title: Transdermal nitroglycerin: clinical and pharmacokinetic consequences of renewing the patch and the application site.
abstract: OBJECTIVE
  We examined whether nitroglycerin (glyceryl trinitrate, GTN) patch treatment for 24 h could induce local cutaneous changes that impaired drug delivery and clinical efficacy.
  
  
  METHODS
  Twenty angina patients 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 location or on the previous application site in a randomised, double-blind, cross-over protocol. GTN plasma concentrations and finger plethysmography were obtained before and after each exercise test.
  
  
  CONCLUSIONS
  The clinical efficacy, the effect seen on plethysmography and the GTN plasma concentrations tended to increase after patch renewal, regardless of the application site of the renewed patch. Hence, cutaneous changes of clinical importance could not be demonstrated.
authors.affiliation: Department of Cardiology, Ullevål University Hospital, Oslo, Norway.
authors.forename: T O
authors.initials: TO
authors.lastname: Klemsdal
authors.forename: H H
authors.initials: HH
authors.lastname: Mundal
authors.forename: J E
authors.initials: JE
authors.lastname: Bredesen
authors.forename: K
authors.initials: K
authors.lastname: Gjesdal
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D001682:Biological Availability; D018592:Cross-Over Studies; D005080:Exercise Test; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D017156:Photoplethysmography; D013997:Time Factors; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use
chemical_list: D014665:Vasodilator Agents; D005996:Nitroglycerin