Nitroglycerin

Question 1

What is the generic name for Nitrostat?

Answer 1

Nitroglycerin

Question 2

Trade name for nitroglycerin?

Answer 2

Nitrostat, nitro-bid, tridil

Question 3

Classification of nitroglycerin?

Answer 3

nitrate, anti-anginal, vasodilator

Question 4

How is nitroglycerin supplied?

Answer 4

0.3 mg tabs SL, 0.4 mg/spray, 50 mg/10 ml vial or (premixed IV bag 100 mcg/mL, 200 mcg/ml)

Question 5

Pharmacodynamics of nitroglycerin

Answer 5

❑ Antianginal: relaxes vascular smooth muscle of both venous and arterial beds, resulting in a net decrease in the myocardial oxygen consumption. It also dilates coronary vessels, leading to redistribution of blood flow to ischemic tissue and improves collateral circulation.
❑ Vasodilating: dilates peripheral vessels, decreasing venous return to the heart (preload) useful in treating pulmonary edema and heart failure. Arterial vasodilation decreases afterload, thereby decreasing left ventricular work and
aiding the failing heart.

Question 6

Indications (4 points) for nitroglycerin

Answer 6

❑ Initial antianginal for suspected ischemic chest pain
❑ For initial 24 – 48 hours in patient with AMI and CHF, large interior wall infarction, persistent or recurrent ischemia
❑ Continued use (beyond 48 hours) for patients with recurrent angina or persistent pulmonary congestion
❑ Hypertensive emergencies; Non-cyclic antidepressant overdose; stimulant overdose (Use IV infusion ONLY; no bolus required)

Question 7

nitroglycerin dosage

Answer 7

SL - 0.3 mg tab or 0.4 mg spray q 5 min prn; max of 3 doses AHS q 5 min prn or until systolic BP less than 100 mmHg

IV - AHS 15mg/250ml (60mcg/mL) IV/IO start at 20 mcg/min, increase by 10 mcg/min q 5 minutes prn to a maximum of 200 mcg/min
Portage: Bolus 30 – 60 mcg (if no SL medication given); begin infusion at 10 mcg/min; titrate to effect; increase by 10 mcg/min q 3-5 min. Max dose of 200 mcg/min; Mix 25 mg/250 ml NS or D5W (100 mcg/ml)

Transdermal Patch – 0.2 – 0.8 mg/hr

Pediatric
0.5-1.0 mcg/kg/min IV/IO to a max of 10mcg/kg/min.

Question 8

Contraindications for nitroglycerin

Answer 8

❑ Right ventricular infarction (Sublingual Spray Administration- 0.3mg to 0.4 mg are too large a dose and will drop preload and significantly decrease cardiac output. This increases mortality rates in these patients)
❑ Hypersensitivity to nitrates
❑ Avoid use in extreme bradycardia (<50 bpm)
❑ Hypotension (<90 mmHg) or a drop of >30 mmHg below baseline (systolic BP)
❑ Uncorrected hypovolemia
❑ sildenafil (Viagra), vardenafil (Levitra) use within 24 hours or tadalafil (Cialis) within 48 hours

Question 9

Precautions for nitroglycerin

Answer 9

❑ Orthostatic hypotension may occur – consider administering while patient recumbent or after placing on stretcher.
❑ With evidence of AMI and norm-tension, do not reduce SBP to <110mmHG. If pt. is hypertensive, do not decrease MAP by >25% from initial MAP

Question 10

Notable notes to note - nitroglycerin

Answer 10

❑ Do not shake aerosol spray because this affects metered dose
❑ An IV must be initiated prior to the administration of nitroglycerin.
❑ Remove other nitro sources (e.g. Nitro patch before administering SL or IV nitro).
❑ Use glass bottles and special tubing provided by the manufacturer for infusion.
❑ Single most effective agent for the treatment of acute pulmonary edema

Question 11

Kinetics (onset, peak, duration) - nitroglycerin

Answer 11

SL:
Onset: 1-3 mins
Peak: unknown
Duration: 30-60 mins

Patch:
Onset: 40-60 mins
Peak: unknown
Duration 8-24 hrs

IV:
Onset: immediate
Peak: unknown
Duration: several mins

(Davis Drug Guide 16th ed.)