Products
Nitroglycerin has been approved in many countries since 1981 in the form of a transdermal patch (Nitroderm, others).
Structure and properties
Nitroglycerin or glycerol trinitrate (C3H5N3O9, Mr = 227.1 g/mol) is an organic nitrate. It is nitrated glycerol. Nitroglycerin exists as an oily liquid and is explosive if not stabilized.
Synthesis
Effects
Nitroglycerin (ATC C01DA02) has vasodilator and antianginal properties. The effects are due to relaxation of vascular smooth muscle, resulting in cardiac unloading and a reduction in oxygen demand. Because of its low oral availability due to high first-pass metabolism, nitroglycerin is administered transdermally. It passes from the patch through the epidermis into the dermis of the skin, where it is absorbed into the bloodstream.
Indications
- Angina pectoris
- Chronic heart failure
- Prophylaxis of phlebitis and extravasation resulting from fluid or drug administration into a peripheral vein.
Dosage
According to the professional information. The patch is usually applied once a day in the morning to a clean, hairless, dry and healthy skin area on the trunk or upper arm. The spot should be changed every day. The same skin area should be used again only after several days. Because continuous treatment often leads to the formation of tolerance, it is recommended to remove the patch at night (interval of 8 to 12 hours without patch). The patch is not suitable for the treatment of an acute angina attack. For this purpose, nitroglycerin capsules are administered, for example. For tips on administration: see Administering TTS.
Contraindications
Nitroglycerin is contraindicated in hypersensitivity and certain cardiovascular conditions (eg, hypotension, circulatory failure). It must not be combined with phosphodiesterase-5 inhibitors, such as sildenafil (Viagra, generics). For complete precautions, see the drug label.
Interactions
Drug-drug interactions have been described with the following substances:
- Antihypertensive agents, alcohol
- Phosphodiesterase-5 inhibitors can cause a dangerous drop in blood pressure and are therefore contraindicated.
- Other nitrates, NO donors, amyl nitrite.
- Dihydroergotamine
- Heparin
- NSAIDS
Adverse effects
The most common possible adverse effects include headache (nitrate headache), low blood pressure, dizziness, nausea, and vomiting.
