3.7 Cardiac Medications + Dental Side Effects

Question 1

What are the main drug classes used in hypertension medications?

Answer 1

1. ACE inhibitors
2. Angiotensin II anatgonists
3. Calcium channel blockers
4. Thiazide diuretics
5. Beta blockers

Question 2

What are the two types of antianginal medication?

Answer 2

1. Nitrates
2. Aspirin

Question 3

Blood pressure is determined by cardiac output (stroke volume x heart rate) and peripheral vascular resistace. What are the targets for the various hypertension drug classes?

Answer 3

1. Cardiac output (gen) = angiotensin II antagonists
2. Stroke volume specific = diuretics + ACE inhibitors
3. Heart rate specific = beta blockers
4. Vascular resistance = calcium channel blockers

Question 4

How do beta blockers lower heart rate?

Answer 4

Baroreceptor reflex compares arterial pressure to set point

When arterial pressure decreases, signals CNS to increase cardiac output via sympathetic pathway

Beta blockers prevent sympathetic pathway being activated

Question 5

How do ACE inhibitors, angiotensin II antagonists, and diuretics lower heart rate?

Answer 5

Interrupt renin-angiotensin system (RAS) at various points

ACE inhibitors = inhibit angiotensin converting enzyme (ACE)

Angiotensin II antagonists = block angiotensin II (AT) receptors

Diuretics = prevent kidney from H2O + NaCl reabsorption

Question 6

What are examples of ACE inhibitors?

Answer 6

“-prils”

Catopril, Enalapril, Fosinopril, Lisinopril

Question 7

What are the cardio-renal effects of ACE inhibitors?

Answer 7

Vasodilation (arterial + venous) to reduce pressure and ventricular afterload + preload

Decrease blood volume

Inhibit cardiac + vascular hypertrophy

Question 8

What are the side effects of ACE inhibitors?

Answer 8

Electrolyte disbalance

Worsen renal function (if already impaired)

Contraindicated in preganancy (2.7x risk of malformation)

Anaphylaxis

Dry cough

Question 9

What are examples of angiotenin II antagonists?

Answer 9

“-sartans”

Losartan, candesartan, temlisartan

Question 10

Calcium channel blockers block voltage dependent Ca2+ channels to relax vascular smooth muscle cells. What are examples of this type of medication?

Answer 10

Dihydropyridines (-dipine)
Amlodipine, Nifedipine, Felodipine, Nimodipine

Non-nihydropyridines
Diltiszam, verapamil

Question 11

What are the desired effects of calcium channel blockers?

Answer 11

Cardiac = decrease contractility, heart rate, and conduction velocity

Vascular = smooth muscle relaxation

Question 12

What are the side effects of calcium channel blockers?

Answer 12

Vasodilation (ankle oedema, tachycardia, headache, flushing)

Constipation

Verapamil/ciltizem can decrease cardiac output to point of heart failure

Gingiva hyperplasia

Question 13

How do thiazide diuretics work to decrease blood pressure?

Answer 13

1. Inhibit Na+ and Cl- reabsorption in distal tubule, decreasing body water retention + blood volume
2. Direct effect on vascular smooth mucle = less responsive to vasoconstrictors

Question 14

What are potential side effects of thiazide diuretics?

Answer 14

Gout
Hypercalcemia
Hypokalaemia
Hypomagnesemia
Hyperglycaemia
Electrolyte imbalance
Dry mouth

Question 15

Noradrenaline causes both excitatory and inhibitory sympathetics responses due to different membrane receptor proteins. What are these different receptors and their effects?

Answer 15

Alpha-1 = vasoconstriction
Alpha-2 = negative feedback
Beta-1 = Increase heart rate + force of contraction
Beta-2 = relaxes bronchial + vascular smooth muscle

Question 16

What are examples of beta blockers / beta-adrenoreceptor antagonists?

Answer 16

“-lols”

Atenolol, metoprolol, propanolol, pindolol, oxprenolol, sotalol, bisprolol

Question 17

What are the two mechanims behind beta-adrenoreceptor antagonists?

Answer 17

1. Decrease cardiac output by blocking B1 adrenoreceptors in heart
2. Block CNS sympathetic outflow, inhibiting renin release (decreases peripheral resistance)

Question 18

What are th epreferred beta-adrenoreceptor agonists for use, and why?

Answer 18

Cardio selective B1 blockers (atenolol / metoprolol)

Reduction in stroke / MI

Alone = 50-60% effective
With diuretic = 60-80% effective

Question 19

What are possible side effects for beta-adrenoreceptor antagonists?

Answer 19

Bradycardia, reduced exercise capacity, heart failure, hypotension, and AV nodal conduction block

Asthamtic patient = bronchoconstriction

Diabetic patient = Hypotension from masking hypoglycemia

Question 20

What are the common cholesterol lowering medications?

Answer 20

“Statins”

Atorvastatin, fluvastatin, pravastatin, rosuvastatin, simvastatin

Question 21

How do statins lower cholesterol levels and what are the possible side effects?

Answer 21

Inhibits endogenous pathway of cholesterol synthesis

Common complaints = muscle pain

NOT SUITABLE FOR PREGNANT WOMEN

Question 22

How are aspirins and NSAIDs used in patients with heart disease?

Answer 22

1. Prevents arachidonic acid cycle creating COX
2. Small doses block COX 1 = blocks thromboxane + prevent splatelet aggregation / blood clotting

Question 23

What is the difference in effect between 100mg of aspirin and 300mg?

Answer 23

100mg = low dose, recommended for patients with previous cardiac issues eg angina

300mg at chest pain can prevent death + improve heart function immediately after MI

Question 24

Possible side effects of NSAIDs are inducing asthma attacks or actuallay causing cardiovascular disease. What kind of NSAID would cause, rather than prevent cardiovascular disease?

Answer 24

COX 2 specific NSAIDs

COX 2 = anti-inflammatory effects

Question 25

What are nitrates?

Answer 25

Nitrodilators are drugs that mimic the actions of Nitric Oxide (NO) by releasing NO or forming NO within tissues

Question 26

What are the primary cardiovascular actions of nitrodilators (nitrates)?

Answer 26

1. Vasodilation (decrease venous pressure + arterial pressure less so)
2. Cardiac = reduced preload + afterload, decrease O2 demand
3. Coronary = prevents vasospasm, vasodilation, improves subendocardial perfusion, and increase oxygen delivery

Question 27

What are the possible side effects of nitrates?

Answer 27

Headache

Cutaneous flushing

Postural hyptension + reflex tachycardia

Adverse effect on cGMP-dependent phosphodiesterase inhibitors (erectile dysfunction meds)