TRANSDERMAL NITROGLYCERIN - CLINICAL AND PHARMACOKINETIC CONSEQUENCESOF RENEWING THE PATCH AND THE APPLICATION SITE

Objective: We examined whether nitroglycerin (glyceryl trinitrate, GTN ) patch treatment for 24 h could induce local cutaneous changes that i mpaired drug delivery and clinical efficacy. Methods: Twenty angina pa tients were exercise-tested after 2 and 24 h of treatment and then 2 h after patch renewal. The patch was either renewed on a new skin locat ion or on the previous application site in a randomised, double-blind, cross-over protocol. GTN plasma concentrations and finger plethysmogr aphy were obtained before and after each exercise test. Results and co nclusions: The clinical efficacy, the effect seen on plethysmography a nd the GTN plasma concentrations tended to increase after patch renewa l, regardless of the application site of the renewed patch. Hence, cut aneous changes of clinical importance could not be demonstrated.