Cardiovascular medication Flashcards
When are antihypertensive drugs prescribed?
When diet and physical activity changes are not successful or practical
How do antihypertensive drugs generally work?
Relaxing and dilating blood vessels or acting on the kidneys to help increase urination
What is considered hypertensive?
140/90
How is blood pressure calculated?
Cardiac output x systematic vascular resistance
What factors do antihypertensive act on?
Blood volume
Contractility
Heart rate
Systemic vascular resistance
How do thiazide diuretics work?
Reducing sodium reabsorption at the distal convoluted tubule
What are the most commonly prescribed diuretics alongside an antihypertensive?
Bendeoflumethiazide
Indapamide
Why do patients on thiazide diuretics need to have potassium levels checked?
Thiazide diuretics aren’t potassium sparing and higher levels of potassium will be excreted
How do loop diuretics work?
They increase sodium excretion in the loop of Henle
What are the most powerful and fastest acting types of diuretics?
Loop diuretics
What are potassium sparing diuretics?
Diuretics which do not waste potassium
How do potassium sparing diuretics work?
By blocking the sodium potassium pumps in the last part of the distal tubule and the start of the collecting duct
What do ACE inhibitors do?
Stop angiotensin 1 turning into angiotensin 2
What patients are given ACE inhibitors?
Patients with:
Hypertension
Heart failure
ACS
Chronic kidney disease
What are ARBs?
Angiotensinogen II receptor blockers
How do calcium channels blockers work?
Inhibition of muscle contraction and nerve transmission
What tissues do Nifedipine and Amlodipine have their main effect on?
Vascular smooth muscle
What tissues does Verapamil have its main effect on?
Conductive tissue
What tissues does Diltiazem have its main effect on?
Coronary vasculature
What do beta blockers inhibit?
Adrenaline and noradrenaline
Are atenolol and bisoprolol selective or non selective beta blockers?
Selective
Are propranolol and labetalol selective or non selective beta blockers?
Non-selective
What are non-selective beta-blockers prescribed for?
Cardiac arrhythmias, anxiety and migraines
What are HMG-CoA reductase inhibitors?
Statins - Drugs that lower cholesterol
How do statins lower cholesterol?
Interrupting the cholesterol synthesis pathway in the liver, inhibiting HMG-CoA reductase, preventing mevalonic acid from forming and activating its pathway which leads to reduced cholesterol synthesis
How do statins affect the levels of LDLs and HDLs in the body?
Reduces LDLs
Increases HDLs (promotes production)
What is the difference between LDLs and HDLs?
LDL cholesterol (“bad” cholesterol) makes up most of your body’s cholesterol. LDLs form plaque and cause atherosclerosis. High levels of LDL cholesterol raise your risk for heart disease and stroke.
HDL cholesterol (“good” cholesterol) absorbs cholesterol in the blood and carries it back to the liver. The liver then flushes it from the body. High levels of HDL cholesterol can lower your risk for heart disease and stroke.
What are the 4 classes of anti-arrhythmic medications?
Class I - Sodium channel blockers
Class II - Beta blockers
Class III - Potassium channel blockers
Class IV - Calcium channel blockers
What are class I anti arrhythmic medications?
Sodium channel blockers (end in -dipine)
What are class I anti-arrhythmic medications used to treat?
Atrial fibrillation and supra-ventricular tachycardias
What are the two most common cardiac specific sodium channel blockers?
Flecainide
Propafenone
What effect at low and high doses does Sotalol have?
At low doses it acts as a beta-blocker and at higher doses it acts as a sodium channel blocker
What are class II anti arrhythmic medications?
Beta blockers (end in -olol)
How do class II anti-arrhythmic medications work?
Blocking the beta receptors in the SA and the AV node -extending the action potential
What are class II anti-arrhythmic medications used to treat?
AF, SVTs, VTs
What are class III anti-arrhythmic medications?
Potassium channel blockers
What do class III anti-arrhythmic medications do?
Prolong the QT
Which patients should not be given class III anti-arrhythmic medications?
Patients with prolonged QTs such as patients with Brugada’s syndrome
Why should you be mindful of potassium channel blocker overdoses?
Patients may take low doses of non-cardiac specific potassium channel blockers for other conditions, usually having no effect on the heart. During an overdose higher levels of these drugs may cause arrhythmias
What are class IV anti-arrhythmic drugs and what are they used to treat?
Calcium channel blockers - primarily SVTs (can also treat VTs but potassium channel blockers shown to be much more effective)
What are the two types of class IV anti-arrhythmic drugs and how do they differ?
Dihydropyridines (DHPs)
e.g. nifedipine and amlodipine
Non-dihydropyridines (Non-DHPs)
e.g. diltiazem and verapamil.
The two classes both help to relax and widen arteries but non-dihydropyridines have an additional effect on the heart’s conduction system and can help to control certain fast heart rhythms (such as atrial fibrillation). This is because non-dihydropyridines also block calcium going into the conducting cells in the heart, which has the effect of slowing down the heart rate.
What are thrombocytes?
Platelets
Where are platelets produced?
The bone marrow
What is the lifespan of platelets?
7-10 days
What do platelets do once activated?
Become ‘sticky’ and release clotting mediators
What are the three parts of haemostasis?
Adhesion
Activation
Aggregation
What stage of haemostasis do anti-platelets usually act on?
Activation
