Pharmacotherapy Flashcards
What are the 4 aims of pharmacotherapy?
Dilation of coronary arteries ↓ Improves coronary supply
Arterial vasodilation ↓ Reduces arterial resistance ↓ Reduces afterload
Venodilation ↓ Reduces venous return ↓ Reduces preload
Decreases sympathetic drive ↓ Reduces heart rate and contractile force ↓ Reduces cardiac work
Oral platelet inhibitors
ØAspirin and clopidogrel interfere with platelet activation and/or
aggregation.
ØTicagrelor is a new medication which inhibits platelet aggregation and
thrombus formation in atherosclerotic disease. NICE suggests it is
prescribed along with aspirin for a year following an ACS
Anticoagulants
ØWarfarin and heparin interfere with the coagulation cascade.
ØNew drugs available with less of the unwanted side-effects and issues
warfarin has – termed Novel Oral Anti-Coagulants (NOACs) – e.g.
rivaroxaban
Anticoagulants and platelets side effects
Aspirin/Clopidogrel • Small doses - less risk of gastric bleeding Ticagrelor • Risk of fatal bleeding • Dyspnoea Warfarin • Overdose thins blood - bleeding • Regular blood tests necessary to check blood ‘thinness’ • No aspirin, limit alcohol • Be aware of potential accidents • Caution with equipment
Antianginals
ØNitroglycerin increase vasodilation and blood flow
ØLong-acting, e.g. isosorbide mononitrate
ØFast-acting GTN (glyceryl tri-nitrate) – sub-lingual spray or tablets; fast
access to the blood-stream through the buccal mucosa
Types of nitrates
Long Acting and Short Acting
Long Acting • control & prevent angina • improve heart failure • Oral - modified release tablets, or • Transdermal – cream or patches Short Acting • used for break-through pain • act within minutes • Sublingual - dissolve under tongue (tablets) • Spray under tongue
How nitrates work in Angina?
-Reduce preload through venodilation -Improve myocardial perfusion -Reduce afterload by lowering arterial resistance -Effect comes from conversion to nitric oxide, mimicking the effects of endothelial NO
Nitrates Exercise Implications
- Postural hypotension
- Caution with ß-blockers
- BP drops after GTN - rest for 5 minutes
- Increases ischaemic threshold
Use of GTN
• Let person use own tablets or spray
• Must inform you when taking
• Do not lie them down
• If no effect repeat once more after 5 minutes (total of 2
doses). If no relief dial 999!
• If relieved - rest 5 mins & resume exercise if client wishes
• Can use prior to exercise to prevent angina
Antihypertensives
ØDiuretics: increased rate
of urine excretion and decreased plasma volume leads to decreased BP
-Furosemide, thiazides, amiloride, spironolactone
Diuretics
- Act on kidneys which govern water content of body
- Increase volume of urine excreted by removing salt and water
- Sodium chloride takes water with it
- Less circulating fluid reduces BP
- Reduced myocardial work helps heart failure
Diuretics used to treat?
• Hypertension
• Poor LV
function
• Heart failure
Diuretics Exercise Implications
• Dehydration - encourage
fluids in hot weather
• Access to toilets
• Aching legs
Antihypertensives
Øβ-blockers: bind to β-adrenergic receptors, inhibiting the action of
catecholamines -> decrease HR, BP, myocardial O2 demand
§ Atenolol, propranolol, metoprolol, bisoprolol
• HR lowering/anti-anginal - ivabradine
How do Beta-Blockers work in angina?
-Reduce afterload by lowering arterial resistance (BP)
-Increase coronary perfusion by increasing diastole due to the
negative chronotropic response
-Reduce cardiac work
through the negative
chronotropic and
inotropic effects
