Chapter 23: Antianginal Drugs Flashcards
Drugs for angina
Nitrates/nitrites
Beta blockers
Calcium channel blockers
Therapeutic objectives
Minimize the frequency of attacks and decrease the duration and intensity of anginal pain
Improve the pts functional capacity with as few adverse effects as possible
Prevent or delay the worst possible outcome: MI
Nitrates/Nitrites available forms
Sublingual, intravenous solutions, transdermal patches, ointments, translingual sprays (all of these bypass the liver and the first-pass effect)
Oral capsules/tablets, chewable tablets (first-pass effect occurs)
Used to treat acute anginal attacks
Sublingual tablets; intravenous infusion
Rapid-acting forms of nitrates/nitrites
Used to PREVENT anginal episodes
Long-acting forms of nitrates/nitrites
NTG. Prototypical nitrate. Large first-pass effect with oral forms. Sublingual/meter dosed used for treatment of acute chest pain/angina. Used for symptomatic treatment of ischemic heart conditions (angina). IV form used for BP control (vasodilation of venous system) in perioperative hypertension, tx of HF, ischemic pain, pulmonary edema (vasodilation of venous system) associated with acute MI, and hypertensive emergencies (vasodilation of venous system)
Nitroglycerin (Nitro-Bid, Nitrostat). Nitrate.
PO: 5-20 mg BID/TID.
PO: 40-80 mg @0800 and 1300 for sustained release.
Rapid-acting, sublingual tablets, IR tablets and long-acting.
Exerts same effects as other nitrates.
When metabolized in liver, it is broken down into two active metabolites: isosoribide deniitrate and isosoribide mononitrate.
Isosorbide Dinitrate (Isordil)
PO: 20 mg BID given 7 hr apart.
PO: 30-120 mg/day for sustained release
Produce consistent, stead therapeutic response, less variation between pts because it is only one drug
Isosorbide Mononitrate (Imdur)
Adverse effects of nitrates
Headaches: b/c of cerebral arterial dilation. Usually diminish in intensity and frequency with continued use.
Reflex tachycardia (baroreceptors sense decrease in BP, increase HR in response. Short-lived response).
Postural hypotension
Tolerance may develop
Tolerance with nitrates
Occurs in pts taking nitrates around the clock or with long-acting forms. Prevented by allowing a regular nitrate-free period to allow enzyme pathways to replenish. (Transdermal forms: remove patch at bedtime for 8 hours, then apply a new patch in the morning)
Beta blockers
atenolol (Tenormin)
metopropolol (Lopressor)
propanolol (Inderal): passes through the BBB=good for migranes, stage-fright (small doses)
nadolol (Corgard)
Cardio-selective Beta-1 adrenergic blocker (decrease demand, increase supply/perfusion).
PO
Prevent MI in pts with hx
Tx of HTN, angina, thyrotoxicosis
Atenolol (Tenformin)
Cardio-selective Beta-1 adrenergic blockers
PO, IVP
Prophylactic tx of angina
Shown to increase survival in pts experiencing MI
Used for tx of HTN in pts unable to take PO
Contraindicated in pts with asthma/resp disorders
Metopropolol (Lopressor, Toprol XL)
Indications of beta blockers
Angina
Antihypertensive
Cardiac dysrhythmias
Cardioprotective effects, especially after MI
Some used for migrant headaches, essential tremors, and stage fright
Adverse effects of beta blockers
CV: bradycardia, hypotension, atrioventricular block
Metabolic: hyperglycemia and/or hypoglycemia
CNS: dizziness, fatigue, depression, lethargy
Other: impotence, wheezing, dyspnea
Calcium channel blockers
verapamil (Calan, Isoptin) diltiazem (Cardizem) nifedipine (Procardia) amlodipine (Norvasc) nicardipine (Cardene)
High affinity for cardiac conduction system
Effective in the tx of angina pectoris resulting from coronary insufficiency and HTN
One of the few CCB available in parenteral form (used for afib/flitter, PSVT)
Cardizem SR- PO BID
Cardizem CD- PO daily.
Diltiazem (Cardizem). Calcium channel blocker
Indications for CCBs
Angina
HTN
Supraventricular tachycardia
Coronary artery spasms (Prinzmetal angina)
Short-term management of atrial fibrillation and flutter
Adverse effects of CCBs
Limited
Primarily r/t overexpression of their therapeutic effects
May cause hypotension, palpitations, tachycardia or bradycardia, constipation, nausea, dyspnea, other adverse effects
Pts should not take any medications, including OTCs, without checking with their PCP. Pts should be encouraged to limit caffeine intake. Alcohol consumption and spending time in hot baths or whirlpools, hot tubs, or saunas will result in vasodilation, hypotension, and the possibility of fainting.
Teach pts to slowly change positions to avoid postural BP changes.
Encourage pts to keep a record of their anginal attacks, including precipitation factors, number of pills taken, and therapeutic effects.
Nursing implications for anti-anginas drugs
Pts should report
Blurred vision, persistent headache, dry mouth, edema, fainting episodes, weight gain of 2# in one day or 5# in one week, pulse rates less than 60, dyspnea
Instruct pts in proper technique and guidelines for taking sublingual nitroglycerin for anginal pain. Instruct pts never to chew or swallow the sublingual form. Instruct pts that a burning sensation felt with sublingual forms indicates that the drug is still potent. Instruct pts to keep a fresh supply of sublingual medication on hand; potency is lost in about 3 months after the bottle has been opened. To preserve potency, medications should be stored in an airtight, dark glass bottle with a metal cap and no cotton filter.
Nursing implications for sublingual nitroglycerin
Instruct pts in the proper application of nitrate topical ointments and transdermal form, including site rotation and removal of old medication. To reduce tolerance, the pt may be instructed to remove topical forms at bedtime and apply new doses in the morning, allowing for a nitrate-free period.
Topical nitro nursing implications
Instruct pts to take PRN nitrates at the fist hint of anginal pain. Monitor vital sings frequently during acute exacerbations of angina and during IV administration. If experiencing chest pain, the pt taking sublingual nitroglycerin should lie down to prevent or decrease dizziness and fainting that may occur because of hypotension.
More nursing implications for nitroglycerin use
