Transdermal nitroglycerin systems: methods for comparison
Harrison, L.I.; Riedel, D.J.
Clinical Therapeutics 13(3): 361-367
1991
ISSN/ISBN: 0149-2918 PMID: 1954637 Document Number: 385551
A number of transdermal nitroglycerin delivery systems are able to maintain a constant plasma level of nitroglycerin for up to 24 hours, even though the drug's elimination half-life is only a few minutes. Unfortunately, wide variations in plasma drug levels reported in studies of transdermal delivery systems can make plasma level comparisons between products inappropriate and misleading. Other measures of clinical performance include adhesive properties and patient preference. In one adhesion study, Minitran demonstrated superior adhesive properties when compared with Transderm-Nitro, Nitro-Dur II, and a medical reference tape. In patient preference studies involving several hundred patients with angina pectoris, patients consistently selected Minitran over Transderm-Nitro or Nitro-Dur II, citing patch size, shape, ease of application, comfort, better patch adhesion, and reduced instances of skin irritation. It has now been established that a daily nitrate-free interval of eight to 12 hours is required to prevent nitrate tolerance in most patients. With the proper patch application interval, transdermal nitroglycerin remains as important therapeutic option in the treatment of angina pectoris and silent myocardial ischemia. In the present article, we compare three transdermal nitroglycerin patches, using both published2-8 and new studies. The methods used to compare the products will be discussed.