TRANSIDERM-NITRO

What it is

Transiderm-Nitro is a transdermal therapeutic system containing glyceryl trinitrate, designed to provide continuous, controlled release of the active ingredient through a semipermeable membrane. Two strengths are available: Transiderm-Nitro 25 containing 25 mg glyceryl trinitrate with a release rate of 0.2 mg per hour, and Transiderm-Nitro 50 containing 50 mg glyceryl trinitrate with a release rate of 0.4 mg per hour.

Approved indications

— Prevention of chronic stable angina pectoris due to coronary artery disease.

Dosing overview

Therapy should be initiated with the application of one Transiderm-Nitro 25 every 24 hours. According to the clinical response, the daily dose may be titrated upwards to one Transiderm-Nitro 50, or one Transiderm-Nitro 25 plus one Transiderm-Nitro 50, or two Transiderm-Nitro 50. A patch off period of 8-12 hours, usually at night, every 24 hours is recommended to overcome tolerance. The system should be applied to intact, clean dry skin which is free of hair, and must be changed daily to minimise skin irritation with the application site changed regularly to prevent local irritation.

Key safety warnings

The patch contains an aluminium layer and must be removed before applying magnetic or electrical fields during procedures such as Magnetic Resonance Imaging or cardioversion, as well as before applying diathermy treatment. Transiderm-Nitro is not suitable for the treatment of acute attacks of angina pectoris; rapid-acting nitrate preparations are indicated to arrest such attacks. Severe hypotension, particularly with upright posture, may occur with even small doses of glyceryl trinitrate, and the drug should be used with caution in patients who may be volume depleted or are already hypotensive. Headache is a very common adverse effect due to cerebral vasodilation and is dose-dependent; such headaches often regress after a few days despite maintenance of therapy.

Contraindications

Transiderm-Nitro should not be prescribed to patients who are hypersensitive or intolerant to organic nitrate compounds or to components of the patch, who have acute circulatory failure associated with marked hypotension, marked anaemia, conditions associated with elevated intracranial pressure, increased intra-ocular pressure such as glaucoma, or myocardial insufficiency due to obstruction such as aortic or mitral stenosis or constrictive pericarditis. Concomitant use of Transiderm-Nitro and phosphodiesterase type 5 inhibitors such as sildenafil is contraindicated because they may amplify the vasodilatory effects of Transiderm-Nitro, resulting in severe hypotension.

PBS listing

Transiderm-Nitro 25 mg transdermal patch is listed on the PBS with 2 items, one unrestricted and one restricted, at an ex-manufacturer price of A$15.09. Transiderm-Nitro 50 mg transdermal patch is listed on the PBS with 2 items, one restricted and one unrestricted, at an ex-manufacturer price of A$19.78.

Regulatory history

Transiderm-Nitro 25 mg and 50 mg transdermal patches were first registered on the ARTG on 2 October 1991.