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
Beta-blockers exercise implications
• Suppressed heart rate response
• Consider this when setting exercise intensity
targets
• Risk of postural hypotension
Ivabradine - action
• Reduces HR by acting directly on the SA node
• Reduces haemodynamic stress on the heart and so leads to
improvements in angina
• Doesn’t have the side effects of β-blockers (fatigue, sexual
dysfunction, airway constriction)
• Prescribed in angina and heart failure
Ivabradine side effects/exercise implications
• Reduce resting HR by an average of 10bpm
(depending on dose and pre-medication resting HR)
• Improved exercise tolerance (when taken along with β-
blockers) in AF
• Reduces HRmax as much as β-blockers (around
30bpm)
Antihypertensives
ØCalcium channel blockers: inhibit stimulation
of voltage-gated calcium channels leads to increased vasodilation,
decreased peripheral resistance and
cardiac output
-Diltiazem, verapamil
Calcium channel blockers
• Inhibit the entry of calcium into smooth muscle cells
• Results in peripheral vasodilation
• Reduces myocardial contractility (negative inotropic action)
• Some types also reduce heart rate (negative
chronotropic action)
Calcium channel blockers action
-Increase myocardial blood supply through coronary vasodilation -Inhibit smooth muscle contraction to relieve coronary artery spasm -Reduce afterload through arterial vasodilation -Reduce cardiac work Negative inotropic effect Mild negative chronotropic effect
Calcium channel blockers Exercise implications
• Possible reduced heart rate response
(Verapamil & Diltiazem)
• This effect not as pronounced as with betablockers
• Hypotensive response
Antihypertensives
ØAngiotensin-converting enzyme (ACE) inhibitors: decreasedconversion of angiotensin I to II and thus
vasoconstriction and BP; also decreased inflammation
-Enalapril, ramipril, lisinopril
ØAngiotensin receptor blockers (ARBs): block angiotensin II receptors leads to increased vasodilation and decreased BP
-Irbesartan, losartan, valsartan
ACE inhibitors
• ACE inhibitors reduce BP
• Prevent constriction - increase cardiac output, less
myocardial effort
ACE inhibitors used to treat
- Poor LV function
- Heart failure
- Hypertension
ACE inhibitors side effects/exercise implications
• Dry irritating cough • Hypotension • Affects kidney function • Monitor Urea & Electrolytes -Possible increased exercise capacity in heart failure
Antihypercholesterolemics
ØStatins decreased hepatic synthesis of cholesterol and the increased number of LDL receptors on hepatocytes, increases the
elimination of LDL from blood.
-Simvastatin, lovastatin, atorvastatin, rosuvastatin,
pravastatin
Antihypercholesterolemics
ØPCSK9 inhibitors
§ monoclonal antibodies: alirocumab, evolocumab,
bococizumab
§ increases number
and function on LDL receptors in the
liver and increases circulating LDL levels
§ add to the effect of statins
Anti-arrhythmic drugs side effects
Digoxin:- • Nausea, appetite • Vomiting • Fatigue • Slow pulse Amiodarone:- § Metallic taste § Nightmares/glare § Photo sensitivity § Visual disturbances
Anti-arrhythmic drugs exercise implications
• Possible slower heart rate response • Possible reduced exercise capacity • Increased dyspnoea on exertion
