Glyceryl trinitrate patches

Besides its usual indications, topical glyceryl trinitrate has been used to prevent intravenous infusion failure because of phlebitis and extravasation, which occur in 30-60% of patients and can cause discomfort and harm, such as pulmonary embolism, septicemia, and increased mortality. Local application of glyceryl trinitrate patches was efficacious in several studies (11) the mechanism is probably vasodilatation and increased capillary flow. Glyceryl trinitrate is safe, since it causes only skin rashes and transient headache. 

Glyceryl trinitrate in sublingual tablets causes a burning sensation under the tongue, an indication of the activity of the formulation. Altered and later absent taste sensation developed in a patient taking long-term transdermal glyceryl trinitrate patches (15). 

In one case a small explosion occurred when a patient was defibrillated with the paddle placed over a glyceryl trinitrate patch (93). The authors felt that this was probably due to arcing of the electrical current from the aluminium backing of the patch, but they advised that patches and gel should be removed before defibrillation. 

Anonymous. Transdermal glyceryl trinitrate patches (Transiderm-Nitro). Drug Ther Bull 1986 24(2) 5-6. 

Glyceryl trinitrate patches for angina should be applied to the chest or upper arm. 

High-dose transdermal glyceryl trinitrate 50-100 mg given over a period of 12 hours each day for 3 months improved exercise tolerance and left ventricular systolic function in 29 patients with congestive heart failure taking a long-term ACE inhibitor (17). The most frequent adverse effects were skin irritation at the site of patch application and headache, which caused premature glyceryl trinitrate withdrawal in three patients. 

Nitrates can be administered by various routes. For example, glyceryl trinitrate is used not only as traditional sublingual tablets but also in the form of modified-release tablets, buccal tablets, aerosolized oral spray, intravenous injection, and topical ointment or skin patches for percutaneous absorption (23). These different formulations have been developed largely as a means of controlling the onset and duration of action of glyceryl trinitrate, since in conventional oral form its action is limited by marked hepatic first-pass metabolism. 

An unusual skin burn resulted from the application of a glyceryl trinitrate transdermal patch in a patient who was subsequently exposed to radiation that leaked from a damaged microwave oven. The patient sustained a second-degree burn of the size and shape of his skin patch, probably due to a reaction with a metallic element in the adhesive strip (94). 

In a limited and preliminary study it was reported that no blood pressure alteration was seen when a small dose of glyceryl trinitrate (amount not specified) was given as a dermal patch while subjects were taking 50 mg of sildenafil. In addition, the beneficial effects of the glyceryl trinitrate on the radial artery pressure waveform were approximately doubled, and persisted for up to 8 hours. ... 

Transdermal patches registered at present are patches containing active substances such as buprenorphine, estradiol, fentanyl, glyceryl trinitrate, nicotine, oxybutynine, rivastigmine, rotigotine and scopolamine. These transdermal patches are used in the treatment of a variety of diseases. They release the active substance during a period of 24 up to 72 h, depending on the type of patch used and the active substance. After application of the patch plasma concentration slowly rises until a steady concentration is reached. 

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