ANTIANGINAL AGENTS
INTRODUCTION
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THREE MAIN CORONARY ARTERIES
– 1 RIGHT CORONARY, 2 LEFT CORONARY ARTERIES
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RECEIVE 4% OF ALL BLOOD FLOW
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CAPTURES 10% OF ALL OXYGEN
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CARDIAC MUSCLE HAS LIMITED
CAPACITY FOR ANAEROBIC METABOLISM
ANGINA
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IMBALANCE BETWEEN MYOCARDIAL
OXYGEN REQUIREMENT VERSUS DELIVERY
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CAUSES ACUTE REVERSIBLE LEFT
VENTRICULAR FAILURE AND PAIN
ANGINA ETIOLOGY
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ATHEROSCLEROSIS
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VASOSPASM (PRINZMETAL)
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HYPERTENSION
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ANEMIA
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THYROTOXICOSIS
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CONGESTIVE HEART FAILURE
ANGINAL PRECIPITATING FACTORS
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OVEREATING
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EXERCISE
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INTENSE EMOTIONAL STIMULI
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EXTREMES OF HEAT AND COLD
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MEDICATION: sympathomimetics, anorectic agents,
antidepressants
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SMOKING
THERAPEUTIC ALTERNATIVES
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INVASIVE
– surgery, angioplasty
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PHARMACOLOGIC
– Decrease cardiac workload
– Reverse vasospasms
– Does not treat underlying pathology
NITRATES
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CORONARY ARTERY VASODILATION
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PERIPHERAL ARTERY DILATION
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PERIPHERAL VENOUS DILATION
– Decreases pre-load (primary mechanism)
• increases venous pooling, decreasing return to heart
• decreases amount of blood to pump
• decreases work load
• decreases oxygen demand
NITRATE USES
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ACUTE ANGINA - relief of symptom
of pain
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PROPHYLACTIC - decreasing
incidence of anginal pain by administering medication routinely.
– Or administer prior to exertion
NITRATE CAUTION
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TOLERANCE DEVELOPS TO CONSTANT
BLOOD LEVELS
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INCREASES INTRA OCULAR PRESSURE
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SIDE EFFECTS
– Headache
– Syncope
– Cutaneous flushing
NITRATE COMPARISON
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ACUTE ONSET DURATION
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NTG
SUBLINGUAL 3 MIN 10 MIN
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ISDN
DINITRATE 2-5 MIN 1 HR
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PROPHYLACTIC
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NTG
Ointment 1 HR 4-6 HRS
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ISOSORBIDE
TAB 1/2 HR 6 HRS
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NTG
PATCH 24 HR 24 HR
NITRATE SUBLINGUAL
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Use lowest dose
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Administer as tablet or spray
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1 dose every 5 minutes for 3 doses
maximum
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Tablets leave a burning sensation
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Store in glass bottle with metal
cap
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Store in cool non-humid place
NITRATE OINTMENT
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Dosed by the inch
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Remove previous application
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Placed on skin surface with good
blood supply
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Use gloves when applying
– To avoid tolerance and
hypotension
NITRATE PATCH
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24 hour onset
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To prevent tolerance remove at
bedtime
NITRATE INJECTION
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USE
– Unstable Angina
– Post-cardiac surgery
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ADMINISTER UTILIZING NON-PHTHALATE
INJECTION TUBING
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Decreases pre-load and after-load
BETA BLOCKERS
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Pharmacology
– Decrease heart rate
– Decreases cardiac work load
– Decreases cardiac oxygen demand
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Low dose administration
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Abrupt withdrawal exacerbates
cardiac ischemia
CALCIUM CHANNEL BLOCKERS
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USE
– CLASSICAL ANGINA - decreases cardiac work load
– VASOSPASM ANGINA - increases oxygen supply by dilating coronary
arteries