ALLERGIC REACTIONS TO LOCAL GLYCERYL TRINITRATE ADMINISTRATION

To assess the exact cause and extent of transdermal glyceryl trinitrat e (GTN)-induced allergic reactions, a study of continuous and intermit tent use of GTN patches was conducted in 320 patients with New York He art Association (NYHA) class II and III angina pectoris. Three commerc ially available GTN patch systems were used. Twenty-one patients (6.5% ) developed cutaneous reactions. In 17 patients (5.3%), the reactions were confined to the area of application and were characterised as irr itant reactions. Four patients (1.2%) developed both localised and rem ote from the area of application lesions and one patient developed a g eneralised anaphylactic reaction. The rate of discontinuation of thera py was 3.4%. The irritant skin reactions were mainly due to contaminan ts and additives. Changing to a different transdermal system reduced t he incidence of local reactions - a particularly desirable effect in p atients who respond well to GTN therapy.