Brand Name
Deponit,
Minitran, Nitro-Bid, Nitrocot, Nitro-Dur, Nitrogard, Nitroglyn E-R, Nitroject,
Nitrol, Nitrolingual, NitroMist, Nitrong SR, Nitro-par, Nitrostat, Nitro-time,
Transderm-Nitro, Tridil
Class and
Category
Chemical
class: Nitrate
Therapeutic
class: Antianginal, antihypertensive, vasodilator
Pregnancy
category: C
Indications
and Dosages
To prevent or treat
angina
E.R.
BUCCAL TABLETS
Adults. 1 mg every
5 hr while awake.
E.R.
CAPSULES
Adults. 2.5, 6.5,
or 9 mg every 12 hr. Frequency of doses increased to every 8 hr based on
patient’s response.
E.R.
TABLETS
Adults. 2.6 or 6.5
mg every 12 hr. Frequency of doses increased to every 8 hr based on patient’s
response.
S.L.
TABLETS
Adults. 0.3 to 0.6
mg, repeated every 5 min. Maximum: 3 tabs in 15 min or 10 mg daily.
TRANSDERMAL
OINTMENT
Adults. 1" to
2" (15 to 30 mg) every 8 hr. Frequency of doses increased to every 6 hr if
angina occurs between doses.Maximum: 5" (75 mg)/application.
TRANSDERMAL
PATCH
Adults. 0.1 to 0.8
mg/hr, worn 12 to 14 hr.
TRANSLINGUAL
SPRAY
Adults. For
treatment, 1 or 2 metered doses (0.4 or 0.8 mg) onto or under tongue, repeated
every 5 min as needed. For prevention, 1 or 2 metered doses (0.4 or 0.8 mg)
onto or under tongue 5 to 10 minutes before activities that could lead to acute
attack.
To prevent or treat
angina, to manage hypertension or heart failure
I.V.
INFUSION
Adults. 5 mcg/min,
increased by 5 mcg/min every 3 to 5 min to 20 mcg/min, as prescribed, and then
by 10 to 20 mcg/min every 3 to 5 min until desired effect occurs.
Mechanism
of Action
May interact with nitrate
receptors in vascular smooth-muscle cell membranes. This interaction reduces
nitroglycerin to nitric oxide, which activates the enzyme guanylate cyclase,
increasing intracellular formation of cGMP. Increased cGMP level may relax vascular smooth muscle by forcing calcium out of muscle cells, causing vasodilation.
Venous dilation decreases venous return
to the heart, reducing left ventricular enddiastolic pressure and pulmonary
artery wedge pressure. Arterial dilation decreases systemic vascular
resistance, systolic arterial pressure, and mean arterial pressure. Thus, nitroglycerin
reduces preload and afterload, decreasing myocardial workload and oxygen demand.
It also dilates coronary arteries, increasing blood flow to ischemic myocardial
tissue.
Route Onset Peak Duration
P.O. 3 min Unknown 5 hr
P.O. 20–45 min Unknown 8–12 hr
I.V. 1–2 min Unknown 3–5 min
S.L. 1–3 min Unknown 30–60 min
Trans- In 30 min Unknown 4–8 hr dermal‡
Trans- In 30 min Unknown 8–24 hr dermal§
Trans- 2 to 4 min Unknown 30–60 min lingual
Incompatibilities
Don’t administer I.V. nitroglycerin
through I.V. bags or tubing made of polyvinyl chloride. Don’t mix drug with
other solutions.
Contraindications
Acute MI (S.L.), angle-closure
glaucoma, cerebral hemorrhage, concurrent use of phosphodiesterase inhibitors,
constrictive pericarditis (I.V.), head trauma, hypersensitivity to adhesive in
transdermal form, hypersensitivity to nitrates, hypotension (I.V.), hypovolemia
(I.V.), inadequate cerebral circulation (I.V.), increased intracranial pressure,
orthostatic hypotension, pericardial tamponade, severe anemia
Interactions
DRUGS
acetylcholine,
norepinephrine: Possibly
decreased therapeutic effects of these drugs
heparin: Possibly decreased
anticoagulant effect of heparin (I.V. nitroglycerin)
opioid analgesics,
other antihypertensives, vasodilators: Possibly increased orthostatic hypotension
phosphodiesterase
inhibitors, such as sildenafil: Possibly severe hypotensive effect of nitroglycerin
sympathomimetics: Possibly decreased
antianginal effect of nitroglycerin and increased risk of hypotension
ACTIVITIES
alcohol use: Possibly increased
orthostatic hypotension
Adverse Reactions
CNS: Agitation, anxiety,
dizziness, headache, insomnia, restlessness, syncope, weakness
CV: Arrhythmias (including
tachycardia), edema, hypotension, orthostatic hypotension, palpitations
EENT: Blurred vision,
burning or tingling in mouth (buccal, S.L. forms), dry mouth
GI: Abdominal pain, diarrhea,
indigestion, nausea, vomiting
GU: Dysuria, impotence,
urinary frequency
HEME: Methemoglobinemia
MS: Arthralgia
RESP: Bronchitis, pneumonia
SKIN: Contact dermatitis
(transdermal forms), flushing of face and neck, rash
Nursing Considerations
• Use nitroglycerin cautiously in
elderly patients, especially those who are volume depleted or taking several
medications, because of the increased risk of hypotension and falls.
Hypotension may be accompanied by angina and paradoxical slowing of the heart
rate. Notify prescriber if these occur, and provide appropriate treatment, as
ordered.
• Plan a nitroglycerin-free period of
about 10 hours each day, as prescribed, to maintain therapeutic effects and
avoid tolerance.
• Place E.R. buccal tablets in buccal
pouch with patient in sitting or lying position.
• Don’t break or crush E.R. tablets or
capsules. Have patient swallow them whole with a full glass of water.
• Place S.L. tablet under patient’s
tongue and make sure it dissolves completely.
• Be sure to remove cotton from S.L.
tablet container to allow quick access to drug.
When applying transdermal
ointment, apply correct amount on dose-measuring paper. Then place paper on
hairless area of body and spread in a thin, even layer over an area at least 2
inches by 3 inches. Don’t place on cuts or irritated areas.Wash your hands
after application. Rotate sites. Store at room temperature.
•Open transdermal patch
package immediately before use. Apply patch to hairless area, and press edges
to seal. Rotate sites. Store at room temperature. If patient needs
cardioversion or defibrillation, remove transdermal patch.
• Don’t shake translingual
spray container before administering. Have patient inhale and hold her breath,
and then spray drug under or on her tongue.
• Be aware that I.V.
nitroglycerin should be diluted only in D5W or normal saline solution and
shouldn’t be mixed with other infusions. The pharmacist should add drug to a
glass bottle, not a container made of polyvinyl chloride. Don’t use a filter
because plastic absorbs drug. Administer with infusion pump.
• Check vital signs before
every dosage adjustment and often during therapy.
• Frequently monitor heart
and breath sounds, level of consciousness, fluid intake and output, and
pulmonary artery wedge pressure, if possible.
• Store premixed containers
in the dark; don’t freeze them.
WARNING Assess
patient for evidence of overdose, such as confusion, diaphoresis, dyspnea,
flushing, headache, hypotension, nausea, palpitations, tachycardia, vertigo, vision
changes, and vomiting. Treat as prescribed by removing nitroglycerin source, if
possible; elevating legs above heart level; and administering an
alpha-adrenergic agonist, such as phenylephrine, as prescribed, to treat severe
hypotension.
PATIENT
TEACHING
• Teach patient to
recognize signs and symptoms of angina pectoris, including chest fullness,
pain, and pressure, possibly with sweating and nausea. Pain may radiate down
left arm or into neck or jaw. Inform women and those with diabetes mellitus or
hypertension that they may feel only fatigue and shortness of breath.
• Instruct patient to read
and follow package instructions to obtain full benefits of drug.
• To prevent drug
tolerance, inform patient that prescriber may order a 10- to 12-hour drug-free
period at night (or at another time if she has chest pain at night or in the morning).
• Instruct patient to
swallow E.R. tablets or capsules whole—not to break, crush, or chew them—with a
full glass of water.
• For sublingual or buccal
use, advise patient to place tablet under her tongue or in buccal pouch when
angina starts and then to sit or lie down. Instruct her not to swallow drug,
but to let it dissolve. Explain that moisture in her mouth helps drug absorption.
If angina doesn’t subside, instruct patient to place another tablet under her
tongue or in buccal pouch after 5 minutes and to repeat, if needed, for three
doses total. If pain doesn’t subside after 20 minutes, urge patient to call 911
or another emergency service.
• Advise patient to carry
S.L. tablets in their original brown bottle in a purse or jacket pocket, but
not one that will be affected by body heat. Instruct her to store drug in a dry
place at room temperature and to discard cotton from container. Advise her to discard
and replace S.L. tablets after 6 months.
• Advise patient using
transdermal ointment or patch to rotate sites to avoid skin sensitization.
• Inform patient that
swimming or bathing doesn’t affect transdermal forms but that hot tubs, saunas,
prolonged hot showers, electric blankets, and magnetic therapy over the site
may increase drug absorption and cause dizziness and hypotension.
• Caution against inhaling
translingual spray. Before first use, tell patient to press actuator button 10
times to prime container and then hold container upright with forefinger on top
of actuator button. Tell her to open her mouth, bring container as close as
possible, press actuator button firmly to release spray onto or under tongue,
and release button and immediately close her mouth. Remind her to replace
plastic cover on container and to not spit out the drug or rinse her mouth for
5 to 10 minutes. Tell her to reprime container by pressing actuator button twice if container
hasn’t been used for more than 6 weeks. Remind
patient to periodically check level of fluid
in container. If it reaches the top or middle
hole on side of container, more should be obtained. Caution patient not to let level of liquid get to bottom of hole.
• Inform patient that nitroglycerin
commonly causes headache, which typically resolves after a few days of
continuous therapy. Suggest taking acetaminophen, as needed.
• Advise patient to notify prescriber
immediately about blurred vision, dizziness, and severe headache.
• Suggest that patient change positions
slowly to minimize orthostatic hypotension.
• Advise patient to avoid hazardous
activities until drug’s CNS effects are known.
• Urge patient to avoid alcohol and
erectile dysfunction drugs during therapy.
