication for your patient to be on

Question 2

RAAS

Answer 2

inhibition of converting angiotensin 1 to 2
renin is released from the JXA in response to low BO
Renin is responsible for converting angiotensinogen to angiotensin 1
Angiotensin 2 is a powerful vasopressor that also stimulates the release of norepi and aldosterone
Endogenous angiotensin 2 raises BP and decreases CO
Water and sodium retention are secondary to elevated aldosterone

Question 3

frequent ACEI side effects

Answer 3

cough from bradykinins
hypotension
rash
acute renal failure (with renal artery stenosis)
angioedema
increased fetal mortality

Question 4

ARB MOA

Answer 4

block angiotensin receptor
interferes with binding to angiotensin 2 receptors preventing the formation of angiotensin 2
Effects similar to those of ACEI, but much better tolerated by individuals with lung disease (do not cause cough seen frequently with ACEI)

Question 5

ARBS

Answer 5

“-sartans”
directly bind to AT2 receptors
can be more difficult to manage under anesthesia
no kinase mediated cough though

Question 6

Osmotic diuretics

Answer 6

mannitol
mannitol is completely filtered at the glomeruli
increases the osmotic gradient and prevents fluid reabsorption

Question 7

thiazide diuretics MOA

Answer 7

• affect the distal renal tubular mechanism interfering with normal electrolyte reabsorption
• Increase excretion of sodium and potassium
• incidental loss of bicarbonate ions
• effects can last up to 12 hours post dosage
• eliminated by the kidney mostly unchanged

Question 8

thiazide diuretics

Answer 8

common use in essential HTN, often accompanied by other agents, MOA for HTN unknown, does nose hpotension in normotensive patients

Question 9

loop diuretics

Answer 9

Furosemide
Inhibit reabsorption of sodium and chloride ions
primary action is at ascending loop of henle

Question 10

Bumex

Answer 10

• ascending and descending loop activity
• used frequently in open heart surgery patients for sustained diuretic effects
• can cause rapid dehydration due to potent diuretic action
• hypokalemia and hyponatremia can occur