Cardiovascular drugs Flashcards
be familiar with the different classes of cardiovascular medications and understand the different mechanisms of action
blood pressure equation
blood pressure = cardiac output x total peripheral resistance
cardiac output equation
cardiac output = heart rate x stroke volume
stroke volume definition
volume of blood being pumped by the left ventricle
total peripheral resistance definition
how much vasoconstriciton vs. vasodilation is present in peripheral circulation
* as peripheral blood vessels constrict, TPR increases
what can you lower to reduce blood pressure?
3
heart rate
stroke volume
total peripheral resistance
how do anti-hypertensives work on different parts of the body?
3
heart: reduce heart rate or comtractability
blood vessels: vasodilation
kidneys: reduce amount of fluid reabsorbed
what is the mechanism of action of ACE-inhibitors? give examples
when BP is low, the Renin-Angiotensin-Aldosterone System (RAAS) increases BP
* renin produced in the kidney nephron converts angiotensinogen in the liver to angiotensin 1
* angiotensin 1 is converted to angiotensin 2 by ACE produced in the lungs and can release aldosterone in the adrenal gland
ACE inhibitors inhibit the release of ACE from the lungs so angiotensin 2 and aldosterone is not produced
* reduced fluid reabsorption in the kidneys
* increased blood volume and blood pressure
ramipril, lisinopril, perindopril
what are the oral impliations of ACE inhibitors?
2
lichenoid tissue reaction
what is the mechanism of action of angiotensin-||-receptor blockers (ARBs)? give examples
when BP is low, the Renin-Angiotensin-Aldosterone System (RAAS) increases BP
* renin produced in the kidney nephron converts angiotensinogen in the liver to angiotensin 1
* angiotensin 1 is converted to angiotensin 2 by ACE produced in the lungs and can release aldosterone in the adrenal gland
ARBs bind to angiotensin 2 receptors on
* smooth muscle of blood vessels to prevent vasocontriction
* coortical walls of adrenal gland to prevent aldosterone production
increased blood pressure
candesartan, losartan, valsartan
what is the mechanism of action of beta blockers? give examples
adrenergic receptors throughout the body:
* alpha 1 - blood vessel smooth muscle
* beta 1 - heart
* beta 2 - smooth muscle in bronchi and bronchioles
* beta blockers can be selective or non-selective for different subtypes of adrenergic receptors
beta blockers competitively inhibit beta 1 receptors on cardiac muscle cells and prevent stimulation by adrenaline
* prevent increase heart rate and contractability
atenolol, bisoprolol, propranolol, carvediol
what are the oral implications for beta blockers?
1
oral lichenoid tissue reaction
what is the mechanism of action of calcium channel blockers? give examples
- inhibit calcium channels on smooth muscle around peripheral blood vessels - reduce vascoconstriction and TPR
- inhibit calcium channels at sino-atrial node - reduce HR
- inhibit calcium channels on cardiac muscle cells - reduce heart contractability
amlodipine, nifedipine, felodipine
what are the oral implications of calcium channel blockers?
gingival enlargement
what is the mechanism of action of diuretics? give examples
work at different parts of the nephron to decrease fluid reabsorption (DCT and CD)
* increased urination = reduced blood volume = reduced blood pressure
furosemide, bendroflumethazide, bumetanide
what are the oral implications of diuretics?
oral lichenoid reactions
dry mouth
what are antiplatelets used for? give examples
coronary heart disease
secondary prevention following MI
peripheral artery disease
secondary prevention following stroke/TIA
aspirin, clopidogrel, ticagrelor, dipyramidole
what is the mechanism of action for aspirin? what are the possible dosages?
inhibits COX-1 enzyme to reduce production of thromboxane A2, reducing platelet aggregation and preventing thrombus formation
* 75mg a day (secondary prevention)
* 300mg (acute MI/stroke)
what is the mechanism of action of dipyramidole?
inhibits phosphodiesterase in platelets
prevents breakdown of cAMP
blocks release of arachidonic acid
what is the mechanism of action for clopidogrel and ticagrelor?
binds to P2Y12 receptors on platelets
prevents ADP binding
stops activation of platelet aggregation
what are the dental implications of anti-platelets?
3
- likely prolonged bleeding time
- pts on DAPT (two anti-platelets) likely to have higher bleeding risk than on one drug
- no need to stop anti-platelet fro dental treatment
what are the two types of anticoagulants? when are they used?
DOCS - used in atril fibrillation
warfarin - used with metallic valve replacement
what are the mechanisms of action of DOACs? give examples
Dabigatran: A selective inhibitor of thrombin (Factor IIa)
Rivaroxaban, apixaban, and edoxaban: Selective inhibitors of activated Factor X (FXa)
what is the mechanism of action of warfarin?
inhibits formation of coagulation factors 2,7,9,10
what are the dental implications of warfarin?
- requires INR monitoring ideally <24 hours before treatment
- if INR <4, can proceed with treatment
- cannot delay or miss dose
- interactions with medications and foods
what are the general principles for anticoagulants?
8
- consult with GP or senior dentist if unsure
- delay dental treatment until anticogulant finishes if planned
- plan treatment for early in the day and week
- “atraumatic” surgery, staged
- consuder packing and suturing
- ensure bleeding has stopped
- give post-operative instructions
- advise pt to take paracetamol, unless contraindicated, for pain relief rather than NSAIDs e.g. aspirin, ibuprofen
what are the advantages of DOACs vs. warfarin?
onset, dosing, food effect, drug interactions, monitoring, offset
what do lipid lowering medications do and what is the name of the medication group?
lower levels of cholesterol
LDL - low density lipoprotein (bad) - contribute to atherosclerosis process
HDL - high density lipoprotein (ok)
statins
what is the mechanism of action of statins? give examples
inhibits enzyme in liver (HMG-CoA reductase) which halts the production of LDL cholesterol
atorvastatin, rosvastatin, simvastatin
what are the dental implications of statins?
interaction with fluconazole, miconazole and clarithromycin to cause rhabdomyolysis (breakdown of muscle)
what is the mechanism of action of anti-anginal medications? give examples
what
angina = narrowing of coronary arteries - chest pain
nitrates relax smooth muscle within coronary vessels, causing vasodilation and improved blood flow
dilates blood vessels returning to heart to reduce preload and reduce work done by heart
GTN spray, isosorbide mononitrate (ISMN), nicorandil
what are the oral implications of anti-anginal medication? how can it be relieved?
nicorandil is a second-line agent in management of angina
can cause severe oral ulceration
heals on withdrawal of medication and relieved with denzydamine mouthwash
