Nitrate Therapy

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Nitrates

• called vasodilators

• primarily used to treat angina pectoris, hypertension, and heart failure

• most common kinds are:

  • nitroglycerin

  • isosorbide dinitrate

  • isosorbide mononitrate

Nitroglycerin

lipid soluble and easily absorbed through cellular membranes

• can be given many ways:

  • sublingual (under tongue) or oral spray to treat acute anginal pain or hypertension

  • transdermal patches or topical ointments for long-term prevention

  • rectally for the treatment of anal fissures

How nitroglycerin works

• quickly converted into nitric oxide once absorbed into blood

  • nitric oxide diffuses into the smooth muscle cells of both veins and arteries, causing vasodilation

    • result of venous vasodilation is peripheral blood pooling, which decreases preload, or the pressure that stretches the heart as it fills with blood from venous return

    • result of arterial vasodilation lowers the systemic vascular resistance, which will also reduce the afterload, or the pressure that the heart must work against to eject blood during ventricular contraction

• dilates the coronary arteries, increasing the blood supply to cardiac muscle

Side effects of nitroglycerin

• headache

• dizziness

• flushing

• peripheral edema

• orthostatic hypotension

• lightheadedness or syncope

• reflex tachycardia

• prolonged use can develop tolerance to side effects and therapeutic effects

Contraindications of Nitroglycerin

• during right ventricular myocardial infarction

• hypotension

• shock

• cardiac tamponade

should not be used in patients with:

• severe anemia

• cardiomyopathy

• increased intracranial pressure

• cerebral hemorrhage

Interactions with nitroglycerin

should never be combined with:

• other substances that cause vasodilation, such as alcoholic beverages

• medications used to treat erectile dysfunction

Nursing considerations

• complete a baseline assessment with vital signs and medications that could interact with nitroglycerin

• check lab reports, including CBC, hepatic and renal function, and lipid profile

• wear gloves when handling the medication, since it can be absorbed through the skin very quickly

• monitor patient for side effects

• evaluate the effectiveness of nitrate therapy

Patient education

• teach safe self-administration

• explain why their med is prescribed and how to administer it

• medication is sensitive to light, moisture, and heat; so advise them to store their nitroglycerin pills in their original container at room temperature and always carry some around

• For patients who experience angina with activity, remind them to take their nitroglycerin prior to precipitating activities, like playing sports or mowing the lawn

• if taking for acute angina, call 911 if pain does not resolve within 5 minutes of taking the first dose

  • while waiting, may take 2nd and 3rd nose 5 minutes apart