Transcript Nitrates/nitrites

Coronary vasodilators
Antianginal drugs
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Angina pectoris: is a clinical syndrome
characterized by paroxysm of pain in the anterior
chest caused by insufficient coronary blood flow
and/or inadequate oxygen supply to the
myocardial muscle.
Causes: (1) Atherosclerosis.
(2) Vasospasim.
There are three groups of drugs used for treatment
of angina:
Nitrates/nitrites.
Beta-adrenergic blocking agents.
Calcium channel blocking agents.
Nitrates/nitrites:
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- Nitrates/nitrites - Action: direct relaxation of
blood vessels and smooth muscles
vasodilatation
O2
requirements.
- Relaxation of smooth muscles of coronary
arteries
coronary vasodilatation
blood supply to the myocardium.
- Relaxation of arteries and veins
BP
workload in the heart.
Objectives of treatment:
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Treatment of anginal attack and thus relief pain.
Prophylactic treatment to prevent or delay the
occurrence of MI.
Prolongs intervals between attacks.
Indications:
Prophylaxis and treatment of acute angina
pectoris.
Treatment of chronic angina pectoris.
Treatment of hypertension associated with MI or
CHF.
Nitroglycerin ointment for treatment of Raynaud’s
disease.
Contraindications:
 Sensitivity
to nitrates
 Hypotension.
 Severe anemia.
 Hypotension.
 Head trauma.
 Cerebral hemorrhage.
Side effects:
 Headache,
syncope, dizziness.
 Postural hypotension, transient flushing,
and palpitation.
 Topical application may lead to
dermatitis.
 Drug interaction: Antihypertensive agents,
Beta-adrenergic blocking agents, and
calcium-channel blocking agents (they
may lead to additive hypotension).
Dosage:
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are several forms available:
 Sublingual: Cordil 5 mg PRN.
 PO: Isotard 20 – 40 mg twice a day.
 Topical: available as patches or
ointment.
 Parental (IV infusion).
Nursing considerations:
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Medications should be taken on an empty stomach.
Carry sublingual tablets in a glass bottle, tightly capped.
If anginal pain is not relieved in 5 minutes by first
sublingual tablet, to take up to 2 more tablets at 5
minutes interval. If pain has not subsided 5 minutes after
the 3rd tablet, client should be taken to the emergency
room as this case could be an infarction (MI) and not
angina.
Take sublingual tablets 5-15 minutes prior to any situation
likely to cause anginal pain such as climbing stairs.
Take sublingual tablets while sitting to avoid postural
hypotension.
Isosorbide dinitrate:
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Present in the forms of capsules; chewable,
sublingual, tablets.
Trade names: Isoral, Cordil, Isotard.
Class: coronary vasodilator.
Dosage forms: caps 20-40 mg, tabs 20-40 mg.
Uses:
Tabs for only prophylaxis of anginal pain.
Chewable, sublingual to terminate acute attack
and relieve acute pain.
Esophageal spasm.
Side effects: Headache, hypotension.
Dosage:
 Sublingual:
acute attack 2.5-5 mg Q 2-3
hrs.
 Oral caps/tabs: 5-20 mg Q 6 hrs.
 Extended release tabs: 20 –80 mg Q 8-12
hrs.
 Note: Isosorbide mononitrate given for
patients with liver impairments.