Cardiac: Antianginal Agents

Question 1

Nitroglycerin (Nitrostat)

Onset: 1-3 minutes
Peak effects: 5-10 minutes
Duration: 20-30 minutes
Half-life: 1-4 minutes

MOA: a rapid smooth muscle relaxant that reduces cardiac workload and dilates coronary arteries. Causes vasodilation (decreasing preload), leading to decreased ventricular filling, causing reduced oxygen demand.

Answer 1

Class: Nitrate

Description: a potent smooth muscle relaxer used in the treatment of angina pectoris

Indications: angina pectoris, chest pain associated with MI, acute CHF

Contraindications: hypotension, shock, increased ICP

Precautions: protect from light

Side effects: headache, dizziness, weakness, tachycardia, hypotension, orthostasis, skin rash, dry mouth, N/V

Interactions: can cause severe hypotension in pts who have recently ingested alcohol. Can cause orthostatic hypotension when used with beta-blockers.

Route: SL

Dosage: 0.4 mg every 3-5 minutes, up to 3 doses

Question 2

Nitroglycerin Paste

Onset: 30 minutes
Peak effects: variable
Duration: 3-6 hours
Half-life: 1-4 minutes

Answer 2

Class: Nitrate

Description: Paste contains 2 percent solution. It is absorbed in the circulation, when placed on the skin.

Indications: chest pain, acute MI, CHF

Contraindications: hypotension, shock, increased ICP

Side effects: headache, dizziness, weakness, tachycardia, hypotension, orthostasis, skin rash, dry mouth, N/V

Interactions: same as nitro

Route: topical

Dosage: 1/2 to 1 inch of Nitro-Bid ointment

Question 3

Nitroglycerin Infusion (Tridil)

Onset: immediate
Peak effects: 1-2 minutes
Duration: 3-5 minutes
Half-life: 1-4 minutes

MOA: same as nitroglycerin

Answer 3

Class: Nitrate

Indications: angina, acute CHF, MI

Contraindications: hypotension, shock, increased ICP

Precautions: same as Nitro

Side effects: same as Nitro

Interactions: same as Nitro

Dosage: 5 mcg/min every 3-5 minutes, up to 20 mcg/min. Then, titrate by 10-20 mcg/min