Key result
A 10-hour nitrate-free interval maintained the 35% improvement in time to 1 mm ST depression with transdermal nitroglycerin, whereas continuous therapy and a 4-hour interval did not.
Why the study?
Does a 10-hour nitrate-free interval prevent tolerance to transdermal nitroglycerin compared to continuous therapy or a 4-hour interval in men with effort angina?
RCT (n=12)
double-blind
randomized
Does a 10-hour nitrate-free interval prevent tolerance to transdermal nitroglycerin compared to continuous therapy or a 4-hour interval in men with effort angina?
Absolute Event Rate: 35% vs 15%
A 10-hour nitrate-free interval, but not a 4-hour interval, effectively prevents tolerance to the anti-anginal efficacy of transdermal nitroglycerin in patients with effort angina.
Supports 10-hour nitrate-free intervals to sustain transdermal nitroglycerin efficacy in effort angina; confirms RCT evidence on optimal dosing to prevent tolerance.
The magnitude of tolerance to the anti-anginal efficacy of transdermal nitroglycerin and the efficacy and safety of short (4 h) and long (10 h) nitrate-free intervals for its prevention, were investigated in a randomized, double-blind, placebo-controlled crossover trial of 4 week-long treatment regimens: placebo, continuous therapy with a 50 mg patch (10 mg.24 h-1), and 4 h and 10 h nitrate-free periods. Only patients showing greater than 1 min increase in time to 1 mm ST depression after acute patch administration were eligible. Twelve men completed the study. One other anti-anginal medication (a beta-blocker in nine and calcium antagonist in two) was permitted in a constant dose throughout the study. Patients underwent exercise testing on days 1 and 7 of each treatment period, and 24 h ambulatory ECG monitoring on day 6. Compared to placebo, transdermal nitroglycerin on day 1 significantly improved time to 1 mm ST depression by 35%, and time to angina, exercise duration and maximal workload by 21%, 13% and 9% respectively. These improvements were totally lost after 7 days' continuous therapy, but completely maintained by a 10 h nitrate-free period (improvements of 35%, 25%, 16% and 11% respectively) but not by a 4 h nitrate-free period (non-significant improvements of 15%, 2%, 4% and 1% respectively). The differences between 10 and 4 h nitrate-free were significant for each end-point. Neither duration of ambulatory ischaemia, nor the proportion of patients experiencing greater than or equal to 5 min ischaemia during the scheduled nitrate-free interval differed between treatments.(ABSTRACT TRUNCATED AT 250 WORDS)
No takes yet. Share an insight, caveat, or question.
Gumbrielle et al. (1992) conducted an RCT in effort angina (n=12). Transdermal nitroglycerin with 10 h nitrate-free interval vs. Continuous therapy, 4 h nitrate-free interval, and placebo was evaluated on Improvement in time to 1 mm ST depression. A 10-hour nitrate-free interval maintained the 35% improvement in time to 1 mm ST depression with transdermal nitroglycerin, whereas continuous therapy and a 4-hour interval did not.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: