title: A randomized, double-blind, placebo-controlled, crossover study to assess the immediate effect of sublingual glyceryl trinitrate on the ankle brachial pressure index, claudication, and maximum walking distance of patients with intermittent claudication.
abstract: OBJECTIVE
  The goal of the present study was to assess the immediate effect of sublingual glyceryl trinitrate (GTN) in patients with intermittent claudication.
  
  
  METHODS
  We conducted a randomized, double-blind, placebo-controlled crossover study. Inclusion criteria consisted of history of intermittent claudication, resting ankle brachial pressure index (ABPI) of 1.00 or less, a 20% or greater fall in ABPI after exercise, and maximum walking distance (MWD) of less than 250 m. Patients already receiving nitrates were excluded. In study 1, patients (n = 25) underwent a standard exercise test after randomization to receive either 800 microg of sublingual GTN or placebo. The postexercise ABPI was recorded. Then, the crossover portion of the study was performed. In study 2, patients (n = 22) had their claudication distance and MWD measured. They then were randomized to receive either GTN or placebo spray, and the exercise test was repeated, with the claudication distance and MWD recorded, followed by the crossover portion of the study. Statistical analysis was performed with the Wilcoxon matched pairs signed ranks test and the Mann-Whitney U test.
  
  
  RESULTS
  In study 1, the median postexercise ABPIs for placebo and GTN were 0.29 and 0.36 (P =.0001). In study 2, the median claudication distance for both placebo and GTN groups was 70 m (P =.59). The median MWD for the placebo and GTN groups was 105 and 125 m (P =.0084)
  
  
  CONCLUSIONS
  GTN can decrease the fall in ABPI after exercise and increase the MWD.
authors.affiliation: Department of Vascular and Endovascular Surgery, Queens Medical Centre,Nottingham, UK.
authors.forename: S R
authors.initials: SR
authors.lastname: Walker
authors.forename: S
authors.initials: S
authors.lastname: Tennant
authors.forename: S T
authors.initials: ST
authors.lastname: MacSweeney
mesh_terms: D000286:Administration, Sublingual; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005080:Exercise Test; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D016138:Walking
chemical_list: D014665:Vasodilator Agents; D005996:Nitroglycerin