Antihypertensives Flashcards
What are examples of medications that are ACE inhibitors?
enalapril, fosinopril
What are examples of medications that are angiotensin receptor blockers?
losartan, candesartan
What are medications that are vascular calcium channel blockers? What about cardiac channel blockers?
Vascular: nifedipine, amlodipine
Cardiac: verapamil, diltiazem
What is an example of an alpha 1 receptor antagonist?
prazosin
What is an example of a alpha 2 receptor agonsit?
clonidine
What vasodilators are used to treat hypertension?
- hydralazine, minoxidil, nitroprusside
What is the formula that shows the regulation of blood pressure?
BP = cardiac output x total peripheral resistance
What does cardiac output depend on?
- venous return
- venous tone
- blood volume
- heart rate
- contractility
What does total peripheral resistance depend on?
- resistance vessel diameter
- arterial tone
Chronic increases in blood pressure is normally due to an increased ________
arterial resistance
90% of hypertension is considered to be _____ hypertension
essential (the cause is unknown)
10% of hypertension is considered to be from a ______
definable cause
What are some medications that can cause hypertension?
- estrogens (oral contraceptives)
- NSAIDS
- antidepressants, cyclosporin, amphetamines
- decreased compliance
What other medical conditions can cause hypertension?
- renal artery stenosis
- coarctation of the aorta
- phaeochromocytoma (catecholamine secreting tumor), primary hyperaldosteronism
What are the 3 mechanisms to correct a major decrease in blood pressure?
- decreasing RPP, therefore increasing sodium retention (this increases blood volume)
- Increasing RAAS, therefore increasing aldosterone (increase in TPR)
- Increase in SNA, therefore increasing NE (increases cardiac output)
What are the main non-pharmacological treatments of hypertension?
- sodium restriction
- weight loss (> 5 kg in those that are overweight)
- exercise (45-60 minutes of moderate activity 4-5/week)
- reduced alcohol intake (<2 drinks /day in those who drink excessively)
- smoking cessation
- relaxation
What is considered to be first line therapy for treating hypertension?
diuretics in uncomplicated hypertension
With diuretics, the dose response for blood pressure lowering is relatively ____
flat
(this means that increasing the dose will product little improvement in effect. Complications increase with dose- can cause hypokalemia, glucose intolerance, increased LDL)
What diuretic is useful in renal impairment and edematous states?
- loop diuretics
Are loop diuretics typically used as an antihypertensive?
No
Are loop diuretics a good choice for long term treatment?
No -they are fast onset and have a short action, and there is potential for extreme electrolyte imbalance
What is the clinical use of potassium sparing diuretics?
- useful with thiazides - decreases the potassium lost
- effective when increased BP due to mineralocorticoid excess
What diuretics typically will cause electrolyte problems?
- thiazides and loop diuretics
hypokalemia, hypercalcemia-thiazides, hypocalcemia-loop
What are some general side effects of thiazides?
- decreases insulin release- hyperglycaemia
- increased LDL levels (bad)
- increased incidence of erectile dysfunction
- vascular volume contraction (decreased blood volume)
What are some general side effects of using loop diuretics?
- deafness - if given with an aminoglycoside antibiotic
- vascular volume contraction- decreased blood volume
What are some general side effects of using potassium sparing diuretics?
- hyperkalemia
- estrogenic effects - gynecomastia, impotence
What is the mechanism of action of an ACE inhibitor?
- decerases TPR, decreases aldosterone (and increases Pk, useful?)
(ACE inhibitors are thought to be better because it also increases bradykinin which decreases blood pressure)
What is the mechanism of action of ARBs?
- blocks all receptors
- decreases total peripheral resistance, decreases aldosterone (and increases Pk, useful?)
Glucose levels in the blood are affected by ACEI’s and ARBs. True or false?
FALSE
What are some potential AE associated with ACEI’s or ARBs?
- rash, cough (ACEIs), hyperkalemia, proteinuria, angioedema
What is considered to be the first line single therapy for uncomplicated hypertension?
ACEIs or ARBs
ACEIs and ARBs are especially recommended if the patient has a concurrent condition such as what?
- heart failure
- left ventricle dysfunction
- post MI
- diabetes
- systolic dysfunction
- proteinuria (chronic kidney disease)
There is little reflex ____ with using ACEIs or ARBs - due to a decrease in NE release
tachycardia
There should be caution when using ACEIs or ARBs if the _______ are elevated q
angiotensin 2
Are ACEI or ARBs safe to use in pregnancy?
no
Are calcium channel blockers first line or second line in the management of hypertension?
- second line
What are the 2 classes of calcium channel blockers and what are some examples of them?
- vascular (dihydropridines) - amlodipine, nifedipine
2. cardiac and vascular (non-dihydropridines) - verapamil, diltiazem
Describe dihydropyridines. What are they used for specifically?
- have a greater affinity for vascular calcium channels
- used for angina, raynauds and hypertension
- reduce TPR without apparent cardiac actions
- diuretics may block nifedipine effects on BP
- used for hypertensive crisis
Describe non-dihydropyridines. What are they used for?
- used in hypertension if also concern about heart rate control in atrial fibrillation or in patients with angina
Diltiazem is used to treat ___ and _____
angina and hypertension
both vascular and cardiac effects
What is the action of verapamil?
- blocks mainly in the heart (limited vascular tissue)
- should not be combined with a beta adrenegeric receptor blocker (both drug classes block AV node)
- contraindicated in heart failure
When are calcium channel blockers especially useful?
- when beta blockers are contraindicated in obstructive airway disease or diabetes
- in the elderly and african americans
- low incidence of side effects, but expensive
- neutral metabolic profile
What are the adverse effects associated with calcium channel blockers?
- headache, flushing, edema, constipation
- increased mortality post MI with short acting preparations
- should NEVER decrease BP rapidly
- published concerns about the increased risk of cancer to increased GI bleeding seem unfounded
Can calcium channel blockers be used with angina pectoris, raynaud’s phenomenon, asthma or COPD?
Yes
How can you tell whether or not a beta blocker is working?
- if you take the blood pressure of a person sedentary, and then you take the blood pressure of a person that has some exercise, there should be no increase
There is an increased incidence of what with B-adrenergic receptor antagonists?
- type 2 diabetes
Are beta blockers useful as mono therapy?
NO, it is not useful
- if a person is only hypertensive, lowers blood pressure but unclear if decrease in cardiovascular mortality
- useful as a second drug however - blocks reflex activation of the heart by the SNS (mostly used only in post MI/heart failure)
Are beta blockers considered metabolically neutral?
- no, they are not
- they can increase TGs potentially and decrease HDLs
Beta blockers cause an increased incidence of what 2 conditions?
- erectile dysfunction
- increased incidence of type 2 diabetes
Should avoid the use of beta blockers in what conditions?
- asthma, COPD, peripheral vascular disease, insulin dependent diabetes, physical activity?
Beta blockers are good to use in what conditions?
- glaucoma, supraventricular arrhythmia, heart failure, MI, angina
Describe the use of prazosin (a alpha adrenergic receptor antagonist) in hypertension?
- not effective as a single agent for chronic BP lowering (vasodilates the arteries and the veins)
- decreases insulin resistance
- useful in BPH
- shown to decrease nightmares in PTSD
What are the problems associated with alpha adrenergic receptor antagonists?
- fluid retention with long term treatment (give with a diuretic)
- first dose effect - initial large decrease in blood pressure
- orthostatic hypotension
Describe clonidine (alpha 2 receptor agonists)
- acts on the central vasomotor centres
- decreases sympathetic nerve activity form the CNS
- autonomic system remains intact - reflexes intact (orthostasis rare, given as 2 unequal doses)
- limited use- sedation and dry mouth
- rebound hypertension upon rapid cessation of the drug
- more common as adjunct to general anesthetic
Are vasodilators used alone for chronic blood pressure lowering?
No
When is hydrazine useful? (vasodilator)
- greater arteriolar effect
- give with beta blocker and diuretic
- used in pregnancy
What are the problems associated with hydralazine?
- may cause lupus-like syndrome
- may increase SNA - myocardial stimulation
- can cause headache, flushing nausea, hypotension, tachycardia, angina pectoris
When is minoxidil useful?
- arteriolar dilator
- give with a beta blocker and diuretic
- for severe hypertension (refractory)
- may cause pericardial effusion
- hirsutism
Describe the effects of sodium nitroprusside?
- venous and arteriolar dilator
- rapid onset, rapid offset
- blood pressure is titratable
- for hypertensive encephalopathy
- potential for cyanide toxicity
What should be used as mono therapy in younger patients?
- respond best to ACEI, ARB or beta adrenergic receptor antagonist - BUT beta adrenergic antagonist may be inferior to protect from a stroke
What should be used as mono therapy in black patients and elderly patients?
- respond best to thiazide diuretics or long acting CCBs
- however, patients may have other indications that suggest the need for ACEI or ARB (heart failure, post MI)
