A nurse is preparing to administer nitroglycerine 15 mcg/min by continuous IV infusion. Available is nitroglycerin 25 mg in 250 mL of dextrose 5% in water (D5W). The nurse should set the IV pump to deliver how many mL/hr? (Round to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.

A) Transdermal patch:
Transdermal patches are designed for slow, continuous delivery of medication through the skin over a long period of time, typically 24 hours. Although they provide steady medication levels, they do not offer a rapid onset of action. This route is more suitable for long-term control of conditions like angina but is not the fastest for immediate relief.

B) Topical ointment:
Topical ointments are applied to the skin and absorb slowly. While they may have local effects, they are not used for quick systemic effects. In the case of nitroglycerin, topical ointments are generally used for sustained release over several hours and are not intended for immediate relief of chest pain.

C) Suspended release:
Suspended release formulations are designed to release the drug slowly over time. Like transdermal patches, these formulations are meant for long-term management, not for rapid onset. A suspended release formulation of nitroglycerin would not provide the immediate relief that is typically needed in cases of acute angina or chest pain.

D) Sublingual:
The sublingual route provides the most rapid onset of action for nitroglycerin. When nitroglycerin is placed under the tongue, it is absorbed directly into the bloodstream through the mucous membranes of the mouth. This bypasses the digestive system and the liver (first-pass metabolism), allowing the drug to take effect quickly—usually within 1 to 3 minutes—making it ideal for acute relief of chest pain or angina. This route is commonly used for emergencies when rapid relief is needed.

Convert the dosage to mcg per hour:

15mcg/min×60min/hr=900mcg/hr15

Convert the available nitroglycerin concentration to mcg/mL:

25mg=25,000mcg

Theconcentrationis(25,000mcg/250mL)=100mcg

Calculate the flow rate in mL per hour using the dosage and concentration:

Flowrate(mL/hr)=(900mcg/hr100mcg/mL)=9mL/hr