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Nitroglycerin Dose Conversions for Nitro Paste vs. IV Infusion

Summary:

While nitroglycerin paste (or ointment; i.e., "nitropaste") offers less control and ability to titrate to specific effects, it can be a useful route of administration when drug shortages exists with other dosage forms and/or when transitioning patients to other services. 

  • If switching a patient from IV infusion to ointment, apply the ointment and then 30 minutes later stop the IV infusion. 
  • If going from the ointment to an IV infusion the duration of nitroglycerin ointment can stick around a lot longer (up to ~12 hrs) and be less predictable, so approximately one hour after the ointment has been removed, start the IV infusion at the equivalent lower end of the range and adjust as needed.  

Estimated Dose Conversions:

  • 0.5" of paste = 5 mcg/min IV infusion
  • 1.0" of paste = 10 - 39 mcg/min IV infusion
  • 1.5" of paste = 40 - 59 mcg/min IV infusion
  • 2.0" of paste = 60 - 100 mcg/min IV infusion


Editor-in-Chief:  Anthony J. Busti, MD, PharmD, FNLA, FAHA
Peer-Reviewer:  Dylan Kellogg, MD
Last Reviewed:  Augus 2015

Original Study

  • Esposito GA, et al. Converting IV nitroglycerin therapy to nitroglycerin ointment therapy: a comparison of two methods. Am J Crit Care 1998;7(2):123-30. PubMed
    Study Design Prospective, Randomized, Single-Center
    Sample Size n = 200 patients in the ICU receiving IV nitroglycerin at doses of 10 to 100 mcg/min
    Objective The time patients remained in the ICU after the conversion from one form of nitroglycerin to another.
    Treatment Groups
    • Group 1 = Apply nitroglycerin ointment and stop IV nitroglycerin 30 min later
    • Group 2 = Decrease the dose of IV nitroglycerin by 10 mcg/min every 15 min, apply one half the dose of nitroglycerin ointment when the original IV dose has been decreased by one half, and apply the full dose of the ointment when the IV nitroglycerin is stopped
    • Conversions used:  0.5" of paste = 5 mcg/min IV infusion; 1.0" of paste = 10 - 39 mcg/min IV infusion; 1.5" of paste = 40 - 59 mcg/min IV infusion; 2.0" of paste = 60 - 100 mcg/min IV infusion
    Results
    • The application of nitroglycerin ointment and then stopping the IV nitro infusion 30 min later resulted in a reduced median time before transfer from the ICU by 23 minutes and median nursing time by 45 minutes.
    • Analysis of all clinical outcomes showed no differences between the two methods.
    Conclusions Group 1 patients had reduced time in the ICU before transfer to another unit and there were no differences in outcomes.
    Comments While this study was not designed to determine dose equivalency it demonstrated that the method of dosge conversions appears to confer the same clinical effects and is the better data available.
    Location Duke Medical Center, Durham, NC

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