Pharmacology Antihypertensive Drug Therapy (ARBS, Beta Blockers, and Calcium Channel Blockers) Part 2
What is the prototype drug for ARBs?
Iosartan
What do all ARBS end in?
"-sartan"
What do ARBs do?
blocks angiotensin ll at various receptor sites and prevents effects of vasoconstriction and aldosterone secretion
What would you use ARBs for?
hypertension, DM, HF, post MI
What are some positives in ARBs compared to ACE inhibitors?
they don't produce a cough and angioedema is rare.
What should you absolutely NOT do with ARBs?
administer with ACE inhibitors. PRILS SHOULD STAY AWAY FROM SARTANS
ARBs have a BBw. What is it?
do not give to pregnant people
What are some side effects of ARBs?
A ↓ angiotensin ll effects, aldosterone, ADH
R ↓ resistance
B ↓ blood volume
What is the prototype drug for beta (andrenergic) blockers?
propranolol
What do beta blockers do?
blocks nor/epinephrine at beta-andrenergic receptors, thus decreasing heart rate and contraction
What would you use beta blockers for?
hypertension, stable angina, tachyarrhythmias, stable HF
Beta blockers have a BBW. What is it?
abrupt discontinuation = exacerbation of angina, dysrhythmias, MIs with pts that have CAD
What are some side effects of beta blockers?
BETABLOCKS
Calcium channel blockers have 2 categories. What are they?
1. dihydropyridines ("-ine")
2. non-hydropyridines
What are some calcium channel blocker drugs?
verapamil, nifedipine, diltiazem
What is the prototype drug for dihydropyridines?
amlodipine
What does amlodipine do?
it decreases the influx of calcium ions in smooth muscle of blood vessels (relaxes/dilates arteries)
What are some uses for dihydropyridines?
treats hypertension, angina, conditions with vasoconstriction/vasospasms
What are some non-dihydropyridine drugs?
verapamil and diltiazem
What do non-dihydropyridine drugs do?
decrease the influx of calcium ions in cardiac cells and pacemaker cells leading to decreased conduction and heart rate. It also decreases contractility.
What would you use non-dihydropyridine drugs for?
hypertension, angina, and tachyarrythmias
What are some side effects for dihydropyridine drugs?
edema (peripheral and pulmonary = flushing/reflex tachycardia).
increases vasodilation while decreasing heart function.
What are some side effects for non-dihydropyridine drugs?
bradycardia. rare = arrythmias, heart block, HF.
What patients should use caution with non-dihydropyridine drugs?
those with bradycardia, HF, and using BBs. DO NOT USE NDPs WITH BBs.
What is a possible food interaction for CYP3A4 inducers?
St. John's worts (decreases effectiveness)
What is a possible food interaction for CYP3A4 inhibitors?
grapefruit juice (will increase plasma concentration)
What is some patient education on how to relieve edemas with dihydropyridines?
compression socks, ambulate, elevate extremity
What are some adjunct medications for hypertension?
SNS - alpha adrenergic receptos blockers - prazosin
RAAS - direct renin inhibitors - aliskiren
-aldosterone antagonists
Direct vasodilators - nitroprusside
- hydralazine
What is an urgent hypertensive crisis?
>180/>120 mmHg with no organ damage
Outpatient management: urgent care
Treatment: BP lowered over the course of hours/days
What is an EMERGENCY hypertensive crisis?
>180/>120 mmHg with organ damage
s/s- headache, difficulty speaking, vision changes, weakness, chest pain, SOB, hematuria
Treatment: controlled lowering of BP (not to normal levels tho bc it can lead to ischemia) in min/hours with oral meds like beta blockers (laretalol) and/or Iv meds like sodium nitroprusside
What is the prototype drug for direct acting vasodilators?
sodium nitroprusside
How does sodium nitroprusside work?
it directly relaxes the smooth muscle in blood vessels to dilate and decreases peripheral vascular resistance
What would we use sodium nitroprusside for?
to manage a hypertensive emergency
What are some side effects of sodium nitroprusside?
nausea, agitation, twitching
What are some nursing considerations for sodium nitroprusside?
It's given via IV and requires continuous BP monitoring. It has a rapid onset and a short duration. It converts to thiocyanate in liver (can lead to cyanide toxicity (s/s - coma, dilated pupils, pink color) so monitor the thiocyanate levels.
What are some general nursing considerations for antihypertensive meds?
get complete health hx, monitor labs (electrolytes, CBC, BUN/Cr/urinalysis, LFTs, lipid panel), monitor BP before/after administration, start on lowest effective dose, if BP unmanaged with monotherapy, use combo therapy at lower dose, taper slowly, DO NOT DISCONTINUE ABRUPTLY
What is some pt education given for antihypertensives?
Lower your sodium, caffeine, alcohol intake and try not to use any vasodilating hot baths/showers, hot tubs, sauna, DO NOT STOP ABRUPTLY. Assess compliance. Stop smoking and manage your weight.