Cardiovascular Flashcards
What are the common indications for Calcium Channel Blockers?
HTN - 1st or 2nd line
- reduces risk of stroke, MI, and death from cardiovascular disease
Stable angina
- Symptom control
Supraventricular arrhythmias/tachycardia, atrial flutter, atrial fibrillation
- Controls cardiac rate
Amlodipine and, to a lesser extent, nifedipine are used for the first- or second-line treatment of ______
What class of drugs are they?
HTN
CCBs
Which CCBs are primarily used to control cardiac rate in ppl w/ supraventricular arrhythmias, including supraventricular tachycardia, atrial flutter and atrial fibrillation?
Diltiazem and verapamil
What is the MOA of CCBs?
Decreased Ca concencentarstios w/ in cells
What is the MOA of CCBs?
Decreased Ca concentrations w/ in cells, due to blocked entry in vascular + cardiac cells
Causing relaxation + vasodilation in arterial smooth muscle
Heart:
Dec myocardial contractility
+
Suppress cardiac conduction esp. @ AV node - dec ventricular rate
+
reduced after load
=
reduced myocardial oxygen demand hence preventing angina
What are the 2 classes of CCBs?
Dihydropyridines - vasculature selective
(Amlodipine + nifedipine)
Non-dyhydropyridines - heart selective
(Verapamil + Diltiazem(also effects vasculature))
Which CCB is the most cardio selective?
Verapamil
List adverse effects of Amlodipine + Nifedipine + Diltiazem
Ankle swelling
flushing
headaches
Palpitations
Due to vasodilation + compensatory tachycardia
List adverse effects of verapamil + Diltiazem
Constipation - common
Bradycardia
Heart block
Cardiac failure
Which type of CCBs should not be prescribed w/ β-blockers except under close specialist supervision?
Non-dihydropyridine calcium channel blockers (verapamil and diltiazem)
Prescribing verapamil/diltiazem in conjunction w/ β-blockers can result in what? (3)
Heat failure
Bradycardia
Asytole
Verapamil and diltiazem should be used with caution in patients with _____
poor left ventricular function
AV nodal conduction delay
Amlodipine and nifedipine should be avoided in patients with ________
Unstable angina
Severe aortic stenosis
What are the 3 indications for loop diuretics?
- Acute pulmonary oedema
Symptomatic relief of fluid overload;
- Chronic heart failure
- Other oedematous states -
(Renal disease/liver failure, may be given inconjunction w/ other diuretics)
Loop diuretics should be used in conjunction w/ what 2 things to relieve breathlessness in acute pulmonary oedema?
Oxygen and nitrates
Which part of the nephron do loops diuretics act on?
What is the MOA there?
Ascending limb of the loop of Henle
inhibit the Na+/K+/2Cl− co-transporter
what does the inhibit the Na+/K+/2Cl− co-transporter protein do in the renal tubule?
transports sodium, potassium and chloride ions from the tubular lumen into the epithelial cell;
Water then follows by osmosis
Name 2 loop diuretics
Furosemide
Bumetanide
How do loop diuretics affect blood vessels?
How is this relevant in acute heat failure?
They dilate capacitance veins
Reduces preload and improves contractile function of the ‘overstretched’ heart muscle.
Water loss in loop diuretics can lead to which 3 adverse effects?
Dehydration
Hypotension
Low electrolyte states
(i.e. hyponatraemia, hypokalaemia, hypochloraemia, hypocalcaemia, hypomagnesaemia and metabolic alkalosis).
Why can high doses of loop diuretics cause hearing loss and tinnitus?
A similar Na+/K+/2Cl− co-transporter is responsible for regulating endolymph composition in the inner ear;
which gets affected at high doses
Loop diuretics are contraindicated in pts w/ severe _____ +_______
dehydration
hypovolemia
Loop diuretics should be used w/ caution in pts w/ which conditions?
Hepatic encephalopathy
Severe Hypokalaemia
Severe Hyponatraemia
Gout
Why can loop diuretics worsen gout?
If taken chronically they can inhibit uric acid excretion and it can worsen the gout
Why is loop diuretic use cautioned in ppl w/ hepatic encephalopathy?
The hypokalaemia can cause or worsen a coma
Loop diuretics have the potential to affect drugs excreted where?
List some specific drugs (3)
Drugs that are excreted by the kidneys
Lithium
Digoxin (bc diuretic associated hypokalaemia)
Aminoglycosides (inc ototoxicity + nephrotoxicity)
