What are the adverse effects of Transderm Nitro (nitroglycerin)?

From the Guidelines

Transderm Nitro (nitroglycerin patch) is associated with several adverse effects, including headache, dizziness, and skin reactions, and patients should be aware of these potential side effects, as stated in the most recent study 1. The most frequent side effect is headache, which occurs in up to 50% of patients, especially when first starting treatment. This happens because nitroglycerin dilates blood vessels, including those in the brain. Dizziness and lightheadedness are also common, particularly when standing up quickly, due to the medication's blood pressure-lowering effects. Some key points to consider when using Transderm Nitro include:

• Skin reactions at the application site, including redness, irritation, or rash, may develop from repeated use.
• Some patients experience tolerance with continued use, requiring patch-free periods (typically overnight) to maintain effectiveness.
• Less common but serious side effects include severe hypotension, fainting, and allergic reactions. To minimize adverse effects, patients should:
• Rotate application sites daily
• Remove the patch during sleep unless otherwise directed
• Avoid alcohol which can worsen blood pressure drops
• Start with lower doses when possible Patients should contact their healthcare provider if experiencing severe or persistent headaches, fainting, allergic reactions, or chest pain that worsens or changes in character while using the medication, as recommended by the European Society of Cardiology working group on cardiovascular pharmacotherapy 1.

From the FDA Drug Label

ADVERSE REACTIONS Adverse reactions to nitroglycerin are generally dose related, and almost all of these reactions are the result of nitroglycerin’s activity as a vasodilator. Headache, which may be severe, is the most commonly reported side effect. Headache may be recurrent with each daily dose, especially at higher doses Transient episodes of lightheadedness, occasionally related to blood pressure changes, may also occur. Hypotension occurs infrequently, but in some patients it may be severe enough to warrant discontinuation of therapy. Syncope, crescendo angina, and rebound hypertension have been reported but are uncommon Allergic reactions to nitroglycerin are also uncommon, and the great majority of those reported have been cases of contact dermatitis or fixed drug eruptions in patients receiving nitroglycerin in ointments or patches. There have been a few reports of genuine anaphylactoid reactions, and these reactions can probably occur in patients receiving nitroglycerin by any route Extremely rarely, ordinary doses of organic nitrates have caused methemoglobinemia in normal-seeming patients. Methemoglobinemia is so infrequent at these doses that further discussion of its diagnosis and treatment is deferred (see OVERDOSAGE). Application-site irritation may occur but is rarely severe. In two placebo-controlled trials of intermittent therapy with nitroglycerin patches at 0. 2 to 0.8 mg/hr, the most frequent adverse reactions among 307 subjects were as follows: PlaceboPatch Headache18%63% Lightheadedness4%6% Hypotension, and/or Syncope0%4% Increased Angina2%2% The most common adverse effects of Transderm Nitro are:

• Headache: the most commonly reported side effect, which may be severe and recurrent with each daily dose
• Lightheadedness: transient episodes, occasionally related to blood pressure changes
• Hypotension: infrequent, but may be severe enough to warrant discontinuation of therapy
• Application-site irritation: may occur, but is rarely severe These adverse effects are generally dose-related and are the result of nitroglycerin’s activity as a vasodilator 2.

From the Research

Adverse Effects of Transderm Nitro

• The use of transdermal nitroglycerin patches can lead to adverse effects such as nitrate tolerance, which occurs in most patients with stable angina treated with continuous 24-hour application of nitroglycerin patches 3.
• To minimize tolerance, intermittent therapy with transdermal nitroglycerin patches can be used, where the patch is removed at bedtime and reapplied in the morning 3.
• Adverse effects at the site of application, such as skin irritation, can occur with transdermal nitroglycerin patches, but some patches may be better tolerated than others 4, 5.
• Methemoglobinemia is a potential adverse effect of nitroglycerin therapy, but one study found that continuous infusion of intravenous nitroglycerin did not significantly increase methemoglobin levels 6.
• The combined use of nitroglycerin and N-acetylcysteine may lead to adverse effects such as symptomatic hypotension 7.

Comparison of Transdermal Nitroglycerin Patches

• Different transdermal nitroglycerin patches may have varying levels of adhesion and patient preference, with some patches being preferred over others due to ease of application and removal, and adhesion properties 4, 5.
• The choice of transdermal nitroglycerin patch may depend on individual patient factors, such as skin type and personal preference 4, 5.

Specific Adverse Effects

• Nitrate tolerance is a common adverse effect of transdermal nitroglycerin patches, which can be minimized with intermittent therapy 3.
• Skin irritation and other adverse effects at the site of application can occur with transdermal nitroglycerin patches, but may be less common with some patches than others 4, 5.
• Methemoglobinemia is a potential adverse effect of nitroglycerin therapy, but may not be significant with continuous infusion of intravenous nitroglycerin 6.
• Symptomatic hypotension may occur with the combined use of nitroglycerin and N-acetylcysteine 7.