Drugs for Angina Pectoris and Myocardial infarction Flashcards
Nitrates
reduce heart workload
lower oxygen demand
Short acting: terminates acute angina episode
Long acting: decrease severity and frequency of episodes
Adverse effects: hypoTN, dizzy, headache, flush face
prototype: nitroglycerin (Nitrostat)
Nitroglycerin
Therapeutic Class:
Antianginal drug
Pharmacologic Class:
Organic nitrate, vasodilator
Actions and Uses:
Nitroglycerin is most widely used organic nitrate. Delivered — sublingual, PO, intravenous (IV), transmucosal, transdermal, topical, and extended-release PO forms.
It is taken while an acute angina episode is in progress or just prior to
physical activity. When given sublingually, it reaches peak 2 to 4 minutes, terminating angina pain rapidly. Chest pain that
does not respond within 10 to 15 minutes after a single dose of sublingual nitroglycerin may indicate MI, and emergency medical
services (EMS) should be contacted. The transdermal and oral extended release forms are for prophylaxis only because they have a relatively slow onset of action.
Risk/Alerts:
Preg. C
Reduce light exposure
IV bottle and special IV tubing so plastic absorbs nitrate reducing dose
Pharmacokinetics:
Onset- 1-3 min sublingual; 2-5 min buccal; 40-60 min transdermal patch; 15-30 topical ointment
peak- 4-8 min sublingual; 4-10 min buccal; 1-2 hr transdermal patch; 1 hr topical ointment
duration- 30-60 min sublingual; 2hr buccal; 18-24 hr transdermal patch; 7 h topical ointment
Adverse effects:
RARE but nitroglycerin can dilate cerebral
vessels so headache is a common side effect and may be severe. Occasionally, the venous dilation caused by nitroglycerin produces reflex tachycardia. Some healthcare providers prescribe a beta-adrenergic blocker to diminish
this undesirable increase in heart rate. Many of the side effects of nitroglycerin diminish after a few doses.
Contraindications:
No to pts with preexisting hypotension or high cranial pressure or head trauma. Pts with constrictive pericarditis bc heart cannot increase cardiac output to maintain BP when vasodialtion occurs. Pts who have glaucoma because it will increase intraocular pressure
Interactions:
drug to drug–> phosphodiesterase-5 inhibitors that end in (-afil) (erectile dysfunction) may cause life-threatening hypotension and cardiovascular collapse. Use with alcohol and antihypertensive drugs may cause additive hypotension.
lab–> increase values of urinary catecholamines and vanillylmandelic acid concentrations
herbal/food–> hawthorm = hypoTN
overdose–> HypoTN may be reverse with IV NS. For methemoglobinemia you give methylene blue
