Local effect of transdermal isosorbide dinitrate ointment on hand vein diameter

Area of Science:

• Pharmacology
• Vascular Biology

Background:

• Superficial hand veins can be challenging for venepuncture.
• Topical vasodilators may improve venous access.

Purpose of the Study:

• To evaluate the efficacy of topical isosorbide dinitrate (ISDN) ointment in dilating preconstricted superficial hand veins.

Main Methods:

• A double-blind, randomized, placebo-controlled crossover trial was conducted in 12 healthy volunteers.
• Hand vein compliance technique measured venous diameter changes after phenylephrine preconstriction and ISDN or placebo ointment application.
• Nitroglycerine was administered intravenously to determine maximal venous response.

Main Results:

• ISDN ointment significantly dilated hand veins by 39.1% (P=0.02), peaking around 42.5 minutes.
• The dilator effect was inversely correlated with baseline venous diameter (r²=0.38, P=0.03).
• Effect was independent of ISDN dose or preconstriction level (P > 0.3).

Conclusions:

• Topical ISDN can relax superficial hand veins, potentially facilitating venepuncture, especially in small vessels.
• Significant variability in effect and onset time currently limits its clinical utility.