Transdermal nitroglycerin is indicated for the prevention of angina pectoris due to coronary artery disease.The onset of action of transdermal nitroglycerin is not sufficiently rapid for this product to be useful in aborting an acute attack.
Use of Nitroglycerin Transdermal Systems is contraindicated in patients using Viagra® (sildenafil) because sildenafil may amplify the vasodilatory effects of Nitroglycerin Transdermal Systems resulting in severe hypotension.Allergic reactions to organic nitrates are extremely rare, but they do occur.
Nitroglycerin is contraindicated in patients who are allergic to it.Allergy to the adhesives used in nitroglycerin patches has also been reported, and it similarly constitutes a contraindication to the use of this product.
Amplification of the vasodilatory effects of Nitroglycerin Transdermal Systems by sildenafil may result in severe hypotension.
The time course and dose dependence of this interaction have not been studied.
Appropriate supportive care has not been studied, but it seems reasonable to treat this as a nitrate overdose, with elevation of the extremities and with central volume expansion.The benefits of transdermal nitroglycerin in patients with acute myocardial infarction or congestive heart failure have not been established.
If one elects to use nitroglycerin in these conditions, careful clinical or hemodynamic monitoring must be used to avoid the hazards of hypotension and tachycardia.A cardioverter/defibrillator should not be discharged through a paddle electrode that overlies a nitroglycerin transdermal patch.The arcing that may be seen in this situation is harmless in itself, but it may be associated with local current concentration that can cause damage to the paddles and burns to the patient.