Nitrates Nitrites

Nitrates/Nitrites

I Available forms:
A. sublingual
B. buccal
C. chewable tables
D. oral capsules/tablets
E. iv
F. ointments
G. transdermal patches
H. translingual sprays (do not shake)
II Mechanism of action
A. cause vasodilation due to relaxation of smooth muscles
B. potent dilating effect on coronary arteries
C. used for prevention and treatment of angina
D. vasodilation results in reduced myocardial O2 demand
E. nitrates cause dilation of both large and small coronary vessels
F. result: O2 to ischemic myocardial tissue
G. nitrates alleviate coronary artery spasms
III Types
A. Nitroglycerin
1. prototypical nitrate
2. large first pass effect w/oral forms
3. Indications
a. used for symptomatic tx of ischemic heart conditions (angina)
b. IV form used for bp control in perioperative hpn, tx of hf, ischemic pain, pulmonary edema assoc w/ acute MI, and HPN emergencies
4. Dosages
a. Nitroglycerin SL (usuallly 0.4 mg) Place one under tongue every 5 minutes x 3 for chest pain. If still pain after 5 min call 911. Should be kept in original container. Once opened replace every 6 months. Side effect of headache should NOT deter use.
5. Nursing implications:
a. take prn nitrates at the first hint of anginal pain
b. the pt taking SL NTG should be lying down to prevent or decrease dizziness and fainting that may occur due to hypotension
c. make sure pts have a nitrate free period of 8-12 hours. Put on patch in am, take off @ night.
d. instruct pts in proper technique/guidelines for SL NTG
e. instruct pts in proper application of ointment and transdermal forms
f. “ “ site rotation & removal of old med daily
g. never chew or swallow the SL form
h. keep a fresh supply of NTG on hand
i. Burning sensation felt w/ SL = drug still potent
j. potency lost after bottle opened for 3 months
k. store in airtight, dark glass bottle w/a metal cap and not cotton filler to preserve potency
l. IV forms of NTG must be contained in glass & given w/infusion pumps
m. discard parenteral soln that is blue, green, or dark red
n. follow specific manuf instructions for Iv admin; use special IV tubing provided or non PVC tubing
B. Nitrates
1. types
a. Isosorbide dinitrate
i. Isordil
ii. Sorbitrate
iii. Dilatrate SR
b. Isosorbide mononitrate
i. Imdur
ii. Monoket
iii. ISMO
2. indications
a. acute relief of angina
b. prophylaxis in situations that may provoke angina
c. long term prophylaxis of angina
3. Side effects
a. headache: usually diminish in intensity and frequency after continued use
b. tachycardia
c. postural hypotension
d. tolerance may develop and need higher doses to be effective